RAID on the Cheap: Windows 7 Software RAID vs. inexpensive ‘fake RAID’

How good is Windows 7 software RAID? Is it faster or slower than a cheap hardware controller (aka “fake RAID”)?

This past month I’ve realized the simultaneous need to add more hard drive storage and decrease the probability of losing the data stored within. While I fully realize that redundant hard disks are not a substitute for a backup, I do want to use a RAID array to reduce the likelihood that I have to restore that data from a backup. Also, I plan to put data on that disk that I would be annoyed to lose, but it wouldn’t be the end of the world (i.e. music, movies, etc.).

Disk drives are cheap (1.5TB is currently running around $100), but industrial-grade RAID controllers are not. Being that I’m cheap, have an old (4 years is old, right?) system, and just need a bare-minimum amount of reliability I’m looking for the cheapest way to add a couple of mirrored drives. That basically means that I use a “fake RAID” hardware controller or a solution managed completely by Windows. There are various pros and cons to each, but I’ll tell you up front that Windows 7 software RAID was what I chose because of performance & trust. After the break I’ll get to the details as to why.

RAID Options

There’s plenty of advice around on what type of RAID you should use for your particular application. I recommend this Tom’s Hardware Guide write-up, and this one is also pretty good. In general, hardware RAID is better than both software RAID and so-called “fake RAID” solutions which rely upon a combination of hardware and software. But hardware RAID is expensive and overkill for my needs.

As someone who is not willing to spend the money on a hardware RAID solution, I wanted to determine the performance implications of choosing between the cheap RAID 0 (striping) and RAID 1 (mirroring) options available to me, along with the other advantages/disadvantages of each option. If you really want to get into the pros and cons of the solutions below, check out:

Option 1: Microsoft Windows 7 Software RAID

Windows has built into the OS the ability to RAID disks (since Windows 2000, I believe). The biggest advantages are that it does not require special hardware or drivers as it is completely managed by the Windows OS. This is good because if your motherboard or hard disk controller goes out, you can put those same disks in another Win7 machine and not worry about if the hardware is compatible. Another advantage, if this is important, is that you can RAID at the disk volume level – the entire disk does not need to be dedicated to a RAID (so you can make good use of unmatched disks). I particularly liked that the management of the disks is built into the Windows “Computer Management” management console.

Option 2: Hardware-Software RAID (a.k.a. Fake RAID)

Hardware RAID is exactly what it sounds like – a special hardware controller card manages the disks to provide the striping and/or redundancy. The key advantage of a full, dedicated hardware RAID is that it requires no software or drivers. That is not the case with “fake RAID” hardware cards that use a combination of special hardware and software to manage the disks. Still, hardware-software RAID should provide some performance advantage over full software RAID. In my testing, however, I did not find that to be the case.

Performance Testing Methodology & Setup

System: ASUS P4P800-E Deluxe Motherboard (Socket 478, Intel 865PE),Intel Pentium 4 3.0 Prescott 3.0GHz 1MB L2 Cache, 4 GB RAM, Windows 7 Ultimate

Drives: Two Seagate Barracuda 7200.11 ST31500341AS 1.5TB 7200 RPM 32MB Cache SATA

I used IOMeter ( to test each configuration using the same configuration. My IOMeter configuration file is located here. I ran 4 sets of tests; sequential read, sequential write, 70% sequential read + 30% sequential write, and 70% random read + 30% random write. For each test, 1GB of data was read or written in 256KB chunks. Each test was run twice to gain some (limited) measure of trust in the results.

Each test was run on two different hard disk controllers that support RAID: the Intel ICH5R SATA Controller RAID that is built into my motherboard and a SIIG SATA 4-channel RAID PCI Card (Silicon Image Sil3114r5 Chipset) – which I purchased for testing. The SIIG PCI controller was an absolute piece of crap. The included management software was buggy as hell on Windows 7, and the performance was atrocious – roughly 50% slower than the Intel controller in almost all the tests. This is to be expected, since it is a PCI card and doesn’t have the advantage of being as tightly integrated into the processor’s southbridge. Plus Windows wouldn’t build a RAID 1 on it so that configuration couldn’t be tested. For that reason, I’m not showing the graphs here but they’re in the attached Excel file for the curious.



Windows RAID performed just as well, if not better than, the hardware controller RAIDs tested and Windows always incurred the lowest CPU utilization. The results are a mixed bag, where there were some cases where Windows did somewhat better than the Intel RAID and others where the HW solution did slightly better. The key take away from the performance results are that the speeds were all within a few MBps of each other, which I consider to be in the noise, while Windows used less CPU consistently.

All of the raw data is in this Excel file.

Sequential Read Tests



Sequential Write Tests



Sequential Read/Write Tests



Random Read/Write Tests





Supposedly the main advantage of a fake RAID is that is should perform better than full software RAID, both in the disk transfer rates as well as CPU load. And that may be the case for some configurations, but I did not find that to be the case in my testing. Windows performed just as well as the “fake RAID” with a slightly lower CPU load. Given that I’m more comfortable with the Windows management consoles than the software provided by Intel to manage their RAID, I chose to mirror my drives via Windows RAID 1.

Additional notes

I don’t claim that your results will be the same as mine – I ran these tests because I was curious. If you disagree with the results, or have a different opinion, that’s cool. I’m not here to debate you. I just wanted to share my findings in the hopes that it will be useful for someone else in a similar situation. Please feel to comment if you get a different result or have experience. Enjoy!

111 thoughts on “RAID on the Cheap: Windows 7 Software RAID vs. inexpensive ‘fake RAID’”

  1. Pingback: RAID on the Cheap: Windows 7 Software RAID vs. inexpensive “fake RAID” at Kevin’s Blog « Genius-Field
  2. Thanks from me too. For various reasons SW RAID was my only option, at least now I am sure I am not missing out ;)

  3. YES. Thanks for this! Excellent info. It's too bad the RAID1 doesn't take increase read speed in a similar way as RAID0…..

    1. The solution your looking for is called "Raid 10" or in other words "Raid 1+0" which a lot of more recent controllers can do, and it means 4 HDD's but you get the benefits of "1" MIRRORing as well as the SPEED benefits of "0" SPANning.

      1. Are you sure? A smart raid 1 should be able to read a file from both disks simultaneously, only the write part is not accelerated.

        1. I agree with you Arend.
          I find it really strange that here the raid 1 is so slow in Reading, it should be the same speed as raid 0 when reading.

          1. I think the difference here is due to the buffering and access pattern. I only did sequential read tests.

            On RAID 0 (striping), you can get the full advantage of having twice the buffer space on the disks while reading the data back. While Disk 1 is buffering its first 8MB interleaved of data, Disk 2 is also reading/buffer in its 8MB of interleaved data – together, they've buffered the first 16MB of sequential data which they can quickly feed to the controller.

            By contrast, on RAID 1 (mirroring), both disks are reading identical patterns of data. So, while Disk 1 is reading/buffering 8MB of data, Disk 2 is also reading/buffering roughly the same 8MB of data. Thus, those disks together can only buffer about 8MB of sequential data at any moment in time.

            1. This sort of buffering is important for the sequential read/write testing – it is not as important in the random cases. Note that, in the mixed random tests (the only random test I did), RAID 0 actually performs better. This makes sense because the buffering and spacial locality doesn't help much, but the independent heads seaking different areas of the two disks should make the random reads faster. Buffering may not be the only reason – but I think it is a good candidate explanation.

  4. I want to say thanks for posting your results as well. I have been hunting high and low for a decent Windows S/W vs Fake RAID comparison, this is just what I wanted to see.

    1. Cool! I'm glad you found it useful. Please do let me know if you run similar tests and if your results match up.

    1. I'm glad you've found it useful! Let me know if you run any similar tests and confirm/deny my findings. Given that these results are run on older hardware, I'd be curious to find out what results others get on newer controllers.

  5. Kevin, your review missed 1situation which most home users may find handy to know ….

    Q. How long does it take to ReBUiLD a MiRROReD ARRAY using Windows Raid "1" compared to a Hardware (or Hardware/Software) controlled Raid "1".

    I would 'presume' that a "rebuilding of the array" scenario will show the hardware controller is then much faster than Windows' "software only" controlled method.

    Apart from that Kevin it's a very good review for most of us home or SOHO PC users.


    A 2nd question is: Windows Raid driver can do 0,1 & 5, BUT can it also do 10 (1+0)?

    Raid 10 (1+0) through the Windows driver – if it were possible, would gives the user MiRRoRing (or DATA Retension) as well as SPeed advantages through SPANning?

    To get 50% HDD redundancy or better meaning the user won't Loose their Data (that is replacing 1 out of 2 or 2 out of 4 corrupted/dead HDD's) the user really needs to select either RAID 1 or 10(1+0), which I think means having to use a hardware controller.

    (Final Thought: I wonder if but doubt that it's possible to set up Windows 7 first as a mirrored array and then take the mirrored array and span it???)

    1. re: rebuilding a mirrored (RAID 1) array with Windows 7 – honestly, that is the least of my concerns since it's the most uncommon case. Even if it took 10x longer to rebuild with Windows (which it doesn't) it woudn't be worth sacraficing my daily performance. I actually tested the time it took to rebuild using my controller and within Windows and didn't find a differerence in the time worth mentioning (and I no longer have that specific data, unfortunately).

      re: RAID 10 – I did not consider RAID 10 because I think it's overkill for a home user like myself. I did it to give me a little more protection against the loss of media that I'm not willing to backup – replaceable movies, music, and the like. I do backups of the data I care about losing onto removable media, and RAID the stuff I'd only be mildly bummed about losing since RAID shouldn't be used as a backup solution _ever_.

      1. After 2 yrs of happiness with W7mirror, suddenly my whold machine performance is zapped and the mirror set (700GB active storage on pair of 1.5TB Barracudas) is constantly resynching. Have tried break and re-make the mirror set, but the result is the same. It never ends resynching, with a physical disk writing activity (onto the target disk) of only 5-7MB/sec, instead of the normal 70-80MB/sec of the source disk and other disks on the system.

        I have googled around and this is a common occurrence and it appears that W7 WU is the trigger, as it updates one disk alone.

      2. KM – thanks for sharing your surprising conclusions with the World – as most didn’t expect a Soft RAID to utilize CPU% less than a hard RAID.

        you wrote: “I actually tested the time it took to rebuild using my controller and within Windows and didn’t find a difference in the time worth mentioning.

        I would incorporate this into your blog post. many people have abnormal shutdowns for whatever reason, so RAID1 recovery and rebuilding time and reliability differences between soft and hard RAIDs are more important to some than you seem to believe.

    2. When I say SPANning I actually meant to write STRiPing. (my mind was elsewhere when I wrote the reply) Sorry.

      If I recall correctly … I think only Windows Servers and then mainly the Enterprise version of other Windows Operating Systems can do Raid 5 via software only.

      1. Windows 8 can do software RAID 10. Windows 7 and below don't because the method of setting up RAID in these versions through the "Disk Management" utility with their "Dynamic Disks" doesn't. (So far as I know). The gotcha is that Windows 8 still lets you do things that way if you want, so many people don't realize there is a new approach in it which supercedes that. Instead of using Disk Management in Windows 8, what you can do is create "Storage Spaces". Storage Spaces are a way of abstracting RAID so can be a little head-scratching for those of us who are familiar with RAID – like going from a stick-shift to an automatic. But if you create a mirrored Storage Space with multiple columns what you've just done is create a RAID 10. Columns are how many disks the data is striped across. The mirror number (e.g. a 2-way mirror) is how many copies of the data there are. Once you get past MS's non-standard terminology, it's pretty good performance-wise.

  6. Hi Kevin,

    how did you manage to install drivers for intel sata raid built into ICH5R on windows7? I have the same board and I'm trying to do that for the past several days without success …


    1. Hi Sasa,
      First, I think Windows 7 actually has the drivers built in that will work. It just won't give you the fancy control panel inside of Windows. I just used the Bios to make all of my changes. However, I did find a couple of driver packages from Intel that I ended up installing while I was playing around. I found them on Intel's site – I believe they were the Matrix Storage Console for the 82801ER chipset.

  7. The Intel ICH5R was never meant for windows 7 and newer intel southbridges have brought significant performance improvements in the RAID area. Since this chipset is from 2003 I would strongly recommend anybody who is looking to buy a new system now and is basing his decision party on the RAID performance to leave this review OUT OF CONSIDERATION! The chipset as well as the CPU are hopelessly outdates. what amounts to 10% processor load on this machine will make a mere 0.5 on any Core iX system and maybe to 1-2% on a decent core 2 system. Same applies to recent AMD processors.
    The best solution in price/performance at this time is a 3rdparty fakeraid controller (I.e. Highpoint RocketRAID 2680 or similar) which are cheap because they have no IOproc but outperform any onboard RAID controller as well as softwareRAID by miles! (Altough softwareRAID would also benefit from the use of one of those!)

  8. we are using A Gigabyte Mobo RAID and W7 Ult 64, we found out we got VPS and SPP errors with the Backup from Windows…

  9. Got this duet external hard drive from it has built in riad and esata.. and costs less than win 7 .. why bother with anythign else ? Got Raid 0 raid 1 and JBOD + esata host and usb host.. fantastic kit .. nevr failed (well so far)…

  10. Random question. I am using Windows 7 RAID 1 on 2 1.5 TB Seagate HDs and randomly, they both just quit working on me. I unplugged them and plugged them back in and they finally showed back up, but one of them had to be reinitialized. I'm currently in the process of resynching the raid (which has 500gb of data). What do you think the cause of that could be? It worked until I restarted 1 time, then 1 drive was corrupt and I couldn't do anything with the raid setup.

    1. Green drives. I had the same problem with WD Greens they would spin down and when i probed them and one was still spinning the raid would go off line. You can change these setting some times though.

  11. Also, don’t forget that hardware raid usually prevents SMART data to be read by programs like HWMonitor so, you can’t see ie. the temperature of the HDDs. But with software raid, you’d have access to the physical HDD and it’s S.M.A.R.T. data because it’s no longer filtered by a hardware raid…
    So, I’m switching to software raid mainly because of this; I want to see the temperatures :)

  12. @Daniel: Seagate’s 1.5T drives suck. Badly. I had one and it died very quickly. The vendor said they were having lots and lots of returns. I went with a 2T WD and never had another problem.

    For RAID, though, I’d stick with 1T or smaller drives, since they perform better. Also, depending on which RAID, you have to be careful which drives you get, since some of them aren’t RAID friendly. WD, for example, charges more for the RAID friendly drives, and it’s just a minor firmware tweak that does the trick. The price, however, is quiet a lot more (though the warranty is better, too).

  13. Pingback: Cheap RAID 5 controller recomendations please - Page 2 - Hardware Canucks
  14. This review was great. I recently set up a media centre pc in my living room, I started from scratch using a full ATX media case and silent hardware… I got 8 2tb disks running raid 1+0 to give me 8tb of storage, all redundant and super quick to read/write. If you are asking "why???"; I have 700 HD movies, about 2,000 TV episodes, about 10,000 photos, 16,000 songs… Screw losing all that, and screw putting it all to ten billion DVDs or BDs…

    1. By the way… I totally forgot to mention, it was windows raid i used… Main reason was, if my MB died or something… I could simply move the drives or one mirrored half of the array to another computer.

      1. Thanks for the feedback. Glad it was useful for you. I'd be interested in seeing someone else run these performance numbers and report back to see if they have similar results.

      2. Thanks for the feedback. Glad it was useful for you. I'd be interested in seeing someone else run these performance numbers and report back to see if they have similar results.

    2. Thanks very much Kevin for this great interesting article and even more interesting discussion…
      Damo, your comment was actually most interesting for me, because I am just going to set up a new PC for similar purpose (my media library is not so huge at the moment, but it is growing quite rapidly…).
      I don't know, if you will read this reply after so long time, but in case you will, I have several questions for you (or for some other good guy who will be able to answer):
      1) Is it normally possible and easy to set up the 1+0 RAID as a software RAID in Win7? I have read some articles saying that this is not so easy or kind of problematic, but no one of them was completely clear…
      2) Does this Win7 SW RAID give any warning in case of failure of one of the disks from the array? I have read some articles saying that Win7 RAID does NOT have this feature (or at least it is not possible to set this up easily) and it was one of the arguments why to use the "fake HW RAID" instead.
      3) Do you think it is possible to start first with just 2 disks in RAID 1 in the beginning and then later on extend it to RAID 1+0 to increase both speed and capacity?
      My idea is following:
      – buy a motherboard with enough SATA connectors (and a case that is big enough :-) ) – my current choice is ASROCK Z77 Pro4
      – start with 1 SSD HDD for OS + 2x classic 2TB HDD, which will be set up for RAID1 in Win7
      – later on (maybe in a few months) extend the array by another 2x 2TB HDD and set up the array into RAID1+0
      Thanks Damo or anyone else in advance for answering and for letting me know whether my idea is feasible

  15. Hi… one of my HDD faild and i lost 1T of movies/music/TV shows/pictures so i decided to make a raid 1.
    I wanted to go with a hardware solution for that (having in mind that my MB was supporting raid, gigabyte p55-ud4) but because i installed windows with the intel controller set to IDE (not raid) and i didn't wanted to reinstal/fix window after changing to raid, i used the secondary Gigabyte controler (based on JMicron tech).
    Now, my question is this: i configured the RAID 1 in the post BIOS raid screen but after windows booted it didn't asked for any drivers. Is that a REAL raid controler? or still a fake one with drivers that win7 installed automaticly?

    1. It's most likely a software/hardware RAID and Windows likely installed the drivers for it automatically. Real raid controllers typically cost 10x the fake raid versions, so you generally know what you're paying extra for.

  16. Thanks for this nice review.

    I do have one question… when you talk about software raid, I believe that you cannot put Windows on the raid, so it looses interest no ? I understood that you install Windows, and let's say you have a minimum of two disque. You partition the Windows disk partition in 2, but you can only combine the 2nd partition (the one without Windows) with the other disk for stripping. Am I correct ?

    1. Yes you can. When you are doing a clean install you can choose the Disc configuration and at that point . RAID 1 needs nothing special it does not change your primary disc.

  17. quote: "In general, hardware RAID is better than both software RAID"
    Excellent and useful article, but I disagree with the above. hardware raid is not much faster, if any. The clincher is this: Disks used with hardware raid are usually tied to a specific manufacturer and sometimes to a particular model of raid controller. This means if a disk fails you are OK, but if a motherboard or raid controller fails you cannot recover your data unless you purchase a new motherboard or a new raid controller of the same make and model. If you use SW raid, tho, you can just pull the drives and install them in another system to recover the data, and you need not ever purchase another raid controller, and you don't have to wait for shipping etc to recover the data.

    1. Good points. By 'better' I believe I was intending to say 'faster'. How much faster, I have no evidence of. I only know what I've been told, since I've never owned a hardware RAID solution myself. All I do know is that the very few people I know who have spent a few hundred $$ on hardware RAID cards sware by them with respect to performance. In theory, it does make sense, particularly if you're running CPU bound workloads and you want to offload the (little) processing that a software RAID solution incurs to the card.

      I completely agree with you that software RAID has big advantages in terms of not being tied to specific hardware. That's one of it's biggest selling points for me.

    2. Hi Glen,

      I have the situation where I have to install my drives in another system. I have an XP software raid 5 array. How would I go about recreating the raid 5 array and recovering the data?

    3. And Glen worstell, You dont even have to purchase a disk of the same size or Connection eg It must be same or bigger but can be IDE or SATA.

      I have been running such a RAID of two disks, one IDE, one SATA and it has def speeded things up. However I really wanted to speed up the Boot and suspend. The overhaed in CPU is completely unnoticeable (C2d), and worked like a charm (all this on XP).

      I would really like RAID5 over three Disks, with ability to extend.. but RAID0 is good enough for now.

  18. Hi,
    You say "if your motherboard […] goes out, you can put those same disks in another Win7 machine".
    Are you sure about that? Have you tried? Because I doubt that windows would be able to create a raid without formating the disks.

    1. Yep – you can try it out yourself. After the RAID has been created on the disks, all of the information for another Win7 machine to read them is contained on the disk themselves. In fact, you can take a single RAID 1 disk and put just the one disk in another machine and it should read just fine (although it will report that it's partner is missing). My understanding is that this is the case for any RAID implementation – the only difference with HW-based solutions is that you have to get an exact match of your HW controller to read the disk in another machine.

    2. Olivier asked: "You say "if your motherboard […] goes out, you can put those same disks in another Win7 machine".
      Are you sure about that? Have you tried? Because I doubt that windows would be able to create a raid without formating the disks."

      This question seems not to have been answered. I can't answer for Win7, but can for WinXP; I expect but cannot guarantee that Win7 will be the same. There was a tutorial a few years ago on setting up a WinXP machine with RAID 0, 1, or 5, patching 3 system files to enable RAID support which was built in but disabled. I have been using this setup for years. I have not myself made the test, but the article was very clear: drives can be removed from one machine, plugged into another with a different SATA controller, and they will work without reformatting. The article says "we did not expect the swapping to be so smooth … Getting the four drive RAID 5 array running on another system was enjoyably easy. Nothing had to be reconfigured, and we even picked SATA ports arbitrarily."

      1. For a RAID 1 config, I'm quite certain you can pull out a disk and slap it into another machine with no problem. Afterall, they're just mirrored. :) This I did try with my setup.

        For a RAID 0 config, I'm fairly certain you can transfer the disks from one Windows 7 machine to another, but I have not tried it myself. The key with most RAID configs, as I understand it, is to use the same 'controller' that laid down the bits when you move the disks. In a HW RAID 0 config, you'd have to get the exact same controller card to be able to move the disks across machines. For SW raid, it's the OS doing the controlling so you should need no special hardware – just the same software.

        I'd love to hear from anyone that's tried this for themselves. Since I don't have a RAID 0 config, I can't prove or disprove it – and I haven't dug up specific docs on Win 7 saying either way.

    3. I can do one better – I had a system drive fail and decided it was a good time to update from XP to Win7. Installed 7 not even thinking about the fact that I had a pair of Windows RAID 1 sets (via the directions to enable it in XP on Tom's Hardware).

      Windows 7 had no problems with the RAID 1's that I'd built in XP. IIRC I had to go into the drive management and enable the drives but that was it.

  19. I'm using Windows 7 and have installed it on software mirrored volume.
    I had blue screen after unexcepted shutdown.
    STOP: 0x00000058

    To recover the situation I followed these steps:

    1. Startup with recovery and select advanced options
    2. open cmd prompt
    3. diskpart
    4. list volume (C volume shows status as "failed rd")
    5. select volume XX
    6. recover

    It takes some time to rebuild the mirror, check the status with "list volume" and look up that disk activity has been ended before you restart.

    Another option (and faster to get back to windows) would be breaking the mirror, then rebuild it from Windows using disk management, but haven't tried that.

    Any comments?

  20. Hello Kevin. Wanted to make a comment about hard raid vs soft raid. Actually, soft raid is usually better for all cases but one – high load sever. Hard raid (providing it was made by a quality manufacturer – and that would cost you) can have only to advantages – it takes of the load from your main CPU when there are lots of action going on here and there on the data (multiple readwrite operation on distant sections of the HDD platter), and it has an emergency power reserve to finish any writing operations in case of power failure. If you are talking a typical homesoho file storage, which is not involved in 247 random write operations – software raid is the way to go.
    With media server – most files will simply be written once and than just read over and over again, with no CPU load at all. I`m using a self made NAS at home, AsRock motherboard with built in ATOM D410, running Freenas and 2 X 1TB drives in software raid mode, and i`m yet to see the CPU load over 20% even with torrents on.

  21. I've been using Windows Home Server instead of a true RAID solution. However, over time, I've had to add more and more drives to my setup that I've actually installed 2 RAID cards in my WHS setup. I've linked each drive associated with each RAID card as JBOD – after all, I want WHS to manage my system, not RAID, right? Unfortunately, I've noticed that my WHS machine has just become too incredibly slow for my taste. I get 10-16MB/sec transfer. It's deplorable. I'm now in the process of copying files to new hard drives that aren't WHS – they're just drives in a Win7 box … and it's taking forever. I was considering turning my WHS into a Linux backup box with RAID in it, but that'd defeat the review you completed above re: Win7 RAID. In case anyone here is still reading this review: what's better for a backup machine, WHS, Win7 backup, or Linux with RAID card (fake raid) installed?


  22. Hi dudes, have a question about how to return to mirror state after removing one of the drive through Disk Management? They worked in software RAID 1, and of course I tried if is it possible to re-mirror the drives after breaking it – nothing is copied on both disks, the system was immediately shut after that.

    OS – Windows 7 x64.

  23. Looking at your tests, I can notice that Windows RAID 0 performs horrible compared to Linux' mdadm (which actually DOUBLES performance in case of R0, not increases it by just ~50%).

  24. Pingback: Setup RAID 1
  25. Thanks.
    It looks that I have the same kind of old board: P4P800-VM.
    The cheap VT6421 RAID controller chip is not stably detected in BIOS.
    When I was thinking about the software RAID in windows 7, I have seen this article.
    Thank you for sharing info.

  26. Pingback: Raid 0 on gaming laptop - -
  27. Can we do Software RAID-10 with Windows Server 2008 R2 Standard x64 ?

    I would like to put four WD enterprise disk in RAID-10.

  28. "Supposedly the main advantage of a fake RAID is that is should perform better than full software RAID, both in the disk transfer rates as well as CPU load"

    I don't know where you came up with that from. They have never been marketed as higher performance than software raid. FakeRAID solutions are called "fake raid" because they have all the disadvantages of hardware raid (non-portable. your raid card dies and you're only ensured to get your data back if you buy another identical card) and all the disadvantages of software raid (slow). The only advantage of FakeRAID is that it shows up as a single disk in your OS, which might make things easier there.

    Literally the difference between FakeRAID and software RAID is that the fake raid controller has a BIOS attached to flash memory. You can use the BIOS to configure your raid setup and then the driver looks at the settings from flash memory. After that it's all software raid. Absolutely nothing is done on the FakeRAID hardware to make them any faster. All the magic is done in the driver. They are literally a standard SATA controller plus a raid bios/flash memory. Please stop telling your readers that "supposedly" offer a speed boost. They have never been advertised as such; not to the ODMs, not to the OEMs, and not to the Consumers. If you made that conclusion it's because you or someone you were talking to made it up.

    1. I have actually heard folks claim that "fake RAID" solutions should perform better – that was one of the reasons that I wanted to run these tests. I wasn't sure that I believed those claims. And my numbers showed that they weren't really true – I believe data, not rumor. The word "supposedly" was chosen for exactly that reason.

      You're correct in that there is little to no real hardware advantage that fake RAID controllers provide – I've heard claims that the drivers that enable the RAID often work better than the RAID provided by the OS, or that "Fake-RAID can have solid performance due to high bandwidth, low latency interfaces to the CPU" due to close ties to the CPU's south bridge <a href="http://(” target=”_blank”>(

      I think it is important to validate these things for one's self.

      1. The reason it's called "fake RAID" is to distinguish it from RAID that is performed by a dedicated controller card and *presented to the BIOS and operating system* as a single large disk. Hardware RAID controllers have a powerful CPU specifically built for the task of managing the RAID array without requiring any help from the host system's CPU, plus a large chunk of on-board RAM for disk read/write buffering and caching.

        "Software RAID" is the term used for what Linux does with the 'md' and 'lvm' drivers and what Windows does with dynamic disks plus spanning/striping/etc.

        "Fake RAID" is called such because it simulates a hardware RAID controller from BIOS initialization all the way to normal OS operation, but this is done only through a combination of two software parts: there is an option ROM present that will present a single RAID disk to the BIOS (so the BIOS can boot even from a fake RAID-5 since the option ROM has the code) and there is a storage controller driver for Windows (iaStor, amdsata, JRAID, etc.) that presents the same single large disk to Windows and does the RAID translation internally.

        The difference between software RAID and "fake RAID" is where the RAID logic is located and how the disks are presented to the operating system at the lowest level. The difference between hardware RAID and software/fake RAID is where the RAID logic is located and which CPU has to do the low-level RAID work.

        Paul's statements are roughly factual but are not necessarily 100% correct. "Fake RAID" can potentially be faster than Windows software RAID because all of the RAID logic is in the low-level block device driver and that driver knows a lot more about the underlying hardware than the generic block device code in Windows does; because of this, the vendor's fake RAID driver can work around hardware bugs that cause a performance penalty when triggered and can optimize block-level transactions to the RAID array for the specific disk controller in use. Software RAID generally has no knowledge regarding the underlying hardware; it's a logical mapping and the algorithms are (by necessity) tuned for the average case rather than the specific controller(s) being used. In practice, the performance difference between the two software-only RAID implementations is often negligible since modern hard drive controllers and drivers are fairly bug-free and engineered quite well.

  29. Paul, you are a tool. This is just a blog post, no need to get snarky. If you read the comments, most people, if not all, have found this helpful, as did I. Get off your high horse.

    Kevin, thanks man, this helped me decide to try it out for myself. I now have 2x 1.5Tb Samsung drives in a RAID 0 software array, which works well even between switching from Win7 to XP. Only wish you could use the RAID drive as an OS install drive… or maybe you can… IDEA! will let you know!

  30. Kevin, thank you very much for sharing so many details about your test. I was interested in the same information, but I have an ICH9R. I took your file and parameters and did the same tests between Windows 7 software RAID and the ICH9R. If you would be interested in posting the results, please let me know and I'll send you the Excel file.

      1. Results were different and convinced me to use Windows 7 raid. The test pages were changed some since I'm using a 4 core processor. I added a test for the Intel RAID cashe on vs off. Also, for fun I tested my 4 identical drives I was considering for RAID. The tests were done with the latest Intel ICH9R drivers.

          1. Thanks for sharing this xls with ICH9R. I just bought a new Z68 motherboard with ICH10R and I need to decide between "MB Raid 1" and "Win 7 Raid 1". And from your results I see that Read performance from the Win7 Raid 1 is almost 50% better. Thanks.
            I need just one clarification. The "HW RAID 1 Cache" on the charts is exactly what?

  31. Kevin, thanks for sharing your findings. I was researching fakeraid vs software/os raid and this was quite useful.

    On a side note, I've been using fakeraid (ICH10R) for about 2 years now. Read/write speeds have been fine, and not a reason for concern. I recently added a 1.5 TB drive to my existing array (3 x 1.5). The raid expansion and related data migration process is taking forever; beyond any semblance of reason. Its been a few hours over 1 week now, and its only reached 58%.

    Couple of questions:
    – Should it take this long?
    – CPU utilization is very low, between 2% and 5%. I'm guessing the bottleneck is the HDD?
    – Would a rebuild (if called for in the future) take this long?

  32. Interessting test but you have to watch out for those Seagate drives.
    This type of drive can block or become a "brik" because there is a bug on the firmware.
    You can flash the firmware to a newer version to avoid problems.

  33. Thanks for this useful article !

    I do have a question. Imagine you have 3 drives :
    – SSD: 120 Go (Windows + progs etc)
    – HDs: 2 x 2To (for personal data) in raid 1, so 2 To available

    The question is:
    Can you recover your data if your windows OS is corrupted (virus, human error…) and you need to format the SSD ? The fresh install windows will recognize the raid1 or not ?

    1. Yes, you should be able to. It should be pretty easy to test out – pull the drives out and slap them in another machine, they should be recognized just fine.

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  35. Thanks for the write-up, your findings re-affirm my experiences with software and fake raid. With software raid it is also actually easier to dual boot as ironic as that may seem.

  36. Pingback: Two 240GBRevoDrive3 X2 in RAID0! Possible! Results? 3.17 GB/s read, 2.6 GB/s write!
  37. Thanks for taking the time to write this out bro.
    I'm new to RAID and was wondering which is better.
    This has been very informative.

    You Rock! :D

  38. ". The key advantage of a full, dedicated hardware RAID is that it requires no software or drivers"

    BS. Windows will not even boot to some RAID cards without drivers.

    1. As I understand it, If Windows won't boot it without drivers, it is not a full hardware RAID. Fake RAID solutions require drivers.

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