SSD Benchmark Test: Intel SATA3 (AHCI/RAID0) vs. M.2 Ultra

Recently I have done some benchmark tests with my Z97 system running the just published Build 9879 of Windows 10 TP.
Since I was very impressed about the performance of the new OS and had access to at least 4 Samsung SSDs (1x512 GB 840 Pro, 2x256 GB 840 Pro and 1x512 GB XP741 M.2 PCIe), I got the idea to compare the performance of these 3 different, but similar sized Samsung SSD systems.
Note: My ASRock Z97 Extreme6 supports the M.2 Ultra feature. So it is able to use up to 4 PCIe lanes for the M.2 data transfer.

My question was:
Which 512 GB SSD configuration will give my Z97 system the best performance?

Under similar conditions I did a clean install of the brandnew OS onto the different System Drives (drive C:), optimized them and measured their performance.
These were the details of the test candidates:

  1. 512 GB Samsung 840 Pro SSD running in AHCI mode (connected to an Intel SATA3 port)
    SATA driver: Intel RST(e) AHCI driver v13.2.4.1000 WHQL
  2. 2x256 GB Samsung 840 Pro SSDs running as RAID0 array (connected to Intel SATA3 ports)
    SATA driver: Intel RST(e) RAID driver v13.2.4.1000 WHQL
  3. 512 GB Samsung XP941 M.2 PCIe SSD running in AHCI mode, according to >this< Review “the fastest Consumer SSD in the market” (connected to the M.2 Ultra port and bootable without any problem)
    SATA driver: generic MS AHCI driver v6.4.9879.0

Here are the results I got:
  • Single 512 GB Samsung 840 Pro SSD in AHCI mode:


  • 2x256 GB Samsung 840 Pro SSDs as RAID0 array:
  • Single 512 GB Samsung XP941 M.2 PCIe SSD in AHCI mode:


  • Evaluation of the test results:
    1. According to the overall and most of the detailed benchmark results the RAID0 array (2x256 GB Samsung 840 Pro) gave me the best performance.
    2. Second was the 512 GB Samsung XP941 M.2 PCIe SSD, which had the absolutely best Sequ. 4MB WRITE scores, but could not hit the other RAID0 benchmark results.
    3. Although my 512 GB Samsung Pro SSD running in AHCI mode was not the winner, it is still my favorite System drive because of its very good 4K READ and 4K WRITE scores.
      Note: A fast transfer of small sized data is most important, if the "normal" user wants a good performance during his daily work.

    General statement regarding benchmark test results:
    Synthetic benchmark tests show the measured data transfer speed under certain predefined conditions, but the results have only limited significance for the user's daily work.
    Consequently it is rather unsure, if the user will realize at all the measured performance differences.

    Maybe this special SSD performance test and its result is useful for you.



    @ Fernando,

    I have an interest in the XP941 on an ASRockZ97Ex6 because that is the system I just got a week ago, BUT I am only a week into discovering what UEFI is. Although I had heard the terms “UEFI” and “EFI” before, I never needed any knowledge of it. To install Win7x64 onto the XP941 in ASRock UltraM.2 , can only be done EFI which forced me into this study and discovery of this forum. There are a lot of experts including you contributing to this forum and I wish to thank all, but you Fernando are an exceptional moderator and organizer of information. This forum is evidence of that.

    I am hesitant to make statements on the XP941 because a week ago I was a complete UEFI nubie and now at best a first period apprentice, so, my place is to listen and learn, maybe ask questions for the more knowledgeable to answer. That being said, the XP941 is a pcie2 SSD but without a NVMe driver. I wish I could reference an article I read amongst the thousands of urls read the past couple of weeks but I can’t find it. It basically said that IRST beginning with 13.7… will include a NVMe driver. The article implied that random r/w’s will dramatically improve the XP941 performance over ACHI.

    The drive can also function as Sata if installed in a regular M.2 slot. The ASrockZ97Ex6 has both M.2 (shares Intel Sata cable port) and UltraM.2 PCIe2x4. I have run Benchmark tests using AS-SSD, Crystal, and Anvil with the XP941 as Sata and as PCIe2. They all confirm high sequential R/W performance of the drive as a PCIe disk and also confirm the 4k R/W random performance is just as good if not better running as a Sata drive in the IntelSata M.2 slot. AS-SSD scores Sata higher than PCIe2x4 with an overall benchmark of 1272 Sata(iaStorA to 1168 PCIe(msachi 6.1.7601) even with Seq reads of 1180 pcie vs 763 sata.

    I want to blame low random performance on msachi so it was kind of disappointing to see that the Win10 msachi driver used in your benchmarks didn’t open up the performance of this pcie2 drive. Even when NVMe becomes available, it doesn’t necessarily mean this drive would be able to utilize it, but I hope so. And if it can, the guys on this forum will figure it out.

    Thanks again for your very resourceful forum.


    @ kurt:

    Hello Kurt,

    welcome at Win-RAID Forum and thanks for your contribution.
    Maybe you should start a separate thread about the Samsung XP941 M.2 SSD and its capabilities.
    There you can post not only your benchmark results, but your ideas and questions as well.

    Enjoy your new system and our Forum!

    @ Fernando

    Hi guy, hey here I’m again asking you this time a question on your results with the XP941-M.2 SSD, your results are very good compare to mine, question don’t this XP941 uses its own driver? if don’t and use the generic MS’s, done we can use the intel’s AHCI driver, then if we can’t also use it how this card use the MS AHCI driver and where I can get the latest on from the same ver. you have test this card.

    The SATA Controller of the XP941 (DeviceID: DEV_A800) is running in AHCI mode and not supported by any other AHCI driver than the generic MS one.
    My tests were done on Win10 x64 TP Build 9879, which has an updated, very fast MS AHCI driver named STORAHCI.SYS.

    ohhhhhh ok I see now sorry didn’t look the specs at the anvil’s info, that’s where it gets the 4k higher than mine so well I guess when windows 10 comes out I will wait a while then upgrade

    this are my results:


    You may get better 4K scores by just changing the "Energy Options" to "High Performance".

    Fernan look what I did with just a 4.4Ghz on my system and I will test it changing the strap to 125 sorry guy but I’m astonished with this results. as soon as I test the 125 strap then I post the last 2 bench and quit. I don’t want to harm my SSD to expensive guy.

    As promise guy, here is:



    If those scores that you got with your system they weren’t overclock, then that MS driver is impressive cause I had to OC my system to get near yours, also as you can see the (strap) change it don’t do any difference at all. Samsung needs to make a Magician Tool version, to be able to recognize this type of SSD so it be able to use the RAPID mode feature. So there it is.

    No OCing here, the CPU runs at its default 3.5 GHz.

    … and the Secure Erase feature as well.