ASRock Z97 Extreme6 Tests Samsung XP941 M.2 x4, Plextor M6e M.2 x2 and Samsung 840 Pro SATA 3 SSDs


The Samsung XP941 is the only SSD on the market that is capable of PCIe x4 performance over 1GB/s at present.  As with many Samsung products, it is technically not even a retail product and must be purchased through third party resellers.


We were lucky to have the XP941 in our hands and tested long before others and, not only have we been able to test it in several different configurations, we have also been able to contribute in the advance of this technology through our input to manufacturers.


ATTO Disk Benchmark is perhaps one of the oldest benchmarks going and is definitely the main staple for manufacturer performance specifications. ATTO uses RAW or compressible data and, for our benchmarks, we use a set length of 256mb and test both the read and write performance of various transfer sizes ranging from 0.5 to 8192kb. Manufacturers prefer this method of testing as it deals with raw (compressible) data rather than random (includes incompressible data) which, although more realistic, results in lower performance results.

XP941 ASRock Z97 Extreme6 ATTO

The XP941 starts out strong with speeds of just over 1GB/s read and write performance.  A quick check of our original reports might show speeds a bit higher, but relatively consistent.


Crystal Disk Benchmark is used to measure read and write performance through sampling of highly compressible data (oFill/1Fill), or random data which is, for the most part, incompressible. Performance is virtually identical, regardless of data sample so we thought we might cheat just a bit and throw in an ‘optimized’ result.

XP941 ASRock Z97 Extreme6 CDM

It’s always nice seeing low 4K random write performance of 122MB/s, but remember, this is the result of our system being left at it’s default BIOS settings where the C States are optimized and turned off.


Up until recently, AS SSD was the only benchmark created specifically for SSD testing and it uses incompressible data.  AS SSD, for the most part, gives us the ‘worst case scenario’ in SSD transfer speeds because of its use of incompressible data and many enthusiasts like to AS SSD for their needs. Transfer speeds are displayed on the left with IOPS results on the right.

XP941 ASRock Z97 Extreme6 AS SSD BenchXP941 ASRock Z97 Extreme6 AS SSD IOPSAS SSD shows superior performance to Crystal Diskmarks and hitting 100K IOPS is ideal.  Take a look at this first file transfer speed in the AS SSD Copy Bench:

XP941 ASRock Z97 Extreme6 AS SSD Copy Bench


You may not see this for long (and it’s definitely not common) but you get a freebee simply for reading! Over the last little while, we have been assisting with beta testing new benchmark software called Anvil Storage Utilities which is an absolutely amazing SSD benchmarking utility. Not only does it have a preset SSD benchmark, but also, it has included such things as endurance testing and threaded I/O read, write and mixed tests, all of which are very simple to understand and use in our benchmark testing.

XP941 ASRock Z97 Extreme6 Anvil


The SSD Review uses benchmark software called PCMark Vantage x64 HDD Suite to create testing scenarios that might be used in the typical user experience. There are eight tests in all and the tests performed record the speed of data movement in MB/s to which they are then given a numerical score after all of the tests are complete. The simulations are as follows:

  • Windows Defender In Use
  • Streaming Data from storage in games such as Alan Wake which allows for massive worlds and riveting non-stop action
  • Importing digital photos into Windows Photo Gallery
  • Starting the Vista Operating System
  • Home Video editing with Movie Maker which can be very time consuming
  • Media Center which can handle video recording, time shifting and streaming from Windows media center to an extender such as XBox
  • Cataloging a music library
  • Starting applications

XP941 ASRock Z97 Extreme6 Vantage

123698 points is an absolutely amazing result for any single form factor SSD and it great to see true to life transfer speeds as high as 818MB/s when testing in Windows Media Center.


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    Thanks for the article Les!
    It’s great to see you opening up your reviews to more hardware while still keeping it relevant
    to storage technologies!
    I like the mobo but i still say that two 840 pros in raid 0 are still the way to go perf wise.
    That said i can clearly see the patern of where the industry is moving and that’s the M.2.

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      Can you elaborate on that? All the benchmarks suggest that’s not the case, but I could be misinterpreting the data as I’m new to the I/o performance conversation.

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        I am just happy to see the XP941 being so fast as is. For me it’s win-win as the size of my 1U’s shrink, and at they same time they get faster, and bootable. I will use them to load my data into a RAM template, and rarely write to them. Lets hope our M$ gatekeepers will let us use 24GB out of 32GBs w/o any performance issues.

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        Hi I am glad I look at this site quite often I think you do
        a real good job on everything ssd.

        Also I am thinking of buying an extreme 6- Z97 1150 socket with a 4790k canyon this xmas.

        Plus the Samsung M.2 XP941 128 I just don’t know?

        I was originally going for Asus Maximus Ranger plus the
        4790k Canyon and two Samsung 120 gb 850
        EVO SSD’s Many thanks if you can help.

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        It’s easy.
        You’ve seen the 840p results. Multiply by 2X and take -10% out.
        You’ll find that you are around the same “1GB/S” read/write territory as the M.2’s.
        BUT you also get to enjoy that sweet fast ramp up in performance in the low end up to 8K. The 4k write will also be about double.

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    Just curious, are the M2 slots eligible to be included in a RAID set?

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      Of course the could be used that way but you have to consider that the RAID set of two XP941 SSDs would be restricted to the lowest speed which is dual lane travel. That might get you a negligible improvement on the XP 941 alone in the ultra M.2 slot. Just to be sure I will try to do this prior to taking off for China in a few days…

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    I wonder…what if there were 2 M.2 x4 slots on that board….combined with 2x XP941….

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      Then any thought of decent gfx, other than integrated…might be gone. Intel needs to increase total PCIe lane count for something like that.

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        I wouldn’t care for 1x8PCIE for Graphics ( don’t think it would hurt performance much) and 2x4PCIE lanes for M.2…but you’re right…Intel needs to increase lanes to 24+ for something like this to happen properly…

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        X79! 40 pci-e lanes if using a 6 core SB-E or Ivybridge-E. Too bad it came out in 2011 and X99 isn’t here yet and no X79 boards with M.2 connectors.

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        I’m actually pretty satisfied with Intel’s iGPU.
        I’d love to see two M.2 slots running at PCIe x4, combined to RAID 0, and which can be booted from. Oh my…

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        Exactly, like if an X79 board were to sprout some M.2 connectors in a larger than regular ATX size then one would have 40 PCI-e lanes with which to delegate 8 lanes to GPU A, 8 to GPU B, 4 or 8 to your m.2 SSD’s, and use the rest for the other crap that needs to ride the pcie bus. Perhaps in X99?

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    Such a great article, so glad M.2 is finally arriving…

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    It’s great to see you opening up your reviews to more hardware while still keeping it relevant

    to storage technologies!

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    How does this m2 port work anyway?
    IS it similar to NVMe setup as these disk also uses PCIe slot??

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    can you run the samsung xp941 at Gen3 x2?

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    so the xp941 is gen2 ?

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    What about overclocking CPU? Have you tried it with this mobo?

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    I was wondering if I could use the XP941 with a PCIe 2.0 x4 adapter on a PCIe 2.0 x 16 slot in my old Dell T7500 precision Desktop?

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    LES – Great review. I’ve read the other reviews for the motherboard and the XP941. The other reviews weren’t exactly positive about two items. I figured if anyone knew it would be you.
    1. Can Microsoft Windows 7 be installed and used with the XP941 and the ASRock Z97 Extreme 6 motherboard? Some authors were under the impression that Windows 8 or 8.1 would work but Win 7 would not.
    2. Will TRIM work with the XP941 or does it have to rely on native garbage collection without TRIM?
    This year Samsung is already mass producing and distributing their new SP951 successor to the XP941. The new model is PCIe 3.0 x4 instead of PCIe 2.0 x4. How about a review?

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    Hey LT.
    Happy with the Z97 / XP941. Thank You.
    Right now I run only on die GFX and a single PCI-e 1X connector to an external Analog Devices DSP Rack, and the XP941 w/ OS+Apps. on a Vertex 4.
    So my question is can I dump my ancient Vertex 4 OS+Apps. SSD, and use the 2X M.2 with the M6e w/o any bandwidth issues.
    This means no GFX card, on die GFX only, 1 x PCI-e 1X for connections, an XP941 in 4X slot, w/ a new M6e in the 2X slot. Dual M.2’s means a new smaller 1U too.
    Have you tested both slots simultaneously….Thanks.

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    Atthapon Wongwaijonya

    Thanks you for your Review

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    hello, I do not understand, the intel i7 4790k has only 16 pci lines, and to use the PCIe x4 M.2 requires 4 lines pci espress. by connecting a video card gtx760 on x16 pci expres not work well to find only 12 ???? thank you very much

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    Can I have 2 M.2 SSDs on one motherboard? (one for OS and Applications, the other for media and gaming)? Motherboard Ex: ASUS mRampage V X99 ROG or ASUS X99 Deluxe?

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      Absolutely! You can also RAID both if you wish and, if that board was an ASRock, you could run both at 4 lanes, getting full potential.

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        Hello could you help me out with some info iv got an asrock exteme 11 x99 board and 2x 240gb ultra m.2 that i have slot in the boad is there a way i can raid them both together to make it 480gb?in the the bios i have selected raid when i reboot there is no option for raid when i press ctrl-i hope someone can help me out thank you 🙂

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    Jérôme Lanteri

    I have this mother board with i7 4470 and XP941 SSD 256Go on port M2_1. Boot on Archlinux via grub… add 2 HDD WD 2To and 1 SSD OCZ Vertex2 256Go. All on SATA3 port (not ASmedia).
    Also, i have problem with the mother board and the SSD OCZ. On the Bios, it see the SSD drive, but sometimes not read it on boot menu (but ok, this i don’t care). But… 80% of boot times, the SSD is not show and then i can not mount him. I try change port, and put him on first SATA3 port… same problem.
    So, maybe you would be curious and want to try to add a SSD drive with this config for check if this is a bug from Asrock ? I send Asrock message and let message about that on there forum, but never answer and delete the messages on the forum (i think they don’t care and just don’t want potential customers know this problem).

    Asrock use his money for provide big adds on his product, but maybe this product his far from works fine, i would like to be sure.

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    Fernando Seiti Abbe

    Recently read your article Understanding M.2 NVMe RAID SSD Boot and 2 / 3x M.2 NVME SSD RAID0 Tested . I wonder takes to put two Samsung 950 Pro 512GB in RAID and boot in my Asrock Z97 Extreme 6 on Windows 7 , and knowing that one slot M2 is X4 and another X2 , the speed would be limited to the lower, or the average sum of the two ?
    Many thanks if you can help .

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