ASRock X99 OC Formula Review – SSD Performance Differs Slightly With the X99


The problem with all gamers and power users since the beginning of time is the lack of lanes by which to run components directly to the CPU.  With original Haswell processors, we were limited to 16 lanes, whereas the newest Intel Core i7-5820K has 28 lanes and enthusiasts are very vocal in their disappointment.  It seems that Intel, in all their wisdom, wanted us to pay for that high traffic 40 lane highway found in the i7-5930K and i7-5960K and prices of these three processors can be found at $389 (5820K), $579 (5930K) and a whopping $1049 for our sample Intel Core i7-5960X.  Looking at graphics card configurations alone, the 5820K may present some concern for those wanting to run a triple GPU configuration.

Intel i75960X CPU

The ASRock X99 Formula OC motherboard has five PCIe 3.0 x16 by which slots 1 and 2 can be used for a dual x16 CrossfireX or SLI, 1,2 and 4 (x8/x8/x16) for 3 cards and 1,2.4 and 5 (x8/x8/x8x/x8) for a 4-card configurations, all using a 40 lane CPU of course.  As soon as we can get our hands on a dual x16 Gfx cards combo, we will do some testing to see if we can completely fill all 40 lanes (ie Dual x16 SLI, Intel P3700 NVMe and Samsung XP941 X4 M2). Click on the below picture for a very high-resolution image.

ASRock X99 OC Formula MotherBoard 2

Presently, we are running the EVGA GTX 770 (X16), Intel P3700 NVME SSD (X4), Samsung XP941 M.2 X4 SSD, Samsung 840 Pro SSD, and switching off between another Intel and the Crucial M.2 SATA SSD for test purposes.  It is nowhere near what is possible to maximize lane usage, but we do hope to up this with some effective SLI testing in the near future.


We make it a habit to not check out other reports and reviews that might tie into what we are doing, but in this case it might have saved us a bit of time.  Our initial testing of the Intel X99 chip on the ASRock OC Formula brought in some less than impressive results and our main concern was whether it might be the ASRock boards fault; we don’t think so.  Had we checked out 27 or so X99 motherboard reviews (of several manufacturers) previously, we would have wondered why not a single posted review has an AS SSD, Crystal DiskMark or Anvil Storage Utilities benchmark included in its native format.

To clarify, we could find plenty of charts that speak of these tests where the finer results are displayed, but none that displayed the full picture.  Even less showed low 4K random write performance.  Kudo’s to Legit Reviews who were the only that we could find to post this report that provides a very interesting 4K write perspective with respect to the boards they tested.  Do you wonder why the Z-Series board performed better than all X-Series boards?  In the motherboard world that might not seem too obvious but, in the storage world, this is a red flag just looking for attention.


Original P3700 NVME SSD Bench (Z97)NVMe Fresh Install With Drivers AS SSD Present System


Can you identify the difference between the two benchmarks? The benchmark on the left is from a Z97 chipset and the result on the right is with the new X99 chipset.  At first, one might think that the X99 performance is improved because of the high sequential results, however, below those high sequential speeds lie 4k performance that is significantly lower for both read and write performance.  Thinking it may be the responsibility of our system OS, we conducted the test again with a fresh installation of Windows 8.1, all drivers installed and the BIOS optimized:

NVMe Fresh Install With Drivers AS SSD

We had to admit we were very impressed with 4K-64Thrd results but, 4k read and write performance was still very low.  The lesson learned here was to ensure all of our tests on the X99 board were conducted with this fresh OS.  There is definitely a tradeoff between the lower 4K and the much higher 4K-64Thrd results than seen previously.  How did this translate in Crystal DiskMark though?

PS3700 Full SpeedNVMe Fresh Install With Drivers

Crystal Diskmark tells a different story where performance seems to have dropped all around.  Does this affect M.2 and SATA performance at all?


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    Is it an Asrock difference or a matter of X99 chipset? Would you try a top competitor board to let us know?

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      If you check out the link yo the Legit report, you will see that this has manifested in other test boards as well.

      Absolutely I would try any other boards we could get our hand on.

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        Thank you for your comment. I got an Asus X99 Rampage V and my M2 xp941 512 will be arriving soon. I will report on m2 performance of the board once I get this all set up.

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        It is worth noting the large difference of EVGA X99 Classified in that review!

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        The differenc is significant, however, much lower than we are seeing from the Z97 or even 87 before that. Hopefully we can get a EVGA board in hand for testing.

  2. blank

    Did you test with any RAID cards, more specifically LSI 9260? Interested to know if it plays well with the UEFI.

  3. blank

    Any use software raiding the 2 x M.2 slots?

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      I could run two x XP941’s through this if you like, just to make sure thjings are in order. It would give you 2Gb/s in, while using as little space as possible. It also takes up 8 of your 40 count lanes (in our case) leaving some interesting options.

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        Thanks for the reply. Yea I was curious as I am very attracted to this board due to its storage options. But from my reading, I believe you can raid 0 M.2 only through software raid.

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    I have Asus rampage V x99 and 5960x, and have noe performance issues with my Intel P3700 or Samsung 850Pro’s

    P3700 @ Rampage V

    2x 850Pro r-0 @ pch Rampage V


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