Slow WD Black 512Gb

Hi, i have an pretty old computer based on an ASROCK Fatal1ty 990FX Killer, AMD FX 8350, 16gb ram @ 1600mhz.
I belive it is pretty much the first motherboard equipt with an M.2 slot, just x2 but it should acording to tests be good upp to 700mb/s.
So i bought an WD Black 512 just to get some more speed and yes it reads as expekted but it writes terrible, what have i done wrong am i missing something ?, or had i just too high hopes ?.
Did Crystal disk mark on it and compared it with my old cruzial 500, comparison below.

Wd Black 512
Sequential Read (Q= 32,T= 1) : 811.975 MB/s
Sequential Write (Q= 32,T= 1) : 552.676 MB/s
Random Read 4KiB (Q= 32,T= 1) : 222.995 MB/s [ 54442.1 IOPS]
Random Write 4KiB (Q= 32,T= 1) : 93.309 MB/s [ 22780.5 IOPS]
Sequential Read (T= 1) : 648.452 MB/s
Sequential Write (T= 1) : 628.406 MB/s
Random Read 4KiB (Q= 1,T= 1) : 39.784 MB/s [ 9712.9 IOPS]
Random Write 4KiB (Q= 1,T= 1) : 87.656 MB/s [ 21400.4 IOPS]

Cruzial 500
Sequential Read (Q= 32,T= 1) : 523.719 MB/s
Sequential Write (Q= 32,T= 1) : 268.832 MB/s
Random Read 4KiB (Q= 32,T= 1) : 152.150 MB/s [ 37146.0 IOPS]
Random Write 4KiB (Q= 32,T= 1) : 128.202 MB/s [ 31299.3 IOPS]
Sequential Read (T= 1) : 420.288 MB/s
Sequential Write (T= 1) : 273.462 MB/s
Random Read 4KiB (Q= 1,T= 1) : 17.860 MB/s [ 4360.4 IOPS]
Random Write 4KiB (Q= 1,T= 1) : 33.446 MB/s [ 8165.5 IOPS]

Supports Gen2 whereas the WD Black 512 SSD is Gen3. I’d imagine the motherboard may be the “bottleneck” for the relatively slow speeds you’re getting versus what you’re expecting to get. From your ASROCK’s product specs page: “ASRock’s motherboard is the world’s first and only motherboard that implements a Gen2 x2 M.2 socket”

Maybe this explanation from a ComputerShopper SSD review will help:

“Until a year or so ago, most of these M.2 PCI Express SSDs made use of the PCI Express Gen 2.0 x2 interface, which defines a throughput ceiling that’s higher than SATA 3.0’s, but not enormously so.”

Overall, you’re getting very fast performance. Unless you’re losing money betting on SSD speed races, don’t fret over what amounts to a minimal performance issue. Upgrade to a board with newer, faster specs, and those scores you posted will increase, but in everyday use, you’re not going to notice the difference. Throw in one of my 1TB WD Caviar Black HDDs… then those numbers start becoming significant.

Too high hopes then.

yeah you need to check “Turn off windows write-cache buffer…” in device manager, SSD drive, Policies

you should get advertised speeds :slight_smile: I have the slower 256Gb but I get 1700Mb/s read and 670Mb/s writes with that option checked

With the hot garbage “windows write buffer” I get single digits Mb/s writes and reads on this x4 ssd

Busken, I do hope that you have read the follow up on this and tried it. Do let us know the results if you do for I am considering purchasing a WD 512GB unit if it gets these write speeds on my MSI 970A Carbon system with a Gen 2 M.2 slot. It will not be worth it to me to get such slow write speeds. I am using an AMD Athlon & would love to have a Ryzen but would have to toss away 32GB DDR3, new MSI Mother board as well to use it. Too expensive for me.

I am searching for data to use the WD Black 512GB PCIe with NVMe on my MSI 970A Gaming Pro Carbon with an AMD Phenom II and wanted to find out about compatibility problems such as these. The specs say that reads are up to 2050 MBS and writes are up to 800.

I do want to know if the WD unit is compatible with the MSI AND if I can use other SSD’s in my server with no conflicts. Some info states that this WD unit requires that the full system be “UEFI ONLY” and that does conflict with my WD 4TB and other smaller 1TB Seagate drives. The MSI is also Gen 2(M.2 Slot - 1 x 2280 Key M(PCIe Gen2 x4/SATA)) while the WD Unit is Gen 3, I read here, but also that it may not matter if I turn off write buffer in Device Manager, will still get the same speeds as Gen3. Will appreciate any words. Want to purchase in a 2 month time frame, catch the hottest sale prices of the year.

Will submit my request as a new pre-sales item in a new post.

If i turn the buffer off it realy do write slow, i have tested with it on all the time.
Uppdated the AMD driver it did get better.
If i compare it with my old ssd it is much faster on paper, in real World it is litle faster not by OMG standards.
Latest run and i Think it is as fast as it gets .
Sequential Read (Q= 32,T= 1) : 810.885 MB/s
Sequential Write (Q= 32,T= 1) : 627.552 MB/s
Random Read 4KiB (Q= 32,T= 1) : 219.764 MB/s [ 53653.3 IOPS]
Random Write 4KiB (Q= 32,T= 1) : 188.307 MB/s [ 45973.4 IOPS]
Sequential Read (T= 1) : 649.694 MB/s
Sequential Write (T= 1) : 624.736 MB/s
Random Read 4KiB (Q= 1,T= 1) : 39.318 MB/s [ 9599.1 IOPS]
Random Write 4KiB (Q= 1,T= 1) : 85.967 MB/s [ 20988.0 IOPS]

Thanks Much,

This really affects my decision as I want to buy real OMG speed increases but there seems to be some bottleneck between the theoretical and reality. Let’s face it, Real sequential reads of 810 MBS vs theoretical reads of 2050 does not start the saliva to flowing. The rest of the specs say pretty much the same. I may just get a 2TB unit, either a Blue or regular SSD to satisfy my needs as the industry focus’ on Ryzen hardware to bring the promise together with reality. The additional price is not justified by the performance improvement, in my estimation. I love the joys of putting it all together myself so that I know each part is best for the complete system.

This theoretical puts NVMe drives very close in to actual ram, which will be great when they get the bugs out. If I find a great solution before Xmas, I will still pop for it. If not, well, I will still live.


I got the similar problem with ssd black nvme 500GB. The result showed above. I am using MSI laptop i7 gen 5 HQ. For the cold start for my windows 10 is around 40 seconds including the log in page.