Samsung SM951 (512GB) PCIe SSD Review
by Kristian Vättö on February 24, 2015 8:00 AM ESTSequential Read Performance
Our sequential tests are conducted in the same manner as our random IO tests. Each queue depth is tested for three minutes without any idle time in between the tests and the IOs are 4K aligned similar to what you would experience in a typical desktop OS.
The sequential tests really show the benefit of PCIe 3.0 because the SM951 is approximately three times faster than a SATA 6Gbps drive and provides a ~40% upgrade over the XP941.
 |
|||||||||
The line graph does reveal some anomalies, though. First it looks like the performance scales nicely, but after queue depth of two the performance actually degrades. I'm doing some thermal throttling tests later in the article and it's very likely that the read results are affected by that because I was able to reach 2250MB/s at queue depth of 32 with a cold drive (i.e. I went straight to QD32 without doing the scaling first that heats up the drive).
Sequential Write Performance
Sequential write testing differs from random testing in the sense that the LBA span is not limited. That's because sequential IOs don't fragment the drive, so the performance will be at its peak regardless.
Sequential performance is also great, but seems to be affected by thermal throttling even more. That said, I did reach over 1500MB/s with a cold drive.
 |
|||||||||
Facebook
Twitter
RSS
128 Comments
View All Comments
Laststop311 - Tuesday, February 24, 2015 - link
Also forgot to add really need the 1TB size because 25% OP is important to keep the drive fast 100% of the time.theduckofdeath - Tuesday, February 24, 2015 - link
Are you using your PC as the google.com web portal? :)Isn't 25% a bit excessive for a PC? I have 10% now and I can't really notice any difference from my previous install when I had around 15%....
philipma1957 - Saturday, February 28, 2015 - link
I agree with you as always ssd's are too small. I would love to get a 2tb ssd or even a 1.5tb ssdin pcie or 2.5 inch form factors. My needs are about 1.2tb space. I would like the 1 drive and just forget about it.
RazrLeaf - Tuesday, February 24, 2015 - link
So when is someone going to make a PCIe SSD with a black PCB? It sounds trivial, but it's pretty easy to fix. A green SSD would stuck out like a sore thumb on a motherboard with a black PCB.vLsL2VnDmWjoTByaVLxb - Tuesday, February 24, 2015 - link
Probably when greater than 1% of the market even cares.sablesg - Tuesday, February 24, 2015 - link
Plextor has a black edition of their M6e drive. Although I believe that comes with a pcie slot to M.2 adapter, and I'm not sure if they plan to sell just the drive alone.eanazag - Tuesday, February 24, 2015 - link
This is a PC OEM drive with the likelihood of it ending up in a laptop/tablet, so PCB color is not of high importance unless it is Apple. Apple PCBs are usually black.Expect something more visually appealing in retail versions.
I'd be more interested in thermal pads or heat spreaders for this drive.
cm2187 - Tuesday, February 24, 2015 - link
Personally I will NOT buy this until the engraving on the chips are using the font Courrier.bigboxes - Wednesday, February 25, 2015 - link
Brav-freakin'-oMykeM - Tuesday, February 24, 2015 - link
You can get the original SSD part from Apple via iFixit. It's not cheap but it comes with black PCB (because Apple uses back PCB on MBP logic boards):https://www.ifixit.com/Store/Mac/MacBook-Pro-13-In...