The Samsung PM981 SSD Review (512GB, 1TB): Next Generation Controller And 3D NAND
by Billy Tallis on November 30, 2017 9:02 AM ESTSequential Read Performance
Our first test of sequential read performance uses short bursts of 128MB, issued as 128kB operations with no queuing. The test averages performance across eight bursts for a total of 1GB of data transferred from a drive containing 16GB of data. Between each burst the drive is given enough idle time to keep the overall duty cycle at 20%.
The burst sequential read performance of the Samsung PM981 doesn't quite set a new record, but it's pretty close to the top performer and very far ahead of any non-Samsung drive.
Our test of sustained sequential reads uses queue depths from 1 to 32, with the performance and power scores computed as the average of QD1, QD2 and QD4. Each queue depth is tested for up to one minute or 32GB transferred, from a drive containing 64GB of data.
On the longer test with higher queue depths, the best MLC-based drives pull ahead of the PM981 and even the 960 EVO has a slight advantage.
 |
|||||||||
The 1TB PM981 starts out with almost the same performance as the 1TB 960 EVO, but the PM981's performance falls off a bit during the first half of the test while the 960 EVO remains steady. The 512GB PM981 doesn't experience any slowdown, but it is slower than the 1TB model throughout the test.
Sequential Write Performance
Our test of sequential write burst performance is structured identically to the sequential read burst performance test save for the direction of the data transfer. Each burst writes 128MB as 128kB operations issued at QD1, for a total of 1GB of data written to a drive containing 16GB of data.
The PM981s both deliver the same record-setting burst sequential write performance that is a marked improvement over the best of Samsung's last generation, and far ahead of any competing flash-based SSD.
Our test of sustained sequential writes is structured identically to our sustained sequential read test, save for the direction of the data transfers. Queue depths range from 1 to 32 and each queue depth is tested for up to one minute or 32GB, followed by up to one minute of idle time for the drive to cool off and perform garbage collection. The test is confined to a 64GB span of the drive.
On the longer sequential write test, the 512GB PM981 falls behind most of the rest of the Samsung drives but the 1TB model remains on top, ahead of even the 960 PROs.
 |
|||||||||
The 1TB PM981 hits full write speed at QD2 and stays there for the rest of the test, holding on to its lead over the 960 PRO. The 512GB PM981 runs out of SLC write cache early on and its performance bounces around with the garbage collection cycles.
Facebook
Twitter
RSS
53 Comments
View All Comments
tsk2k - Thursday, November 30, 2017 - link
It's all about that 3D-Xpoint nowadays.rsandru - Thursday, November 30, 2017 - link
Speaking of which, can we have the Optane 900p data points back in?boeush - Thursday, November 30, 2017 - link
Hmm, yeah - all about 1 TB 3D XPoint - how much would that cost, again, and what's the retail availability of the M2 form-factor?ddriver - Thursday, November 30, 2017 - link
Unfortunate after so many years of complete domination samsung is not even trying anymore. It will be TLC all over in order to squeeze out every cent worth of profit from that advantage.Spunjji - Thursday, November 30, 2017 - link
"...the PM981 has caught up to or surpassed the MLC-based 96x drives on many tests, setting new records not just for TLC-based drives but for client SSDs as a whole."Right; they're clearly not trying at all. :|
mapesdhs - Thursday, November 30, 2017 - link
"...in order to squeeze out every cent worth of profit from that advantage."That's called business. If rivals don't like it, they should make something better and bring it to market. I might not like how Samsung has managed its pricing, etc., but if I were them, then based on fiduciary duty to shareholders I would do exactly the same thing.
ddriver - Thursday, November 30, 2017 - link
They are not, but it requires north of a simpleton's way of looking at it to see it. Because they could have kept MLC and offered a significant boost in performance thought the entire drive.And the claim that using TLC it catches up on MLC drives is just nonsense. There is no engineering miracle here. There is simple caching at play, the drive doesn't touch TLC for the duration of AT's flimsy test suite. Once the drive runs out of cache performance quickly gets abysmal - about 750 mb/s once it gets to the point of using TLC directly. Not to mention the reduced endurance.
Granted most casual consumers won't be doing anything as data intensive, but many prosumers will, which means that current consumer grade drives are no longer adequate for prosumer applications, which wasn't the case with the previous generation, indicating that samsung is indeed taking a step back.
And things are not looking too well in the more affordable enterprise range neither, its lousy with TLC as well. Meaning that samsungs devolution now forces prosumers to shop for the much more expensive high-end enterprise storage solutions.
I don't mind TLC. What I mind is depriving the market of MLC. I didn't mind paying the MLC premium for the 960 PRO over the EVO. It was a good deal. I mind that they are taking that deal away from the market. And if you had 2 properly working brain cells you'd mind that too.
MFinn3333 - Thursday, November 30, 2017 - link
"There is simple caching at play, the drive doesn't touch TLC for the duration of AT's flimsy test suite."What? Here is the destroyer benchmark's description...
Total GB Read: 1583.02 GB
Total GB Written: 875.62 GB
Total IO Operations: 49.8 million
Queue depth is 50% 1 depth.
What is your definition of flimsy?
mkaibear - Friday, December 1, 2017 - link
This is deedee, his definition of "flimsy" is "if there is any possible way in which I can be right, then I meant that".ddrіver - Thursday, November 30, 2017 - link
Exactly. The products are better because time passes on and technology advances, not because they are actually struggling to make them better. Profit is their number one concern performance just happens to increase from time to time...