The Samsung SSD 850 EVO mSATA/M.2 Review
by Kristian Vättö on March 31, 2015 10:00 AM ESTMixed Random Read/Write Performance
Mixed read/write tests are also a new addition to our test suite. In real world applications a significant portion of workloads are mixed, meaning that there are both read and write IOs. Our Storage Bench benchmarks already illustrate mixed workloads by being based on actual real world IO traces, but until now we haven't had a proper synthetic way to measure mixed performance.
The benchmark is divided into two tests. The first one tests mixed performance with 4KB random IOs at six different read/write distributions starting at 100% reads and adding 20% of writes in each phase. Because we are dealing with a mixed workload that contains reads, the drive is first filled with 128KB sequential data to ensure valid results. Similarly, because the IO pattern is random, I've limited the LBA span to 16GB to ensure that the results aren't affected by IO consistency. The queue depth of the 4KB random test is three.
Again, for the sake of readability, I provide both an average based bar graph as well as a line graph with the full data on it. The bar graph represents an average of all six read/write distribution data rates for quick comparison, whereas the line graph includes a separate data point for each tested distribution.
Mixed random performance appears to be brilliant and power consumption is moderate too.
The 850 EVO has a typical curve at 250GB and above where the performance more or less stays constant until hitting 100% writes where it jumps up considerably. Only the 850 Pro breaks this trend as its performance in fact decreases as the share of writes is increased.
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Mixed Sequential Read/Write Performance
The sequential mixed workload tests are also tested with a full drive, but I've not limited the LBA range as that's not needed with sequential data patterns. The queue depth for the tests is one.
In mixed sequential workload the 850 EVO is good, but not overwhelming.
The 850 EVO's "bathtub" curve is a bit different from others' in the sense that the drop in performance is smooth rather than being sudden right after adding reads/writes to the mix.
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WackyDan - Saturday, April 4, 2015 - link
Eh... Nope. These won't work in the ThinkPads.blanarahul - Tuesday, March 31, 2015 - link
Hopefully, this drive will put an end to the mSATA/M.2 versions of the 840 non-EVO that companies are shipping in their laptops.Samus - Tuesday, March 31, 2015 - link
DoH! I just paid $20 more for the M550 (basically the MX100) 512GB M2 drive, which is double-sided and needs to be crammed into my laptop :\kgh00007 - Tuesday, March 31, 2015 - link
Hey, is there any chance you could fill one of these m.2 drives with data, power it off for a month then check the read speeds when you power it back on?I need some sort of evidence that this TLC V-nand does not have the same issues as the TLC in the 840 EVO.
Otherwise I'm not going to be able to buy one of these!
Cheers!
goodyes - Wednesday, April 1, 2015 - link
What the hell does not the charts compares with 840 ev msata ? Bad numbers Why not true sequential test ??And this site posting SUCKS, Why in the world I cannot use my facebook or so login, Did you know about disquss ? Get out the absurd captcha that fucking me 30 times or so trying to get a magical potion to know what the words saying,. THIS IS NOT ADVANCE IN TECH THIS IS TRASH
Kristian Vättö - Wednesday, April 1, 2015 - link
This is the third review with the new 2015 SSD Suite and I've only had limited time to test drives, hence the lack of 840 EVO in the graphs.goodyes - Wednesday, April 1, 2015 - link
Ya, but results that I have a 1TB 840 msata and write sequential at more than 500MBps around 520max MBps, and now I see than new 850 msata tops at ?? 480MBps ?? cannot be possible what my eyes look, AND WHY THE HELL NO ONE REVIEWER COMPARE With olders 840 msata, so I must think that all of you guys are a paid reviewers and you get money from samsung, if not, YOU MUST compare to older modelcgorange - Wednesday, April 1, 2015 - link
Other than providing samples, I can assure you that Samsung doesn't pay Anandtech to review its productsEkitrak - Wednesday, April 1, 2015 - link
The Final Words page has 2 entries of "Samsung 840 EVO mSATA" on the Amazon Price Comparison. I'm guessing this is an error and one of them is supposed to be the Sata III version?Kristian Vättö - Wednesday, April 1, 2015 - link
I'm not seeing this -- maybe you accidentally mixed up the 850 EVO mSATA and 840 EVO mSATA as they are both in the table (or maybe this was already fixed by another editor).