The Intel SSD 660p SSD Review: QLC NAND Arrives For Consumer SSDs
by Billy Tallis on August 7, 2018 11:00 AM ESTAnandTech Storage Bench - Light
Our Light storage test has relatively more sequential accesses and lower queue depths than The Destroyer or the Heavy test, and it's by far the shortest test overall. It's based largely on applications that aren't highly dependent on storage performance, so this is a test more of application launch times and file load times. This test can be seen as the sum of all the little delays in daily usage, but with the idle times trimmed to 25ms it takes less than half an hour to run. Details of the Light test can be found here. As with the ATSB Heavy test, this test is run with the drive both freshly erased and empty, and after filling the drive with sequential writes.
As with the Heavy test, the SLC cache of the Intel SSD 660p is extremely beneficial and brings the average data rate of the 660p up into high-end NVMe territory. When the drive is full and the SLC cache has been reduced to its minimum size, performance suffers and drops below the Crucial MX500 mainstream SATA drive but not all the way down to the level of the Toshiba RC100 DRAMless NVMe SSD.
The best-case latency scores from a freshly-erased 660p are acceptable for a high-end NVMe SSD and excellent for an entry-level drive. In the worst case of a full drive, the average latency is far higher but still low enough that the drive won't actually feel much slower. The 99th percentile latency climbs very high by SSD standards, but is still barely up into the average latency range of hard drives.
On the Light test, the average read latency of the 660p stays comfortably below that of SATA drives even for the worst-case full drive test run, and only the average write latency shows a serious problem from filling up the whole drive and not giving it enough time to empty the now-reduced SLC cache.
The full-drive 99th percentile write latency of the 660p on the Light test is almost as bad as the 600p or the Toshiba RC100. Otherwise, the 660p doesn't have any worrying QoS problems on this test and users won't notice serious pauses from the drive.
The energy usage of the 660p on the Light test is below most other NVMe drives when the test is run on an empty drive, and even with the extra background work and longer test duration of the full-drive test run the 660p is only a little less efficient than the average for this bunch of NVMe SSDs.
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StrangerGuy - Tuesday, August 7, 2018 - link
"I am a TRUE PROFESSIONAL who can't pay more endurance for my EXTREME SSD WORKLOADS by either from my employer or by myself, I'm the poor 0.01% who is being oppressed by QLC!"Oxford Guy - Tuesday, August 7, 2018 - link
Memes didn't make the IBM Deathstar drives fun and games.StrangerGuy - Tuesday, August 7, 2018 - link
I'm sure you were the true prophetic one warning us about those crappy those 75GXPs before they were released, oh wait.I'm sorry why are you here and why should anyone listen to you again?
Oxford Guy - Tuesday, August 7, 2018 - link
Memes and trolling may be entertaining but this isn't really the place for it.jjj - Tuesday, August 7, 2018 - link
Not bad, at least for now when there are no QLC competitors.The pressure QLC will put on HDDs is gonna be interesting too.
damianrobertjones - Tuesday, August 7, 2018 - link
These drives will fill the bottom end... allowing the mid and high tiers to increase in price. Usual.Valantar - Wednesday, August 8, 2018 - link
Only if the performance difference is large enough to make them worth it - which it isn't, at least in this case. While the advent of TLC did push MLC prices up (mainly due to reduced production and sales volume), it seems unlikely for the same to happen here, as these drives aim for a market segment that has so far been largely unoccupied. (It's also worth mentioning here that silicon prices have been rising for quite a while, and also affects this.) There are a few TLC drives in the same segment, but those are also quite bad. This, on the other hand, competes with faster drives unless you fill it or the SLC cache. In other words, higher-end drives will have to either aim for customers with heavier workloads (which might imply higher prices, but would also mean optimizations for non-consumer usage scenarios) or push prices lower to compete.romrunning - Wednesday, August 8, 2018 - link
Well, QLC will slowly push out TLC, which was already pushing out MLC. It's not just pushing the prices of MLC/TLC up, mfgs are slowing phasing those lines out entirely. So even if I want a specific type, I may not be able to purchase it in consumerspace (maybe enterprise, with the resultant price hit).I hate that we're getting lower-performing items for the cheaper price - I'd rather get higher-performing at cheaper prices! :)
rpg1966 - Tuesday, August 7, 2018 - link
"In the past year, the deployment of 64-layer 3D NAND flash has allowed almost all of the SSD industry to adopt three bit per cell TLC flash"What does this mean? n-layer NAND isn't a requirement for TLC is it?
Ryan Smith - Tuesday, August 7, 2018 - link
3D NAND is not a requirement for TLC. However most of the 32/48 layer processes weren't very good, resulting in poorly performing TLC NAND. The 64 layer stuff has turned out much better, finally making TLC viable from all manufacturers.