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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mapesdhs - Wednesday, August 8, 2018 - link
If you have quite literally "valuable info" then don't use a consumer SSD at all. Heck, damn the speed, you're far better with even a used 840 Pro. That's why I obtained one for this build I did, along with an SM951 for a scratch video drive:http://www.sgidepot.co.uk/misc/charitypc1.html
BurntMyBacon - Wednesday, August 8, 2018 - link
First point of interest is always have a backup plan. If information is valuable, don't rely on any single copy of it.As to your question of endurance, I don't think most personal use cases are likely to have an issue. If you have a professional workload, get a professional drive. The 840 Pro that mapesdhs keeps evangelizing is actually a pretty good option, though a Pro series (MLC) nvme drive will provide better performance while still providing endurance is the same ballpark as the 840Pro.
As to whether it will refresh the cell if powered on, I would expect most Samsung drive will, though it is not known whether
BurntMyBacon - Wednesday, August 8, 2018 - link
As to whether it will refresh if powered on, I don't believe that Samsung flash required the refresh cycle once the moved to 3D NAND with a larger feature size. That said, since QLC halves the voltage swing (and corresponding charge) vs TLC, it is likely that Samsung will need to do something to prevent voltage drift. This may not necessarily require active refreshing, though. It is not known (by me) whether this is a requirement for other manufacturer's 3DQLC NAND either.BurntMyBacon - Wednesday, August 8, 2018 - link
I get why they don't want an edit feature, but would it really hurt if they added a time limited recall type edit feature for when you fat thumb a hot key that posts your unfinished message before you are done with it. Maybe give you five minutes after a post initiate the edit to catch typos or grammar issues. It wouldn't really be enough to alter a conversation as it is unlikely that others will have responded within this time frame.AbRASiON - Tuesday, August 7, 2018 - link
Considering the abysmal performance of this thing, I think you really need a $/GB chart on the page and it would be nice to put in a very fast, modern hard drive. Something huge and 7200RPM with a lot of cache on it.Just to put it in perspective, because as it stands, wow this thing looks terrible. I expect VERY cheap prices if they're gonna run like this.
Oxford Guy - Tuesday, August 7, 2018 - link
No matter how terrible QLC is it is going to succeed in the market because consumers respond well to big and cheap.So, I think one interesting question is going to be how much disguising there will be of products having QLC. Microcenter, for instance, is apparently selling a TLC Inland drive, calling it MLC.
piroroadkill - Wednesday, August 8, 2018 - link
That's how I want QLC drives to be compared - to the best hard drives people might actually buy today to store their games on, for example.I'd love a cheap and large 4TB drive for my games, but it has to be both much faster than the HDD setup I use for games (2× 2TB 3.5" Seagate Hybrid drives in RAID0) and not too far off the same price.
zodiacfml - Wednesday, August 8, 2018 - link
Impressive performance. Easily beats my SATA 850 EVO in performance and twice the capacity I bought last December for the same price.There should be no reason for notebook manufacturers to settle for HDD except the cheapest laptops.
mapesdhs - Wednesday, August 8, 2018 - link
Given the 850 EVO's strong reliability reputation though, I wouldn't be overly eager to recommend this new QLC model for anyone wanting a decent degree of confidence that their data is safe. But then, most consumers don't have backup strategies anyway. :DSpunjji - Wednesday, August 8, 2018 - link
If you want safe data, make regular backups. Anything else is a false sense of security!