On the SSD side we have DRAMless and TLC.
The annoying thing is that unless the government forces disclosure, the honest manufacturers are the ones hurt, having to start advertising "no SMR!" to differentiate, like the organic/health food products in the grocery store that have to list all the poisons they don't have.
I'm happy to buy a DRAMless + TLC SSD for my boot disk on my web browsing PC (not development), it is a reasonable compromise for a lower price. Same for SMR drives, I won't have problems with them as backup disks.
I think the problem here is SMR drives are sold without disclosure, and it has already created some serious problems in practice.
> What’s worse, they’re shipping DM-SMR drives as “RAID” and “NAS” drives This is causing MAJOR problems – such as the latest iteration of WD REDs (WDx0EFAX replacing WDx0EFRX) being unable to be used for rebuilding RAID[56] or ZFS RAIDZ sets: They rebuiild for a while (1-2 hours), then throw errors and get kicked out of the set.
I don't doubt it, but do you have the source for that? I read stories about people using the Seagate Archive disks in RAIDZ and it worked fine for them.
This has accelerated my move to enterprise 16TB drives, because I really don't want to expose myself to data loss on rebuilds taking hugely extended times.
This also means you'll need a lot more HD's per RAID set to guard against multiple failures during rebuild. Which means that even the supposed data density/space advantage of SMR is moot - you'd be better off with PMR.
* Western Digital admits 2TB-6TB WD Red NAS drives use shingled magnetic recording
https://blocksandfiles.com/2020/04/14/wd-red-nas-drives-shin...
Also, "boost the main muggle"? I usually think I know my Potter references, but this one escapes me.
TLC and QLC are misnomers, a TLC cell holds 3 bits but has eight levels and QLC likewise 4 bits with 16 levels. You get a multiplicative increase in capacity for an exponential decrease in reliability. The manufacturers have been very obfuscatory with the marketing, since they know the inconvenient truth.
Does anyone still make a reasonably large (>100GB) SSD with good old 100K SLC? I have a 64MB (true 2^26 bytes capacity!) flash drive with 100K SLC; 0 bad blocks when it was new, and still 0 bad blocks a decade and a half later despite plenty of abuse.
To go a bit further, I'm amazed you don't see a drive manufacturer offering an enterprise-client "firmware builder" tool, or at least as a build-to-order service if you're a big enough client. I could see customers that wanted to respec their 1TB drives as, say, 750GB to ensure an abundance of over-capacity for reallocation later, or the YOLO "I'm gonna run the cheapest drives in RAID0" crowd slashing overprovisioning and getting 1050Gb out of the same unit. If you dialed down the capacity low enough, the drive could presumably stay in "use SLC mode only" mode for its entire duration.
I'm amazed you don't see a drive manufacturer offering an enterprise-client "firmware builder" tool, or at least as a build-to-order service if you're a big enough client.
If they do, you probably wouldn't hear about it --- and I suspect they do, given that there are things like this: https://superuser.com/questions/593303/hitachi-hard-drive-wi...
Are you sure you're not talking about QLC? Current TLC drives can be pretty decent in terms of write speed and endurance.
Some workloads will never have a problem, others will hit performance walls.
Of course, for NAS RAID arrays that were already saturated by TLC man times over, it makes little difference.
Depending on how you define average, yes. But a sufficiently bursty workload is always writing to SLC. How the drive performs in practice depends on where you sit on that spectrum.
Explaining: there are 100% TLC drives high in the benchmarks, as long as you look at 1tb+ category.
You only need 3 times more chips with TLC than MLC, which was still easily doable, and there were no equivalent sized MLC chips anyways.
Read speeds weren't a problem with any flash technology, but QLC will give you harddrive level read speeds at sizes below 1tb.
QLC will only take off in SSD's sized 5TB+ if per-chip speed will not improve dramatically, like at least twofold.
QLC + huge cache is not good deal cost wise in comparison to pure TLC.
Speed-wise no, but it (almost) keeps up with the lower end of TLC NVMe drives.
> QLC + huge cache is not good deal cost wise in comparison to pure TLC.
Cost wise? Yes it seems to, Sabrent's "Rocket Q" is about the cheapest 2TB on the market, and performs pretty well, Reads more or less competitively with the non-QLC drives from the same vendor and writes at around 2/3 the speed.
Intel's 660p range performs a little less well, but typically still multiple times as fast as SATA drives, and is generally cheaper too.
I've tried QLC drives for cheap cluster storage. It turns out one QLC drive was slower than 4 old HDDs. I had to go back to HDDs until I switched to TLC flash because they were faster. Tail latencies hitting one second on QLC. It's incredible how bad they are. We shouldn't even be calling them SSDs at that point, they don't even remotely live up to the performance expectations you might have from an SSD.
This doesn't come out in tests or consumer experience of the drives that have a significant cache, like the aforementioned "Rocket Q", which has a DRAM cache and a large SLC/TLC cache behind it.
Cluster storage is not a mainstream consumer use.
> We shouldn't even be calling them SSDs at that point
Is the intel 660p range not an SSD? It significantly outperforms SATA SSDs.
Was that a consumer QLC drive with SLC cache or an enterprise QLC drive with no cache and firmware that actually cares about latency? Something like the Micron 5210 ION enterprise QLC drive should still have at least 20x the sustained random write performance of a single hard drive.