Comment by vladvasiliu
2 years ago
I think it's important to be able to have a rough idea of how you'd be using this. If this drop in performance means I could use a cheaper drive, I'm all for it.
But some drives are truly awful. My work laptop came with a cheap Samsung drive that would quickly drop to around 200 MB/s. At first, I thought I had somehow badly configured Linux or something (I'm running zfs with native encryption).
Then I went and checked my desktop running quite worn-out SATA ssds from ~2012 (840 evo) and those drives would wipe the floor with the NVMe in write performance. They wouldn't go below 400 something MB/s until almost full. Same kernel version and zfs config.
It would seem that this is quite common behavior in cheap drives. But I guess that if all you do is browse the web, write mails in outlook and type the occasional word document, you're still ahead of spinning rust for the durability (it won't break if you drop your laptop) and for the latency.
In my use case I'm talking about arrays of them, think 8. RAID can parallelize platter really nicely in that configuration. But on modern ram/cpu (epyc 9654s), you'll still see the disk dragging you down. NVME drags me down more.
Maybe the key is a bunch of small ones. Like 20 512GB modules... That may be brilliant. It's way cheap
Or just get some Kioxia CD8 or CD8R or similar from Samsung/ Solidigm/ Micron depending on what you need. It will be much faster than spinning rust in all situations I am quite sure. Decent SSDs have a huge latency advantage compared to even the best HDDs just out of principle. Enterprise SSDs focused on read-write workloads can sustain decent performance even under continuous 100% load. For example: https://apac.kioxia.com/en-apac/business/ssd/data-center-ssd...
For an example of an SSD review that shows a sustained write test:
https://www.tomshardware.com/reviews/samsung-980-m2-nvme-ssd... (https://cdn.mos.cms.futurecdn.net/mzdXcBUJUuxkbYfmQigqQE-970...)
In a 900 second timeframe, the 980 Pro drops down to a bit above 1GB/s, while the worst is somewhere in the tens of MB/s. So there are significant differences in SSD performance profiles which you can only find out about from reviews like this.
Similar results here:
https://www.anandtech.com/show/16504/the-samsung-ssd-980-500...
This was the kind of review I was talking about. But you should also look at the specific capacity you're after. IIRC for the 980 non pro the 1 TB is better than the smaller ones.
That sounds like you might be having quite specific needs. Some reviews have graphs showing how the drives behave in various situations, so that could help you.
However, what I've found perusing those reviews is that there's a huge price gap between this class of drives (9x0 pro, wd 8xx and the like) and "enterprise" drives which seem to have more stable performance.
Right. I'm just an unemployed guy with expensive hobbies