3 ms·
In my experience, depends on the SSD. Consumer grade ones appear really fast because they have a DRAM cache, and as soon as you start having a bunch of cache-mi
by exabrial 4y ago
In my experience, depends on the SSD. Consumer grade ones appear really fast because they have a DRAM cache, and as soon as you start having a bunch of cache-misses you realize how slow they actually are.
We got a bunch of enterprise grade Samsung SSDs and there'a large difference in sustained I/O. It's not "instant" by any means, but it there are other things slowing I/O.
- zamadatix 4y agoOnly the very best drives hit >200 MB/s in 4k write (even with DRAM as cache) and for 4k mixed not even Optane drives get that high.
- wtallis 4y agoDid you forget to stipulate that you're only talking about workloads that issue IO requests serially with zero parallelism?
- zamadatix 4y agoNo, I just didn't pick QD32T8 to pump the numbers either. Even in such workloads the gap to sequential speed is a decent ratio, just not painfully so as in most other mid to singular workloads.