actualy to save on CPU usage so that there is no lag, all random data should be pregenerated.
In what regard?
Not sure that I follow.
There isn't much random IO in real life but there is some and thats why we are adding a small portion of random I/O. (on top of small file I/O)
I have 3 alternating buffers so It's generally not an issue.
1.5GB/s was what I measured using a small array on the Areca 1880.
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Hardware:
Well, let's say (just for the explanation) that your random generator can produce 100MB/s. X25-M can also do 100MB/s of sequential.
As a result, since (if I understood you correctly) they are done in the same thread, without backbuffering, the resuling write speed would be 50MB/s.
If you get that overall speed, then X25-M is writing sequential data and not random I/O.
It looks like you generate the random data in a separate thread then, so I misunderstood. I don't see how the entire system (as in the CPU/memory/PCI-e even) would be able to sustain those speeds.I have 3 alternating buffers so It's generally not an issue.
1.5GB/s was what I measured using a small array on the Areca 1880.
What happens past the write instruction issued at the device level? Will the SSD controller not try to fill a complete block whenever possible to minimise read/ relocate/ write penalties?
Presumably it would try to avoid 4K writes being scattered across the span of the drive. Isn't that what Intel refer to ask write combining?
Would it also try to rotate locations of writes for wear levelling?
Just asking as I don't really know![]()
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