PrimoCache device driver slowing down SSD copy...

[Oxymoron]

Hello All !!!

Basically, with no PrimoCache, if I copy a large file between 2 SSD (7000/5000MB), it's done at 4GB/s... Pretty nice
If I Install PrimoCache, with no cache the transfer is done at 2.5GB/s.
Is it a CPU bound issue, or something else ?
How to fix ?

Thank you.

[Support]

You mean the problem occurs even if no cache task is created? This seems weird. If no caching is set up, PrimoCache should not affect the speed at all. If you have time, can you make a simple video to show us this problem? Thank you.

[Stateless]

I've noticed something similar. If you pause the caching for a volume the performance is TERRIBLE, like drive "active time" during a benchmark is ~60% and throughput is ~50% of what I would expect. If I remove the volume from the cache task the performance is significantly better, but slower than with PC uninstalled.

Dell PERC H730P Mini, 12 x Seagate Exos X22 w/ writeback cache enabled

Without PC installed my HDTune Benchmarks are:
Read (Sequential): 1791734 MB/s
Write (Sequential): 2757495 MB/s
Read 4KB Random Single: 74 IOPS
Write 4KB Random Single: 4104 IOPS
Read 4KB Random Multi: 2915 IOPS
Write 4KB Random Multi: 1256 IOPS

With PC installed, no cache task:
Read (Sequential): 774918 MB/s
Write (Sequential): 1406633 MB/s
Read 4KB Random Single: 70 IOPS
Write 4KB Random Single: 3833 IOPS
Read 4KB Random Multi: 2750 IOPS
Write 4KB Random Multi: 815 IOPS

With PC installed, no cache task (2nd run):
Read (Sequential): 773539 MB/s
Write (Sequential): 1428149 MB/s
Read 4KB Random Single: 78 IOPS
Write 4KB Random Single: 3607 IOPS
Read 4KB Random Multi: 1583 IOPS
Write 4KB Random Multi: 799 IOPS

This is a NUMA system with the NUMA aware option enabled.

[Support]

Without PC installed my HDTune Benchmarks are:
Read (Sequential): 1791734 MB/s
Write (Sequential): 2757495 MB/s

With PC installed, no cache task:
Read (Sequential): 774918 MB/s
Write (Sequential): 1406633 MB/s

This looks like a huge performance difference..., quite weird. We will check this.

[Stateless]

If it helps, I'm using the HDTune file benchmark, 32GB file size to exhaust the cache on the H730P, random data pattern.

[Support]

If it helps, I'm using the HDTune file benchmark, 32GB file size to exhaust the cache on the H730P, random data pattern.

Thanks for the information.

[Stateless]

I've done some extensive testing on another server.

I was unable to reproduce the performance difference.

It took me a while, but eventually I realized that the difference between the test server and the production server is that the production server was using BitLocker

I created a volume without enabling BitLocker and performance was as expected when not added to a cache task.

I don't know if this relates to OPs use case, but I certainly retract my previous statements about performance issues relating to PrimoCache. Sorry

[Support]

That explains why there was a huge performance difference. Many thanks!

[sparks79]

PrimoCache might be messing with your speeds due to its own overhead. Double-check those settings and monitor your CPU usage during transfers. Also, your SSDs might not be jiving well with extra caching.

[marybrainsome]

Facing the same issue...