Hit Rate stays at about 0%

[iamnemo]

Hi everyone ! New user here

I'm trying to configure PrimoCache on one of my recording studio PCs.
I need fast READ access to large sample libraries files (2GB+) on volume A below.
The data (4TB so far) is mostly static. Putting everything on SSDs is overkill for now.

Here's my config :


Disks are organized as :


with volumes:


Volume A is a soft-RAID 0 (Win Striped) volume composed of 9 x 1TB disks.

I can dedicate 8GB for L1 and two SSDs (2x256GB) CacheD1 & CacheD2 for L2.

I tried READ (only) caching volume A with Primo with the following configs :

1) L1 + L2 (my first choice)

2) L1 only

3) L2 only in diff configs :
- two SSDs in spanning mode (476GB)
- two SSDs in striping (faster) mode (476GB)
- both SSDs separately (solo)

Tried all the above with block size values going from min 16KB to max. value. No difference.

My test is to load 2GB of samples from A in some sample player then close it.
Repeat these steps 5 times and see hit rate.

In ALL cases above the Cache Hit Rate stays at 0%.

What's going on here ? I would expect a hit rate close to 100% after 5 attempts.

N.B. : I did also reset the win perf counters as instructed https://blogs.technet.microsoft.com/yon ... ver2008r2/. No diff.

Out of ideas... Please help ! Thanks !
Iam

[minhgi]

it would help if you could include screenshot of primocache

[iamnemo]

Hi Minhgi. Thanks for replying. My situation seems to have improved a bit :


The low hit rate seems to be caused by Windows' own caching system using the free ram available (here about 42GB).
I should check again when ram usage is around 90% or so.
When I do I will report here.

[minhgi]

I make the explanation short and simple. If your 2+GB libraries contain large files, for instants a 512MB file, Primocache may cache only a 200MB of the 512MB and drop the rest since there no need large sequential. I have seem Primocache cache my karaoke video / CDG files, range from 1MB - 300 MB, in a sample of 5TB samples. Either, Primocache is hard coded to limit the size or just favor small smaller data. You experience will vary depending drive setup and intended usage. If you use Primocache the way it was made for, small random dataset, you will get very high hit rates.

I have great experiences getting 90+ hit rate most of the time. Anyway, it seem your L2 Storage have cached 72GB out of 244GB. You may need to access the same dataset in order to get the higher hit rate.

Support team may have better explanation since it is their software.

[iamnemo]

Still waiting for the hit rate to increase. For the moment most of the re-reads are from Windows cache.