Constant 5.35% cache hit rate

[amirfoox]

I'm using Primocache 9.1, set the caching to Read only to both my 256GB SSD and my 500GB HDD and dedicated 7500 MB of RAM (out of my 16GB) to the caching strategy, then restarted and ran a few read tests.

I've noticed that no matter what I try, the Cache Hit Rate remains a constant 5.35% and never goes higher, even when I'm running application and games several times in a row. What seems to be the problem?

The Level-1 Cache states: 7500 (VM) and the overhead is set to: 827.21MB.

Fancycache had 50%-70% Cache Hit Rate in my setup.

I'm on Win 8-64 bit, 16GB RAM.

Thanks for any help!

By the way, although I've set the caching strategy to Read only, it mentions in the main window that my strategy is set to Read/Write, might be worth looking into.

Edit: I don't know if it's relevant, but I've just noticed that similarly to this topic: viewtopic.php?f=33&t=2192 I'm caching a Samsung 830 256GB, block size 4K and LFU-R, although I don't use Write-Defer.

[InquiringMind]

Amirfoox,

Could you test using a disk benchmarking utility (like Crystal Diskmark) and see if the figure changes? (it should show 100% while Crystal Diskmark is doing its read tests).

[amirfoox]

When using Crystal Diskmark, the caching stands at 98.44% and the sequential read speeds reflect that and reach 4900-5000.

Weird behavior: even after closing the Crystal Diskmark, the Cache Hit Rate remains on 98.44% and the graph remains high even when nothing is being read.

I'll reboot and see if that changes.

Edit: after reboot the Cache Hit Rate fluctuates between 6.7% and 9.50% at most. I tried running applications and games in window mode 3-4 times in a row and the Cache Hit Rate remains doesn't move and now settles on 9.30%.

[Support]

Please see here for the definitions of hit rate. Statistics is made since the computer bootup and reset at next boot.
http://www.romexsoftware.com/en-us/prim ... mance.html

[amirfoox]

Please don't read just the last line, that's the whole problem - the Hit Rate percentage never goes up in regular usage, long after reboot. It only goes up in the artificial Crystal benchmark.

What's the point of having a caching application if it doesn't seem to actually cache and load data from cache in standard usage?

[amirfoox]

Update: it does go up slowly every day. Now the Hit Rate stands on 20%, so I guess I should just give it time.

[InquiringMind]

When I last checked, my Hit Rate was a little under 35% (about 5GB allocated). Primo Cache's hit rate seems to be measured over a longer term than FancyCache's, which may explain the different figures reported (and a good thing too, since FC seemed to only measure the last 5-10 seconds). Ultimately though, the rate will depend on how often data is reread/rewritten - using different applications all the time will reduce the benefits any caching can offer.