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Re: Caching Options for Downloads Drive
Posted: Tue Jul 02, 2019 2:46 pm
by hshah
Decided to up the L2 to 16GB because I have the space. There hasn't been much activity today because I am tinkering with other things, but here is the current view.
Is what I have set for the block size, deferred write and prefetch etc. appropriate? The block size defaulted to 32KB but the drive's cluster size is 4KB. If I change it to 4KB PrimoCache estimates a 2.32GB memory overhead, vs the 297MB at 32KB. Is it worth changing it to something in between?

- Annotation 2019-07-02 154228.png (23.57 KiB) Viewed 16494 times
Re: Caching Options for Downloads Drive
Posted: Tue Jul 02, 2019 5:30 pm
by ferrari
I would do 16KB block size, and format the hard disk to 16KB cluster size if possible. Not super important though for a downloads cache. I just use whatever keeps the overhead below 1GB of ram because at that point you're just losing performance from not being able to dedicate that ram to L1 cache.
Re: Caching Options for Downloads Drive
Posted: Tue Jul 02, 2019 6:19 pm
by hshah
Cool, changed it to 16KB and it says the overhead is 594MB
When you say format the disk, you mean the 2TB one? If so, don't have the capacity elsewhere to dump the data whilst I do that lol. I may do in a month or two, so could do it then

Re: Caching Options for Downloads Drive
Posted: Tue Jul 02, 2019 7:45 pm
by ferrari
Yeah the 2TB one. Not that important for your setup though because I doubt the L2 cache will have much work to do for you. With matched block/cluster size I find ssd L2 cache performance to be 95% of native ssd performance, with a bigger block size than cluster size speed drops to maybe 85% of native ssd performance.
Re: Caching Options for Downloads Drive
Posted: Tue Jul 02, 2019 10:23 pm
by hshah
Hmm, I have just rebooted my PC and whilst the cache task is there, the drive isn't present underneath it

Re: Caching Options for Downloads Drive
Posted: Wed Jul 03, 2019 7:40 am
by ferrari
Haven't had that happen do you have fastboot enabled?
Re: Caching Options for Downloads Drive
Posted: Wed Jul 03, 2019 12:58 pm
by hshah
ferrari wrote: ↑Wed Jul 03, 2019 7:40 am
Haven't had that happen do you have fastboot enabled?
Nope, it is disabled. I added the volume back in, rebooted a few times since and it has stayed, so no idea what happened.
Re: Caching Options for Downloads Drive
Posted: Wed Jul 03, 2019 2:18 pm
by Support
I think in your case you may just set L2 cache 100% read in order to prevent too much wear by write caching. If the D drive is only used for downloading, then I think 8GB RAM is enough and L2 cache is not necessary.
Re: Caching Options for Downloads Drive
Posted: Thu Jul 04, 2019 3:25 am
by ferrari
hshah wrote: ↑Tue Jul 02, 2019 10:23 pm
Hmm, I have just rebooted my PC and whilst the cache task is there, the drive isn't present underneath it
Just happened to me as well after I installed the latest 1903 windows update, maybe that was your problem too?