Tiered L2 Cache

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Tiered L2 Cache

Post by JimieSitu »

I can't be the only one with this scenario:
I'm replacing my old system drive SSD with a fancy new super-fast NVMe SSD.

I'd like to be able to use a couple GB of the NVMe as a quasi L1 Cache and use my old SATA SSD as my L2 cache. There's a factor 5 in read/write speed and IOPS between the two, after all.

Unfortunately, PrimoCache as it is now doesn't seem to support this functionality.
Last edited by JimieSitu on Mon May 17, 2021 4:12 am, edited 2 times in total.
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Re: Tiered L2 Cache

Post by Jaga »

If your NVMe is replacing your C: drive (currently the old SSD), then there are no other physical tiers of caching you can use against it other than actual RAM as a L1. The rule of thumb is: never cache a SSD with another SSD, unless it is magnitudes faster. i.e. you could cache your old SSD with a portion of the NVMe, but the gains would only be marginal overall.

You didn't mention if you were trying to cache a spinner drive (non-SSD) with either, so it's hard to figure out your true goals in this scenario. Either way, only one SSD would suffice as a L2 cache if you were - your assumption that there is no tiered L2 caching is correct.

You'd also never want to use a portion of a drive to cache the rest of the drive (i.e. a couple GB from the NVMe to cache the rest of it), as it would cause significant slowdowns.
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