Excessive write activity on L2 cache with defer-write disabled

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munchbit
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Excessive write activity on L2 cache with defer-write disabled

Post by munchbit »

I set up an my laptop's SSD to cache the HDD which contains the OS. I intend to only cache reads, so I left defer-write disabled. However, when Steam downloads or updates games, the disk activity on the SSD shoots up to 100% according to task manager. I didn't expect this as I expected PrimoCache to only cache reads, not writes. I assume it's doing writethrough caching, right? Which means data writes to both SSD and HDD. Due to space constraints, the SSD heats up and throttles, which sharply increases response latency and makes it slower than the HDD. I've noticed if I set up individual read/write cache space, and put 100% of the capacity for reads, all writes go to HDD now, which is what I wanted. Now, the laptop behaves better under heavy writes.

I just want to ask about the caching behavior when defer-write is disabled. Does PrimoCache cache recently written data when defer-write is disabled? And that setting individual read/write cache space to 100% for reads disables this behaviour?
Babel17
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Re: Excessive write activity on L2 cache with defer-write disabled

Post by Babel17 »

Steam might be reading what was downloaded to ensure it wasn't corrupted.
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Re: Excessive write activity on L2 cache with defer-write disabled

Post by Support »

Please check following document.
https://kb.romexsoftware.com/en-us/2-pr ... ache-space

For L2 cache, "100% read" is set by default if you don't enable Defer-Write.
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