L2 slow write speeds

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0ldman
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L2 slow write speeds

Post by 0ldman »

I've got a Ryzen 3700x, 32GB of DDR4 3200, 12GB L1, Samsung PM961 256GB NVME caching various drives.

My write speed on the NVME drive is only ~30MB/s, rarely even as high as 50MB/s, when fetching data for the cache drive.

I thought maybe it was an issue with TRIM so I removed it as the L2, formatted the drive, set it as a data drive, tested it and got ~1GB/s write speeds. I set it up as L2 again and I'm only getting ~30MB/s write speeds filling the cache. It takes nearly 6 times as long to cache Cyberpunk as it does to load it from the hard drive in the first place. Once it's loaded to L2 it's fast, of course.

Why does it take so long to fill L2 and what can I do to improve this?

Edit: finally, literally just now after a couple of weeks of fiddling with this, it writes @ 300MB/s. No idea what's going on here.
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Re: L2 slow write speeds

Post by Support »

By default, PrimoCache populates data into L2 when your system is idle. So if your system keeps busy, the speed of L2 population will be slow. You may tune the speed and set the value to "Fastest" or "Instant" in the L2 Advanced Settings - Gather Interval.
0ldman
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Re: L2 slow write speeds

Post by 0ldman »

Bringing back a zombie thread but it's the same issue still a couple of years later.

Whether I'm using readfile alone to scan in the files or just letting Primocache handle it normally, doesn't matter what the gather interval is set to, the write speed is a fraction of the read speed of the host drive. My WD Red 4TB 5400RPM drive can read at 200MB/s in bursts, pretty consistently runs around 150MB/s, monitoring, not testing, so it isn't being held back by the drive. Without Primocache write speeds to the NVME cache drive are 1GB/s.

If it is something in Primocache that is trying to not overload the system, lower performance, that makes sense but it needs to be something we can adjust on our end.
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Re: L2 slow write speeds

Post by Support »

Could you please upload a screenshot of you cache configuration and stats for our reference by following the guidance in the link below?
https://kb.romexsoftware.com/en-us/2-pr ... leshooting
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