Full Boot Drive into RAM?

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steveb
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Full Boot Drive into RAM?

Post by steveb »

Hello,

Is it possible to configure Primo Cache to load 100% of the drive into RAM? Basically, making the main OS a ram drive with differed write back to NVMe storage.

Currently was planning to look at getting using an Intel P5800X but noticed lower Q1 read speeds on AMD hardware and wanted to explore all options.
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Re: Full Boot Drive into RAM?

Post by Support »

No setting to force PrimoCache loading all data to the cache. It only caches the data when they are read, or via the prefetch function.
steveb
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Re: Full Boot Drive into RAM?

Post by steveb »

If i had say 200GB boot drive with 200GB L1 Cache (prefetch enabled) and read all the data. Should i expect to keep having 100% hit rate?

Also, is there any performance difference between "Keep L1 cache on fast shutdown" and "prefetch start at windows boot" ?
InquiringMind
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Re: Full Boot Drive into RAM?

Post by InquiringMind »

Steveb,

For storing a whole volume in RAM, Primo Ramdisk would probably be a better choice. You can run it alongside PrimoCache.
steveb
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Re: Full Boot Drive into RAM?

Post by steveb »

InquiringMind wrote: Mon Sep 20, 2021 10:41 am Steveb,

For storing a whole volume in RAM, Primo Ramdisk would probably be a better choice. You can run it alongside PrimoCache.
From my understanding currently its not possible to load Primo Ramdisk drivers as part of the Windows install process.
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Re: Full Boot Drive into RAM?

Post by Support »

steveb wrote: Sat Sep 18, 2021 10:02 am If i had say 200GB boot drive with 200GB L1 Cache (prefetch enabled) and read all the data. Should i expect to keep having 100% hit rate?
Not tested. But theoretically, it will not be 100% but will increase and close to 100%. During the boot phase, some data has to be read from disks because at that time prefetch hasn't started yet.
steveb wrote: Sat Sep 18, 2021 10:02 am Also, is there any performance difference between "Keep L1 cache on fast shutdown" and "prefetch start at windows boot" ?
They are different things. "Keep L1 cache on fast shutdown" means that L1 cache is not cleared at the fast shutdown. So when the computer boot from the fast shutdown state, Windows will automatically loads the L1 cache and no prefetch is needed here. The price is that additional shutdown time and boot time are needed.
The option "prefetch start at windows boot" is to start the prefetch earlier during the normal Windows boot.
steveb
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Re: Full Boot Drive into RAM?

Post by steveb »

Support wrote: Tue Sep 21, 2021 1:09 pm
steveb wrote: Sat Sep 18, 2021 10:02 am If i had say 200GB boot drive with 200GB L1 Cache (prefetch enabled) and read all the data. Should i expect to keep having 100% hit rate?
Not tested. But theoretically, it will not be 100% but will increase and close to 100%. During the boot phase, some data has to be read from disks because at that time prefetch hasn't started yet.
steveb wrote: Sat Sep 18, 2021 10:02 am Also, is there any performance difference between "Keep L1 cache on fast shutdown" and "prefetch start at windows boot" ?
They are different things. "Keep L1 cache on fast shutdown" means that L1 cache is not cleared at the fast shutdown. So when the computer boot from the fast shutdown state, Windows will automatically loads the L1 cache and no prefetch is needed here. The price is that additional shutdown time and boot time are needed.
The option "prefetch start at windows boot" is to start the prefetch earlier during the normal Windows boot.
Thank you for the information.
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