Best settings for cache?

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Myg
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Best settings for cache?

Post by Myg »

Hi, I have 64GB of RAM on my Laptop, 32GB of which I have allocated to PrimoCache. I am not using L2 (SSD,HDD) at all, just L1 (Pure RAM). What would be the best settings I could use to get the most out of the program?
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Jaga
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Re: Best settings for cache?

Post by Jaga »

Shared read/write space (not separate), deferred writes (~10 seconds, possibly 30 if your laptop is stable), 8K or 16K block size (a blend of performance and lower overhead), Pre-fetch at boot (if your C: drive is a SSD).
Myg
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Re: Best settings for cache?

Post by Myg »

Jaga wrote: Sun Jun 27, 2021 1:57 am Shared read/write space (not separate), deferred writes (~10 seconds, possibly 30 if your laptop is stable), 8K or 16K block size (a blend of performance and lower overhead), Pre-fetch at boot (if your C: drive is a SSD).
Thanks, but I am looking for the ultimate performance settings, no holds barred, no expense spared.
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Jaga
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Re: Best settings for cache?

Post by Jaga »

If you are certain your machine is rock solid stable, you can change deferred write times to ~10 minutes, and then block size to the same as your volume's cluster size (typically 4K on a SSD/NVMe).
Myg
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Re: Best settings for cache?

Post by Myg »

Jaga wrote: Sun Jun 27, 2021 5:10 pm If you are certain your machine is rock solid stable, you can change deferred write times to ~10 minutes, and then block size to the same as your volume's cluster size (typically 4K on a SSD/NVMe).
Thanks, I will try that. If anyone else has any other suggestions which might speed things up please share!
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Re: Best settings for cache?

Post by InquiringMind »

I would argue in favour of larger block sizes (smaller index = faster to search and you gain an element of pre-caching). Enabling Pre-Fetch makes a big difference if you reboot your system regularly.

Aside from that, PrimoCache is heavily influenced by memory performance. If you haven't done so, you may wish to check that the BIOS settings are optimised for performance (with XMP profiles enabled if appropriate). However pushing things too hard here can affect system stability and laptops aren't likely to offer the headroom that a desktop would.

And that does bring things nicely to my final point - if money is no object, get a desktop. Performance will be significantly better (desktops aren't constrained by low-power, low-heat requirements), far more upgrade options exist, and you can treat yourself to a large screen, surround speaker system and an arsenal of gaming peripherals (laptops may be able to accommodate some of these, but not without losing portability).
Myg
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Re: Best settings for cache?

Post by Myg »

Thanks for your input InquiringMind. Would an infinite Defer-Write latency be the optimal setting?
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Re: Best settings for cache?

Post by InquiringMind »

I've not noticed any significant benefit from extending Defer-Write beyond the default 10s myself and you do increase the risk of data loss with higher settings. If you're confident about your backup (and restore) regime, feel free to experiment.
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Jaga
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Re: Best settings for cache?

Post by Jaga »

InquiringMind wrote: Mon Jun 28, 2021 3:43 pm I've not noticed any significant benefit from extending Defer-Write beyond the default 10s myself and you do increase the risk of data loss with higher settings. If you're confident about your backup (and restore) regime, feel free to experiment.
I find better write coalescing and trimmed blocks the longer it is extended. Plus it turns more random writes into squential ones. But I rarely go over 10 minutes on deferred writes, unless it's for specialized use.
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Re: Best settings for cache?

Post by Myg »

Ok, I tried Prefetch and it crashed my PrimoCache UI completely. I couldn't load it up or access it in any way. I had to uninstall and re-install PrimoCache to get it working again. Not recommended.
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