Syzygy on RAM Drive

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yorkman
Posts: 105
Joined: Thu Jul 27, 2017 8:59 pm

Re: Syzygy on RAM Drive

Post by yorkman » Tue Apr 28, 2020 4:13 pm

MikeB wrote:
Thu Jan 16, 2020 12:49 am
yorkman wrote:
Tue Jan 14, 2020 5:45 pm
Is it possible to store my 3 syzygy paths in ram on Windows, such as Win'2012 R2? I'm currently using Syzygy from SSD.

If it's possible, how do I do it? If it matters my gui is Aquarium.
it can be done, but one has to consider how much RAM they have. 6 man syzygy takes 195GB , so if you have 512GB of ram , no problem. If you have 16Gb RAM , just let the OS take care of it.

PS the long hyphen is now the new nine on this board.
Thanks. So it goes into ram automatically, whatever fits. In my case it'll be 256 GB ram so it should all fit, but that leaves 106 GB for the OS and engine hash (full 6 men syzygy is 150GB) or is it shared with the hash? Just wondering what size hash I can set in that case.

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MikeB
Posts: 4640
Joined: Thu Mar 09, 2006 5:34 am
Location: Pen Argyl, Pennsylvania

Re: Syzygy on RAM Drive

Post by MikeB » Tue Apr 28, 2020 6:29 pm

yorkman wrote:
Tue Apr 28, 2020 4:13 pm
MikeB wrote:
Thu Jan 16, 2020 12:49 am
yorkman wrote:
Tue Jan 14, 2020 5:45 pm
Is it possible to store my 3 syzygy paths in ram on Windows, such as Win'2012 R2? I'm currently using Syzygy from SSD.

If it's possible, how do I do it? If it matters my gui is Aquarium.
it can be done, but one has to consider how much RAM they have. 6 man syzygy takes 195GB , so if you have 512GB of ram , no problem. If you have 16Gb RAM , just let the OS take care of it.

PS the long hyphen is now the new nine on this board.
Thanks. So it goes into ram automatically, whatever fits. In my case it'll be 256 GB ram so it should all fit, but that leaves 106 GB for the OS and engine hash (full 6 men syzygy is 150GB) or is it shared with the hash? Just wondering what size hash I can set in that case.
Knowing that you will doing deep analysis on an EPYC server , you will want to max out hash at 128GB and just let the OS figure out which TB to cache to memory. Hash using large pages will best serve by using multiples of 2048MB . You might want to test out different configurations. I have a NVMe PCI that reads nearly at 3500 MB/s, so I really dont worry about it. It is what it is. You might be better off using 192MB hash for deep analysis. You will be surprised how quickly 128 cores will fill up 128 GB of hash - it will be just a few minutes really.
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yorkman
Posts: 105
Joined: Thu Jul 27, 2017 8:59 pm

Re: Syzygy on RAM Drive

Post by yorkman » Thu Nov 26, 2020 9:12 pm

Wow. Hard to believe I haven't been on here since April. Yes, this is what I've always been doing. I always set my hash to 131071 MB. And I too use NVMe PCI.

Dann Corbit
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Location: Redmond, WA USA
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Re: Syzygy on RAM Drive

Post by Dann Corbit » Mon Nov 30, 2020 6:58 pm

I use a gumstick (m.2) PCIE4.0 SSD and those rascals run like the wind.
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