Does "checkpoint frequency" affects folding speed alot?

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Does "checkpoint frequency" affects folding speed alot?

Postby Nantes » Sat Jan 21, 2012 3:43 pm

Hi guys, I would like to know the impact of various "checkpoint frequency" settings on folding speed. Right now I have checkpoints set every 10 min because I sometimes have to restart the computer, but is this limiting folding speed alot? How long does creating a checkpoint stop folding for? Thanks.
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Re: Does "checkpoint frequency" affects folding speed alot?

Postby Jesse_V » Sat Jan 21, 2012 4:53 pm

Checkpoint frequency should have minimal effect on folding speed. I don't think it takes any significant time to write to the HD, and it might even be done in parallel, but I'm not positive about that. When you restart F@h, it picks up from the last checkpoint, which is either every 10 minutes, and some cores checkpoint every 1%, so it could be both. So on one hand you'd want to have a frequent checkpoint frequency so that you dont lose a lot of work, but on the other hand having a super-fequent checkpoint could increase your chances of checkpoint corruption if something happens during the write process. If the checkpoint becomes corrupted,the WU starts over from the beginning. I'd say 15 minutes is a fairly good number, which is the default.
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Re: Does "checkpoint frequency" affects folding speed alot?

Postby MtM » Sun Jan 22, 2012 1:59 am

Gpu cores checkpoint at every completed frame, since the tpf can be as low as a minute it would mean you'd loose allot of progress if would only checkpoint every 15m and the core isn't exited cleanly.

If you have a slot gpu, like my hd4350, with tpf above the 15m, it doesn't even create a checkpoint at the set interval ->

Image

From my own evidence and afaik in general, this settings is ignored by the client for all gpu slots :?:

Edit: replaced image with thumbnail :oops:
Last edited by MtM on Sun Jan 22, 2012 2:07 am, edited 1 time in total.
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Re: Does "checkpoint frequency" affects folding speed alot?

Postby bruce » Sun Jan 22, 2012 2:05 am

MtM wrote:Gpu cores checkpoint at every completed frame, since the tpf can be as low as a minute it would mean you'd loose allot of progress if would only checkpoint every 15m and the core isn't exited cleanly.

If you have a slot gpu, like my hd4350, with tpf above the 15m, it doesn't even create a checkpoint at the set interval ->


True. I consider it a bug in the GPU cores. They should add a timered checkpoint in any frame that's longer than 15 minutes.
They're not going to fix it in FahCore_11.
Does anybody know if it's a problem in FahCore_16?
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Re: Does "checkpoint frequency" affects folding speed alot?

Postby MtM » Sun Jan 22, 2012 2:16 am

I'm not even sure it is a problem if it happens with FAHCore_16 as I don't know if the core has any logic in it which checks when the last checkpoint was created. Would create a new problem if the core writes a checkpoint at 15m interval while the tpf is 15m and 30s causing checkpoints being created for both events.

I don't think it would be hard to add a variable holding the datetime stamp of the last checkpoint, so it would be limited to the maximum checkpoint interval ( eg 00:17:32:WU00:FS00:Completed 3% -> checkpoint, 00:32:32 same progress = create checkpoint -> :00:18:32:WU00:FS00:Completed 4% -> no checkpoint ) :?:
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Re: Does "checkpoint frequency" affects folding speed alot?

Postby bruce » Sun Jan 22, 2012 2:53 am

MtM wrote:I'm not even sure it is a problem if it happens with FAHCore_16 as I don't know if the core has any logic in it which checks when the last checkpoint was created. Would create a new problem if the core writes a checkpoint at 15m interval while the tpf is 15m and 30s causing checkpoints being created for both events.

I don't think it would be hard to add a variable holding the datetime stamp of the last checkpoint, so it would be limited to the maximum checkpoint interval ( eg 00:17:32:WU00:FS00:Completed 3% -> checkpoint, 00:32:32 same progress = create checkpoint -> :00:18:32:WU00:FS00:Completed 4% -> no checkpoint ) :?:


Some cores will checkpoint at 15:00 and again at 15:30. Others will not.
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Re: Does "checkpoint frequency" affects folding speed alot?

Postby MtM » Tue Jan 24, 2012 11:57 am

bruce wrote:
MtM wrote:Gpu cores checkpoint at every completed frame, since the tpf can be as low as a minute it would mean you'd loose allot of progress if would only checkpoint every 15m and the core isn't exited cleanly.

If you have a slot gpu, like my hd4350, with tpf above the 15m, it doesn't even create a checkpoint at the set interval ->


True. I consider it a bug in the GPU cores. They should add a timered checkpoint in any frame that's longer than 15 minutes.
They're not going to fix it in FahCore_11.
Does anybody know if it's a problem in FahCore_16?


Nice edit, wasn't there when I replied :)
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