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Old 2013-09-07, 00:19   #34
chalsall
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"Chris Halsall"
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Quote:
Originally Posted by Prime95 View Post
Anyone have any ideas for me to look into before the CPU upgrade? If not, I'm writing this bug off as unfixable / unexplained.
You wouldn't dare!!!

Quote:
Originally Posted by Isaac Asimov
The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' (I found it!) but 'That's funny ...'
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Old 2013-09-07, 00:27   #35
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Maybe George is going to invent magic faerie dust that turns logical cores into physical cores.
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Old 2013-09-07, 00:47   #36
chalsall
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Quote:
Originally Posted by TheMawn View Post
Maybe George is going to invent magic faerie dust that turns logical cores into physical cores.
I was thinking somewhat along the lines that this can't possibly be an intractable problem...

Many of us own a great deal of hardware.

Many of us are rather good with software.

The fundamental question is what experiments have to be run to solve the problem.
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Old 2013-09-07, 01:33   #37
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Backing out here. I'm out of my depth as an AMD operator.

Last fiddled with by kladner on 2013-09-07 at 01:38 Reason: running off at the mouth
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Old 2013-09-07, 04:05   #38
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Monitor individual core usage until your iteration times increase.

If four cores are maxed and four are idle and the cores being used change, then you've got the program suddenly changing the core assignment... for some reason. I'm a Windows guy and not a programmer, so don't ask me why. Hah!

If you don't have four maxed and four idle cores, then take a screenshot of the usage history and try to match up peaks and valleys. The ones that match up will be the two logical cores which form the physical core. I've seen that before. Again, this is the core assignment doing its thing but switching between logical cores... for some reason. I'm a Windows guy and not a ...
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Old 2013-09-07, 16:44   #39
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On Linux /proc/cpuinfo should tell you everything you need to know about what CPUs are in the box. On the one hyperthreaded system I have the "core id" says which real core the processor maps to.

I'm about to update my factMsieve.pl to use fivemack's way to check how many processors a box has:
my $NUM_CPUS=`grep -c MHz /proc/cpuinfo`; # Linux only!

Which will reduce the number of versions of the script I need (some systems only vary in the number of CPUs).

Chris
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