mprime checking available memory

tha · 2015-12-03, 20:20

I installed 4GB in a machine and configured mprime to use 3072 of it. I then replaced the 4GB with 2GB and forgot to reconfigure mprime. Oddly mprime keeps on running and does not seem to notice the total amount has changed. It starts the second stage of P-1 work with the parameters that you would expect for 4GB, and does not protest along the way.

chalsall · 2015-12-03, 22:00

Quote:

Originally Posted by tha

It starts the second stage of P-1 work with the parameters that you would expect for 4GB, and does not protest along the way.

Can anyone say "swap" or "thrash"?

Madpoo · 2015-12-04, 02:43

Quote:

Originally Posted by chalsall

Can anyone say "swap" or "thrash"?

Although, it depends on the work being done and how much actual RAM mprime needs.

I'd want to know what exponent and what bounds were being used, then see exactly how much memory that process is snarfing up.

If it is more than the free RAM, yeah, thrashing is an understatement. Seems like it would beat your system within an inch of it's life.

Prime95 · 2015-12-04, 03:05

Looking at the source code: mprime will ask the OS for the amount of physical ram. If your day or night mem settings are greater than the amount of physical RAM, then that setting is reduced to "physical RAM - 8MB".

Of course, I imagine this would still thrash.

I cannot explain why the P-1 stage 2 bounds would be unaffected.

science_man_88 · 2015-12-04, 12:35

the only thought that came to my mind is that with multiple channels 2GB could equate to more than 4GB.

Dubslow · 2015-12-04, 16:48

Quote:

Originally Posted by science_man_88

the only thought that came to my mind is that with multiple channels 2GB could equate to more than 4GB.

Are you serious?

science_man_88 · 2015-12-04, 18:11

Quote:

Originally Posted by Dubslow

Are you serious?

I didn't say I was smart at these things

KuruFun · 2015-12-07, 15:56

I think you have to test the performance of your computer ...

2015-12-03, 20:20	#1
tha Dec 2002 881 Posts	mprime checking available memory I installed 4GB in a machine and configured mprime to use 3072 of it. I then replaced the 4GB with 2GB and forgot to reconfigure mprime. Oddly mprime keeps on running and does not seem to notice the total amount has changed. It starts the second stage of P-1 work with the parameters that you would expect for 4GB, and does not protest along the way.

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2015-12-04, 03:05	#4
Prime95 P90 years forever! Aug 2002 Yeehaw, FL 17·487 Posts	Looking at the source code: mprime will ask the OS for the amount of physical ram. If your day or night mem settings are greater than the amount of physical RAM, then that setting is reduced to "physical RAM - 8MB". Of course, I imagine this would still thrash. I cannot explain why the P-1 stage 2 bounds would be unaffected.

2015-12-04, 12:35	#5
science_man_88 "Forget I exist" Jul 2009 Dartmouth NS 8461₁₀ Posts	the only thought that came to my mind is that with multiple channels 2GB could equate to more than 4GB.

2015-12-07, 15:56	#8
KuruFun Dec 2015 1 Posts	I think you have to test the performance of your computer ...