"Memory allocation error"

[JuanTutors]

I actually have four sticks of single-channel 1GB RAM stick. I upgraded from four sticks of dual-channel 512K RAM.

[Mr. P-1]

Originally Posted by dominicanpapi82

I actually have four sticks of single-channel 1GB RAM stick. I upgraded from four sticks of dual-channel 512K RAM.

I'd still recommend doing 'before' and 'after' benchmarks. The gain you get from using more than about 500MB during P-1 stage 2 for normal exponents is minimal. Also if you're going to be spending the bulk of your processing time doing LLs, any loss of memory speed will apply all the time, dwarfing the slight gain you might get during the 1% or thereabouts of the time you spend doing P-1 stage 2.

It might be different if you intend to more than incidental P-1 work, or if you're testing huge exponents.

[harlee]

Originally Posted by Prime95

No. Are you using 25.8? It is linked with the /LARGEADDRESSAWARE option that lets prime95 access more memory under Windows.

Is that option only for 64-bit version or does it work with 32-bit? What about 25.9?

[Prime95]

Originally Posted by harlee

Is that option only for 64-bit version or does it work with 32-bit? What about 25.9?

That option should allow 32-bit prime95 to access 3GB instead of 2GB. All versions after 25.8 will be linked with that switch.

[JuanTutors]

Originally Posted by Prime95

That option should allow 32-bit prime95 to access 3GB instead of 2GB. All versions after 25.8 will be linked with that switch.

Is there something I can do to access 3GB now?

[harlee]

Originally Posted by Prime95

That option should allow 32-bit prime95 to access 3GB instead of 2GB. All versions after 25.8 will be linked with that switch.

Ok, then we might have a problem. Earlier I had set the amount to memory to 1792 MB but when P-1 Stage 2 started it got the memory error and went to approx 1400ish. My system is running Windows XP SP3 with 2.5GB of memory (2 X 1GB chips and 2 x 256 MB chips). I'm currently in the middle of stage 2, do you want me to up the memory now to see what happens or wait for the next P-1 assignment to change the memory settings?

[jasonp]

Unless you boot with the /3GB switch, 1400MB of memory is about the most that a single win32 process can reasonably allocate for itself. At least I haven't seen one allocate more than that, the theoretical limit is 2GB.

[JuanTutors]

So is there a way to get the software to allocate more memory than the 1100/1300 MB that it went down to?

[harlee]

On my 32-bit system, I normally run 1536MB for P-1 testing and I don't get any memory allocation errors.

[JuanTutors]

I just tried using two threads to do P-1 tests on two different exponents. No dice. It says "Out of memory!", which it's NOT. I can't even get my ram usage past 2GB with prime95!!

[Mr. P-1]

Originally Posted by harlee

On my 32-bit system, I normally run 1536MB for P-1 testing...

I used to use that exact same amount.

There's no reason to use a binary-round number. If you want to optimise your memory allocation, look at the number of relative primes processed each pass, and make sure that you never have a small number left over for the final pass.