Stage 2 Memory Settings

[gamer30]

Hey guys, I'm just wondering if there's any benefit to setting the memory quite high. I read the readme about it and I used to use:

Day: 512MB
Night: 1024MB

Since I have a lot of memory, I just changed it to:

Day: 2048MB
Night: 4096MB

Is there any benefit to this really? I currently have prime95 running 24 hours/day though I don't always let it run constantly, for instance, if I want to play a game.

Looking forward to your expert responses!

[Dubslow]

That's around the point where more memory becomes less and less useful. If you went up to say 4/6 GiB (instead of 2/4) then you might see a few % tops speed improvement, if that. OTOH, .5/1 will give you a 20%+ improvement over .25/.5. Thus 2/4 should be plenty.

Note, of course, that allocated memory only makes a difference for Stage 2 P-1 (not LL tests), but from the thread title, it seems you're aware of that.

[Xyzzy]

http://www.mersenneforum.org/showthr...16337&p=282335

[gamer30]

Originally Posted by Dubslow

That's around the point where more memory becomes less and less useful. If you went up to say 4/6 GiB (instead of 2/4) then you might see a few % tops speed improvement, if that. OTOH, .5/1 will give you a 20%+ improvement over .25/.5. Thus 2/4 should be plenty.

Note, of course, that allocated memory only makes a difference for Stage 2 P-1 (not LL tests), but from the thread title, it seems you're aware of that.

I actually don't know the difference or even really understand much of what is happening on primes95. I just plug it in, let GIMPS decide what it does (whichever makes more sense setting) and let it go. I just assumed running higher mem for the test was better. THe default is 8MB/8MB!

[axn]

Originally Posted by gamer30

Day: 2048MB
Night: 2048MB

It is probably better if you give the same amount to both day & night memory (even if that means lesser amount at night).

[gamer30]

Originally Posted by axn

It is probably better if you give the same amount to both day & night memory (even if that means lesser amount at night).

Alright, done. Also, I know this is off topic, but I ran a torture test for 8 hours without error, is that fair that my system is stable? (I know 24 hours is desirable, but I'd rather be running GIMPS.)

[Dubslow]

Originally Posted by gamer30

Alright, done. Also, I know this is off topic, but I ran a torture test for 8 hours without error, is that fair that my system is stable? (I know 24 hours is desirable, but I'd rather be running GIMPS.)

If you haven't fiddled with any of the hardware settings, then that's good enough.

[axn]

Originally Posted by gamer30

I ran a torture test for 8 hours without error, is that fair that my system is stable? (I know 24 hours is desirable, but I'd rather be running GIMPS.)

If you want to QA your system while still being productive, run a few doublechecks. That should tell you whether your system is "real world" stable, while still contributing to GIMPS.

[gamer30]

Originally Posted by axn

If you want to QA your system while still being productive, run a few doublechecks. That should tell you whether your system is "real world" stable, while still contributing to GIMPS.

I have OC'd it a bit. It seems as long as I don't fiddle too much it's stable. Probably motherboard isn't so great for OC. The doublechecks have me confused, because I disabled error reporting since it was coming up "poor" on the last OC run. When I last enabled round off error checking, I had no issues though I should keep it up longer I guess. I've been running GIMPS for nearly 24 hours without issues, though error checking is off (or disabled.)

[Dubslow]

Originally Posted by gamer30

I have OC'd it a bit. It seems as long as I don't fiddle too much it's stable. Probably motherboard isn't so great for OC. The doublechecks have me confused, because I disabled error reporting since it was coming up "poor" on the last OC run. When I last enabled round off error checking, I had no issues though I should keep it up longer I guess. I've been running GIMPS for nearly 24 hours without issues, though error checking is off (or disabled.)

Double checking meaning the GIMPS worktype of LL testing exponents that have already been tested once.

It's good for "real stability testing" because unlike first-time LL, with the DC there's a first residue you can compare yours against. Around 90-95% of the time, your residue should match the first test. (If you can't achieve that success rate, then you've probably pushed the OC too far.)

[gamer30]

Originally Posted by Dubslow

Double checking meaning the GIMPS worktype of LL testing exponents that have already been tested once.

It's good for "real stability testing" because unlike first-time LL, with the DC there's a first residue you can compare yours against. Around 90-95% of the time, your residue should match the first test. (If you can't achieve that success rate, then you've probably pushed the OC too far.)

Pardon me, but I find this confusing. You are talking about enabling "round off checking" and "SUM(INPUTS) error checking" while running GIMPS right?

Currently the "round off" checking is coming up "Round off: 0.0000000000 to 0.xxxxxxxxxx"

Is this normal?