P-1 factoring anyone?

[joblack]

Originally Posted by Prime95

In the new scheme of things, if P-1 doesn't get done then when an exponent is assigned to an LL tester he must do the P-1, last 2 levels of TF, and then the LL test.

In my opinion it doesn't matter. I had these processess with bigger exponents and it finished in a day or two.

[petrw1]

Originally Posted by Sunfish

Core 2 Duo T7700 @ 2.4 GHz:
Memory: 1024MB RAM at day and 1280 MB RAM at night time
Expo: 50M range

Stage 1: 17.2 hrs + Stage 2: 8.2 hrs = Total: 25.4 hrs

Stage 2 is really running fast on this platform, amazingly fast compared to the posted data on other Duo and Quad processors.

It seems odd that your Stage 2 is faster than Stage 1. I have done P-1 on several PC's, though all Intel anywhere from PIV 2.4 up to Q9550 Quad-2.87. My Stage 2 time is always about 50% longer than Stage 1.

However, I did find that 1 core of my Core2 Duo E6550 (2.3 Ghz) was slightly faster than 1 core of my Q9550 (2.87 Ghz) with other cores doing 28M LL in both cases. 50 vs 52 hours with 800Mb RAM.

[cheesehead]

Originally Posted by petrw1

It seems odd that your Stage 2 is faster than Stage 1.

Let's all note that such comparisons, to make any sense, must always include the specific B1 and B2 bounds!!

Any statement about stage 2 times that omits the B1/B2 bounds, or, at the very least, what multiple B2 is of B1, is meaningless.

E.g.: If B1=500000, B2=600000 (1.2 * B1), then stage 2 will always take (much) less time than stage 1.
If B1=500000, B2=900000000 (1800 * B1), then stage 2 will always take (much) more time than stage 1.

My Stage 2 time is always about 50% longer than Stage 1.

... and your B2 is always about what multiple of B1, so that we can attach some meaning to that 50% figure ??

[ET_]

Originally Posted by cheesehead

Let's all note that such comparisons, to make any sense, must always include the specific B1 and B2 bounds!!

Any statement about stage 2 times that omits the B1/B2 bounds, or, at the very least, what multiple B2 is of B1, is meaningless.

E.g.: If B1=500000, B2=600000 (1.2 * B1), then stage 2 will always take (much) less time than stage 1.
If B1=500000, B2=900000000 (1800 * B1), then stage 2 will always take (much) more time than stage 1 (at least, for any practical RAM size I can imagine we're using).

... and your B2 is always about what multiple of B1, so that we can make some sense of that 50% figure ??

I guess B2 = 100*B1...

Luigi

[cheesehead]

Originally Posted by ET_

I guess B2 = 100*B1...

... so if we're in a context where everyone knows that's the default and not mentioning it just means it wasn't overridden, that's fine!

But that's not here: prime95's B1/B2-choosing algorithm doesn't use B2 = 100*B1.

(Which P-1 software uses that default? I know I've read threads about it, but can't recall just now.)

[ET_]

Originally Posted by cheesehead

... so if we're in a context where everyone knows that's the default and not mentioning it just means it wasn't overridden, that's fine!

But that's not here: prime95's B1/B2-choosing algorithm doesn't use B2 = 100*B1.

(Which P-1 software uses that default? I know I've read threads about it, but can't recall just now.)

Prime95 in ECM mode?

Luigi

[cheesehead]

Originally Posted by ET_

Prime95 in ECM mode?

I asked about P-1 software.

[axn]

Originally Posted by cheesehead

(Which P-1 software uses that default? I know I've read threads about it, but can't recall just now.)

Ummm.. Prime95 > Advanced > P-1 (just leave B2=0)

[cheesehead]

Originally Posted by axn

Ummm.. Prime95 > Advanced > P-1 (just leave B2=0)

http://mersenneforum.org/showpost.ph...2&postcount=43

[Sunfish]

Originally Posted by James Heinrich

If you could send me a benchmark for your T7700 for my throughput calculator I'd appreciate it.

Finally had a chance to collect some benchmark data. Took a bit longer than expected as these are extremely busy days. Anyway, you should have them by now.

[petrw1]

In order for the project to declare an exponent to be "adequately" P1'd is there a minimum required B1 or B2 limit?

For example on the low end:
Exponent 59123023 B1/B2 = 2048 / 16384

On the other extreme I see:
Exponent 33500153 B1/B2 = 11025000 / 882000000

My assignments with 600-1200 RAM with exponents in the 50M range have B1 / B2 of about: 605000 / 16788750

In this extreme my B1/B2 are 147 and 1024 times the small end while the biggest is 18 and 52 times bigger than my B1/B2.