20110618, 15:26  #1 
Jun 2011
2_{8} Posts 
CPU @ 100%
Just installed GIMP, and as soon as I started the program, my cpu maxed out. I restarted, and it maxed out again. Opened my process manager, and GIMP was using between 4996%. I understood that it would not affect my performance very much, however with the CPU maxed, I can't do much. I closed the program, and my CPU dropped down to about 10%.
So what do I need to do? 
20110618, 16:18  #2  
Bamboozled!
"๐บ๐๐ท๐ท๐ญ"
May 2003
Down not across
2^{2}·3·941 Posts 
Quote:
My machines spend virtually their entire life running at 100% CPU and yet hardly ever does it impinge on interactive work. Paul Last fiddled with by xilman on 20110618 at 16:19 Reason: Fix minor typo 

20110618, 17:16  #3 
6809 > 6502
"""""""""""""""""""
Aug 2003
101ร103 Posts
10100100010000_{2} Posts 
Yes, this is normal and it is fine.
The Prime95 program only fills in the gaps when nothing else is running. As you saw, when it is not running typically between 9095% of the CPU time is wasted, Prime95 only takes that time. As you noted, you saw 49%96%. The first was likely while Prime95 had started a thread on 1 core and was waiting to start it on another. And since Paul neglected to say it, "Welcome to the world of Prime Crunching". 
20110618, 17:26  #4 
Jun 2011
10_{2} Posts 
Thanks guys, I just misread the info. At this rate I'll find a prime in no time.

20110620, 01:24  #5 
"Richard B. Woods"
Aug 2002
Wisconsin USA
2^{2}·3·641 Posts 
I think that if you'd actually tried doing something (word processing, browsing, whatever...), instead of only looking at the CPUbusy meter, you would have found that you could actually do whatever you wanted to do.

20110620, 02:45  #6 
Dec 2010
Monticello
5×359 Posts 
More likely you will find a nonprime in no time...the collective primecrunchers have been looking for Mersenne Prime #48 (which may or may not be the 48th Mersenne Prime) for a couple years now...but nonetheless, good luck!

20110620, 08:11  #7 
Jun 2003
7·167 Posts 
His chances of finding a prime are quite good: most found factors are prime.

20110702, 19:58  #8  
Jun 2011
Henlopen Acres, Delaware
133_{10} Posts 
Quote:
Very funny, and equally true. I think the OP meant "Mersenne Prime" though. If you look at the total GHzdays reported on the Mersenne.org page, and divide that by 13 (the number of them found by GIMPS) that's the average GHzdays per prime. Put your own GHzdays in the numerator, and that number in the denominator, and that is roughly your odds of finding a Mersenne. 

20110702, 21:23  #9  
"Brian"
Jul 2007
The Netherlands
2·3·5·109 Posts 
Quote:
A sizeable proportion of that total GHzdays will be factoring worktypes which would not in themselves discover a Mersenne Prime, or double checking which would be extremely unlikely to (never has so far). So obviously your worktype is very important: it needs to be LL and highly preferably firsttime testing. And the LLwork which is being done now is on much larger numbers than in the early days of GIMPS, and these numbers require far more GHzdays to test, plus it's also reasonable to assume that the Mersenne Primes will be more sparsely distributed in this current working zone: so the LLwork now will discover far fewer primes relative to GHzdays than the early work did. 

20110703, 00:11  #10  
Jun 2011
Henlopen Acres, Delaware
10000101_{2} Posts 
Quote:


20110703, 02:40  #11 
Dec 2010
Monticello
703_{16} Posts 
Yep, core #4 is, however, doing something important: Making sure that the first LL test indeed correctly reported that the exponent was a composite. There's a slight (probably worse than 1 in a million) chance that an exponent was incorrectly reported as composite  it both has to be prime, and the first LL test has to have incorrectly reported it was composite.
P1 is also good work for a CPU; I'm finding factors on average in significantly fewer GHz days than it would take to do two LL tests. You just have to give it a lot (a Gigabyte or so) of memory. 