[QUOTE=axn;226305]But why do a variable search in the first place? Can't the search be parameterised so that it does a fixed amount of work (modulo the use of randomness in the search space)? Ideally speaking, the amount of work (not time) to be expended is a function on the amount of work to be expended on the other phases (sieving, LA, etc.) -- why should having a faster CPU or GPU cause me to do a deeper search?[/QUOTE]

I wish I knew how to predict how long the search would take, so that searching a single leading algebraic coefficient would take a reasonable time. pol5 doesn't have this problem because its search space is really quite small; Kleinjung's improved algorithm has a drastically larger limit, but the larger limit is what finds good hits, so you don't want to severely constrain it just to something you can exhaustively search. Under those circumstances it makes more sense to me to just search as far as you can in a fixed fraction of the total sieving time.

[quote=jasonp;226275]If you want to enforce a hard deadline, you can add '-d X' to the command line and msieve will interrupt itself after X wall-clock minutes.[/quote]
Unfortunately, that would entail modifying Aliqueit and then trying to figure out the X for each sample. And, it's not a hard deadline I'm concerned about. I'm wondering why the polynomial selection doesn't finish on this machine.

This is the only machine that is displaying this. I'm wondering why, since this CPU is a whole GHz faster than the one it replaced. At this point I'm actually wondering if it will ever quit. What is it really trying to reach and why should I bother to run ggnfs on this machine if the polynomial selection alone takes longer than SIQS? It's now been running polynomials for over 12 hours for a c99. My 1.8GHz machine never took this long and this is a 2.8GHz Pentium 4 with a 1M cache?

If this is still running polynomials when I shut it down tonight, I will run Aliqueit with "gnfs_cutoff = 100" tomorrow and see how long it takes to factor via SIQS.

Perhaps someone can help me understand CPU hours:

I'm assuming in this case, msieve is calculating the 0.33 hour relative to my CPU and therefore hasn't anything to do with the CPU speed, but simply percentage of use and time in use.

If msieve is using ~84% of the CPU when I check it with the system monitor, which itself is using ~12%, and the CPU is running at 100% when observed, I should be able to mathematically estimate completion of 0.33 CPU hours:

Roughly, if I shut down the monitor, I should gain ~12%CPU. I expect this goes to msieve, since it is running normal priority and all by itself. This means a conservative estimate for msieve is >90% of a 100% tasked CPU.

Therefore 1 clock hour * .9 = .9 CPU hour.

Shouldn't msieve have reached 0.33 CPU hour long ago? It's been 12.5+ clock hours. Is that not 11.25 CPU hours for msieve?

Sorry I'm so confused on this. . . Let me know how ignorant I am and maybe I'll go away, but probably not. I just won't run msieve on this machine, if I can't find a solution.

Thank you for any help. All comments welcome - even harsh ones. . .

[QUOTE=EdH;226326]Shouldn't msieve have reached 0.33 CPU hour long ago? It's been 12.5+ clock hours. Is that not 11.25 CPU hours for msieve?[/QUOTE]

What does [FONT="Courier New"]top[/FONT] say?

I'll give that number a go with the CPU version on my i5. (just the poly selection)

Edit: well, I would if I had the number (forgot that there were two c99s)

Is this a unix machine? It's possible that getrusage is not accurately computing the actual CPU time the program uses; IIRC there are some bizarre caveats about which unix flavor implements what part of the return data from getrusage...

This is my first implementation of Fedora 13 - possibly the issue. The 1.8GHz machine was running Fedora 11. I upgraded both machine and OS when that OS crashed.

[user@comp ~]$ uname -a
[code]
Linux comp.id 2.6.33.6-147.2.4.fc13.i686 #1 SMP Fri Jul 23 17:27:40 UTC 2010 i686 i686 i386 GNU/Linux
[/code][user@comp ~]$ top
[code]
top - 09:24:54 up 18 min, 3 users, load average: 0.74, 0.93, 0.72
Tasks: 143 total, 2 running, 141 sleeping, 0 stopped, 0 zombie
Cpu(s): 98.7%us, 1.3%sy, 0.0%ni, 0.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 508264k total, 416324k used, 91940k free, 21708k buffers
Swap: 1048568k total, 0k used, 1048568k free, 233672k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
2080 user 20 0 25456 7912 1156 R 98.0 1.6 0:54.02 msieve
1240 root 20 0 31124 12m 7592 S 0.7 2.5 0:13.94 Xorg
1623 user 20 0 146m 19m 9320 S 0.7 3.9 0:02.81 gmixer
2046 user 20 0 95640 12m 9380 S 0.3 2.4 0:00.62 gnome-terminal
2095 user 20 0 2696 1120 864 R 0.3 0.2 0:00.03 top
1 root 20 0 2828 1384 1172 S 0.0 0.3 0:01.42 init
2 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kthreadd
3 root RT 0 0 0 0 S 0.0 0.0 0:00.00 migration/0
4 root 20 0 0 0 0 S 0.0 0.0 0:00.00 ksoftirqd/0
5 root RT 0 0 0 0 S 0.0 0.0 0:00.00 watchdog/0
6 root 20 0 0 0 0 S 0.0 0.0 0:00.01 events/0
7 root 20 0 0 0 0 S 0.0 0.0 0:00.00 cpuset
8 root 20 0 0 0 0 S 0.0 0.0 0:00.00 khelper
9 root 20 0 0 0 0 S 0.0 0.0 0:00.00 netns
10 root 20 0 0 0 0 S 0.0 0.0 0:00.00 async/mgr
11 root 20 0 0 0 0 S 0.0 0.0 0:00.00 pm
12 root 20 0 0 0 0 S 0.0 0.0 0:00.00 sync_supers
[/code]The c99 is:
[code]
618155374139563156953657470966251220509792800441172795436567726667286308678511882481861288669912867
[/code]It is from iteration 2039 of aliquot sequence [URL="http://www.factordb.com/search.php?se=1&aq=55888&action=last20&fr=&to="]55888[/URL]. I'm going to interrupt my 24/7 machine here to see what it does. That one is running a c107 (via AliWin) under WinXP on the other sequence I have reserved.

As a side, but not distant, subject. If I were to set up a machine to primarily do factoring, what would be the better OS? I seem to remember something about Xubuntu being math (or is it scientifically?) oriented. The current machine supports a lot of things when I'm using it and will probably be Fedora based, unless Fedora has become too flawed.

Thanks for all. . .

Most people on the forum use Ubuntu I think.

[quote=henryzz;226376]Most people on the forum use Ubuntu I think.[/quote]Perhaps, though I don't use Ubuntu. I use RedHat (9 and EL5), Fedora, Snow Leopard, Win7, Vista, WinXP, FreeBSD and Suse. There may be one or two I've forgotten ...


Paul

[quote=EdH;226374]This is my first implementation of Fedora 13 - possibly the issue.

...

As a side, but not distant, subject. If I were to set up a machine to primarily do factoring, what would be the better OS? I seem to remember something about Xubuntu being math (or is it scientifically?) oriented. The current machine supports a lot of things when I'm using it and will probably be Fedora based, unless Fedora has become too flawed.
[/quote]What makes you think Fedora may be flawed?

In my experience, it doesn't matter what underlying operating system is used for a factoring machine. My experience goes back over 20 years and, probably, about 20 operating systems.

Paul

[QUOTE=EdH;226374]The c99 is:
[code]
618155374139563156953657470966251220509792800441172795436567726667286308678511882481861288669912867
[/code][/QUOTE]

OK, I'll try to coax some polys out of that.

[quote=xilman;226379]What makes you think Fedora may be flawed?. . .
Paul[/quote]
Just a thought of perhaps, actually. Fedora 11 ran Aliqueit, Msieve, etc. rather well. F13 has annoyed me already with several changes that were not for "my" benefit. Now I have to study even more about another OS version to make my computer work properly.:down:

I ran the c99 on my WinXP system and it started sieving after about .5 hour. I must admit, though, that SIQS is not looking very good on this machine either. The c91 only took a couple hours. This c99 is looking like >2 days. I do expect it to be factored by tonight on the WinXP machine.

My background with linux is very limited, even though I've been at it for several years. The reason I'm using Fedora is that it was the only one at the time that actually installed and found all my hardware on the laptop I was trying to use. It also worked on the desktop. SUSE and Ubuntu never ran. I did have Debian installed on the desktop for a while and that ran fine, but wouldn't work with the laptop.

Fedora appears to have almost all the programs I look for, represented within its repositories and they are all fairly current. This was not the case for some of the others I tried.