View Full Version : Prime95: Do you care?
Drisler
10-31-2003, 02:48 PM
Copied from another forum:p I wanna know the feelings about this here.
So the question is...Do you care if your system is Prime95 stable?
mkleingeld
10-31-2003, 02:55 PM
primewhat?
There is more then superpi and pifast?
Drisler
10-31-2003, 02:58 PM
I don't use it either
When i see lines like "Oh my sys is 72hour prime stable..."...just makes me ughh.:rolleyes:
Holst
10-31-2003, 02:58 PM
not for 24hours I dont.
Ill run superPI 4meg a run of 3dmark 2001 if it dosent crash then ill just use my PC normally..
If it then crashes ill see if I can repeat the crash and drop my OC to compensate.
I usually run 5fsb less than max anyway, so testing prime for ages is pointless IMHO, especially as it often dosent pick up problems that general usage does.
Major
10-31-2003, 03:22 PM
You have problems if your system crashes prime95 right away (at least first 4 or 5 tourcher tests), as far as it running for days on end without errors, I don't care.
LaserEdge
10-31-2003, 04:13 PM
Having been a verification engineer in the past that worked on a several microprocessor designs I would say running Prime 95 for a couple of hours at most is all you need. The important thing for Prime 95 is to give it enough time for the CPU and other computer components to reach their max load operating temperature.
Memory testing like memtest86 is a more important test than Prime 95 IMHO. You definitely don't want to run a system if you are getting repeatable errors in a memory tester.
The ultimate test would be some software code to specifically test all the cricital timing paths in the system. Of course AMD, NVidia, ATI etc is not going to let us know where their critical timing paths lie. That is trade secret information. If I worked on the design of the Athlon 64 myself I would write such a specific piece of code to verify stability of the Athlon 64.
Even still the fabrication process has a large degree of random factors. A timing path that might not normally be the critical timing path could become critical for a specific chip. So I would say use a memory tester first, run 3dmark, run prime 95 for a couple of hours and do a little super PI. From that point it is best to use the system if you haven't see any problems. If you find any failures see if you can repeat them. If they are repeatable see if they go away with a lower overclock.
i fail memtestx86 on the second test at the same point every single time with either, or both of my 3500 corsair, regardless of overclock or voltage or timings.
So if theres something i dont trust its memtest, cos prime passes, 3dmark passes, and nothing ever crashes.
of course i used to be able to run 2226 with this mem, then suddenly it became unstable and i could only run 2236 so something dodgy went on somewhere. but it IS stable at 2236.
KnightElite
10-31-2003, 04:45 PM
I'll run it to check the immediate stability of an overclock (eg. does it crash within 5 minutes of starting), but I rarely do more than that. If it crashes during normal usage, I will back off the OC (IRQL_NOT_LESS_OR_EQUAL anyone?).
speedstream5621
10-31-2003, 04:58 PM
I lost faith in Prime95 when it errored after three hours and then errored about give minutes into playing Raven Shield.
It only stopped when I lowered the o/c and upped the vcore.
LaserEdge
10-31-2003, 05:22 PM
Running a system that fails memtest in the exact same spot over and over is like playing Russian Roulette. You might be okay for now, but sooner or later that fault in the system is likely to get you. Its your choice to keep playing the odds. If it is very isloated case you may never hit it. Then again the right application could come along and hit that case all the time. It could be that you do hit they error frequently. It only effects some non-critical data in the aplication... sound, graphics etc.
Prime95 is the only program that works awesome for me, but i will only do for like a few hours, if it passes its all good. It must work cuz it doesnt crash on anythign :banana:
Stang_Man
10-31-2003, 08:52 PM
i dont use prime for stability testing
TheWeaseL
10-31-2003, 11:43 PM
I use it, in a combo. of things. Prime, memtest, play a couple games. Some SuperPI, of these things. Passes them, stable enough for what I do.
L0$t Pr0PhEt
11-01-2003, 12:02 AM
I let it run for 1-2h and then do a some benches.
BigDov
11-01-2003, 02:00 AM
I don't use it at all. I figure if I can sit in the basement and frag away in UT2K3 @ 1280x1024, 32bit, with all settings to high or highest for 6 to 8 hours at a whack, I'm golden.
Spec3
11-01-2003, 03:19 AM
I used to use it all the time but now it just gives me problems. I can pass any other benchmark BUT prime so I said screw it
KingInge2000
11-01-2003, 03:51 AM
I need Prime running for 30min-1h to feel "save".
Originally posted by LaserEdge
Running a system that fails memtest in the exact same spot over and over is like playing Russian Roulette.
no it isnt because there IS nothing wrong withthe memory or the system. I took the memory out and stuck it in another pc. ran the same copy of memtest on it and it passed just fine.
so memtest is about as reliable as londons public transport.
prime on the other hand over the course of the last 5 years has picked up EVERY single error ive ever had due to overclocking, and every single time that its been prime stable- so has everything else. every single time prime has failed, something else has also crashed at some point. I have had occasions where i didnt test prime thoroughly enough and it seemed to pass, then some time after something crashes, went back and tested prime a bit more thoroughly and sure enuff it was failing one one of the latter tests that i didnt get to.
the small prime tests are pretty much useless as ive never had a single failure of any kind on those, stick to 400k+.
There are ocasions where only a specific test will show instability, like maybe the 768k test, where it would pass over and over and over on the tests before it, so it does need testing properly, and it ISNT just about temperature.
and anyone that is running seti, folding or any of those without being 100% prime stable, is wating their own time, and the time of the project and isnt helping in the slightest because youll be sending back corrupt, invalid results which then have to be sent out again to another user whos system IS stable.
anyway this topic has been done to the death dozens of times, you people believe what you want.
Iridium192_217
11-01-2003, 09:43 AM
I dont, I have found prime95 to be rather unreliable
I use games & seti to test stabilty
Sarcastro
11-01-2003, 10:10 AM
I don't take anything less than a 24h prime95/F@H combo.
jagare
11-01-2003, 12:32 PM
I run 2 Prime95's to test stability usually.
LaserEdge
11-01-2003, 01:29 PM
Originally posted by Ewok
so memtest is about as reliable as londons public transport.
I think you missed my point. Running memtest is just one indicator of system stability. In the situation you mentioned it sounds like the CPU itself was unstable. Running prime 95 is just one of many ways to test CPU instability. It just so happens that prime95 seems to have a rather good coverage of the all the CPU path ways. Hard to say exactly what the precentage of the path coverage is with prime 95. Its not like I can run surecov on a simulation of the CPU to find out. :p:
My own approach is to not even boot into windows until I know memory test is passing. I also check the PCI bus frequency before booting into windows. I don't like corrupting the OS because the PCI bus is running to fast. By doing all this I have won a large chunk of the overclocking battle. I atleast know my memory subsystem and disc I/O is stable. Then you have to start testing other sub systems like CPU and graphics.
This is just my own preference in testing for stability. Part of what makes overclocking fun is just that there are some many ways to achieve the same goal. Its all good. :)
JoeBar
11-02-2003, 05:22 AM
I allways use prime95 (2 instances) for stability testing.
What does prime95 is to test whether your cpu is calculating right. If it fails prime your cpu isn't calculating right. However the things that u do on your pc propably aren't such cpu intensed, so u may think that u have a stable system cause u run 3dmark2001 or u played an hour of gaming without probs. But if u do jobs like folding, rendering, video encoding u will soon find out that your system isn't that stable. ;)
My opinion is test your system for whatever job u need it. If u want to surf the internet, play some games and use ms office, there's no need to pass prime for 3 hours... :p:
I use SuperPi to make sure my memory isn't causing errors... then I use Prime95 to make sure I have enough juice going to the CPU for my selected speed... then I like to prove that PiFast can run a few time(if not, a slight bump of Vcore usually helps), then I finish off with 3DMark01/03 to make sure everything stays stable during a mixed test.
MudWhistle
11-02-2003, 11:04 AM
My 2 cents:
Prime 95 as a systems stability check application has yet to be surpassed by any other program. 100% prime stable over 24hrs is a true test for stability in the areas it focuses on. Nortbridge/CPU/Mem is what prime focuses on and does it well.
It's rare but I have seen 100% prime tested machines still crash, but the crashing is never related to what prime95 focuses on when testing. The crashes are usually related to AGP/Videocard and Southbridge related devices like sound cards or IDE controller problems.
There is no 100% failsafe way of benchmarking a computer, although you can come close.
I prefer running memtest86 first, but be aware of memtests limitations. Memtest will pick up any errors that are caused by the memory controller, and not just the memory itself. It's up to your judgement to be able to determine what device is actually at fault. For example, if you take memtest86 and run it on the older but quite common chipset (intel i815) you will most definatley get metest errors in the same locations regardless of what memory you use.
Some of the hardest stability problems to solve are the problems that stem from one device but affect another. It's always good to determine your northbridge/mem controller/cpu are as close to stable as possible before trying to troubleshoot stablity problems.
st0nedpenguin
11-04-2003, 10:45 AM
24 hours of Prime95
24 hours of MemTest86
24 hours of 3DMark2001
24 hours of 3DMark2003
Takes a while, around four days surprisingly :D, but it makes sure the system is rock solid stable, there aren't many things more annoying than a 4 hour video encoding session crashing at 92%.
Plus, Prime95 is a handy barometer for stability, I just clock until it won't benchmark any more, drop down a nothch, and fire up the stability test, if it's really unstable it'll bomb after about 5 minutes, saves a lot of time.
lalPOOO
11-04-2003, 11:43 AM
I've found that while prime95 isn't 100% required, if my system won't pass that, it usually won't work for rendering either. It may still work for games, and thats all some people need, but if the cpu isn't 'working' the cpu isn't working, so eventually they'll probably run into the problem.
As for memtest, I generally run it anytime I change the memory settings; its a pita to have to reinstall windows when you don't really have time.
At least 2 passes of memtest86 and an hour of Prime95 before i consider my system stable.
If it can run 3D mark i'd say it's 100% stable.
TechTones
11-04-2003, 04:03 PM
I can say the person who asked this question in the first place can't get Prime running OK so he's seeking to feel better by asking others how unimportant is it when he really knows it's important and would like it to run. Been there done that :D
Smokin_Joe
11-04-2003, 05:51 PM
I don't use it. I'll run f&h and surf the web for a few hours or run 3dmark loops with max details and try a few games.
Drisler
11-04-2003, 05:54 PM
Originally posted by TechTones
I can say the person who asked this question in the first place can't get Prime running OK so he's seeking to feel better by asking others how unimportant is it when he really knows it's important and would like it to run. Been there done that :D
YOU are incorrect.
One should not make assumptions.;)
TechTones
11-04-2003, 06:05 PM
Originally posted by Drisler
YOU are incorrect.
One should not make assumptions.;)
Then why do you ask about it?
sjohnson
11-04-2003, 06:08 PM
Prime95 is one of the tools I use. I look at it this way - if even one of the test tools I use fails where the others are succeeding it gives me a clue regarding something that's not quite right.
Drisler
11-04-2003, 06:17 PM
Originally posted by TechTones
Then why do you ask about it?
Did you, by chance, read the first post of this thread?
I remember stating my reason :)
Running Prime95 for hours is plain stupid :D.
Never had crashing problems with systems that can handle ~10 minutes of prime95... and i do run F@H 100% 24/7. But the thing is that F@H never stresses the CPU/MEM as much as Prime95 does so 24h prime is a OVERKILL.
But hey, if you wanna REALLY play it safe, go for it. :toast:
PTK
Originally posted by st0nedpenguin
24 hours of Prime95
24 hours of MemTest86
24 hours of 3DMark2001
24 hours of 3DMark2003
Takes a while, around four days surprisingly :D, but it makes sure the system is rock solid stable, there aren't many things more annoying than a 4 hour video encoding session crashing at 92%.
:rocker:
Heh, i would call 4 days of stability testing more annoying than 4 hours encoding crash ;).
PTK
vector7
11-05-2003, 03:31 AM
Just a another tool to find out what is holding your system back. It also depends how mission critical your apps are to really need to be 100% stable all the time. If you have a spare server to do the important stuff just just kick that Millenium Falcon when it blue screens...:)
Hardass
11-05-2003, 04:15 AM
Originally posted by TechTones
Then why do you ask about it?
Members here have the right to ask any question within our forum rules they wish, without having other members such as yourself come into their thread and attempt to start trouble. You are on thin ice with me on this. If you want to make a statement on the question asked do so without attemting to start trouble.
Hardass.
Edward2
11-05-2003, 05:27 AM
I usually run Prime for about 30 minutes to 1 hour, along with several other benchmark/stress testing programs. The real test for me is the Folding client, and it runs 24/7.
I have seen it go both ways. I have had computers pass Prime for 12+ hours and crash while Folding within 15 minutes. I have also had computers fail Prime and run flawlessly for months while Folding.
st0nedpenguin
11-05-2003, 06:02 AM
Originally posted by PTK
:rocker:
Heh, i would call 4 days of stability testing more annoying than 4 hours encoding crash ;).
PTK
What can I say, I'm a perfectionist who doesn't believe in perfection, my whole life is a paradox. :D
I just want to make sure everything is nice and stable, and as I'm at work for most of the day and busy half the night, I may as well leave my PC doing something, call it a burn-in, and while running Prime95, at least I can use my PC if I need to, although 3DMark is another matter. :D
I did try running 3DMark and Prime95 at the same time, to cut down on the long slog, but Prime95 tends to get left with crumbs of CPU time, and it doesn't make a fair test really, it only gets a few hours of testing done in that 24 hours.
RichBa5tard
11-05-2003, 06:08 AM
Prime95 stability matters to me. :)
I've got 2 pretty identical rigs. A 2.6c @ 3.25Ghz and a 2.8c @ 3.6Ghz on both a IS7. One for work (software development) and one for play.
Obviously, the one for software development has to be 100% stable. If it doesn't pass prime for 24h, I can't fully trust it.
My other rig is solely for gaming and movies. It's a 2.8C at 3.6Ghz with stock cooling /vcore, but after a few hours of prime it usually fails. A few hours is still good enough to play games, I haven't had any problems yet.
JoeBar
11-05-2003, 06:08 AM
One notice.
I'm amazed that till now nearly 50% believes that prime95 is pos... :eek:
There must be many gamers here... :)
RichBa5tard
11-05-2003, 06:11 AM
Originally posted by JoeBar
One notice.
I'm amazed that till now nearly 50% believes that prime95 is pos... :eek:
Nah, I think 90% believe Prime95 is good for testing a mission critical rig.
Whether everybody uses their rig for serious work or not, is another question. ;)
-edit-
"There must be many gamers here... "
Do you think you need a prommy on your 3.2C to compile Java or use OpenOffice fluently? Heck no, we want 500fps in UT2K3 :P
st0nedpenguin
11-05-2003, 06:16 AM
I primarily use my machine for gaming and other leisure pursuits, but there's nothing more annoying than having it reboot during a BF1942 0wnage session. :D
TechTones
11-05-2003, 06:22 AM
Yes to me Prime95 is very important. In fact, it's rumored that Intel uses it to test their own processors. Prime95 runs numerous
calculations and stresses the CPU to it's max.
If Prime doesn't run, the CPU and ram is not in a stable state.
It's Unstable.
Would you want a car that runs OK but stops running all of sudden on a hot day far from home? You'll never know when it will crap out. It's the same analogy.
Now even if you can run other apps and games OK, it would bother me mentally all the time that my system wasn't perfect. I think it's also more of a personal "pride" type of thing.
Everyone wants their system to be "perfect". To be the Best it can be. I would rather run a slower system and take it down a notch but be able to run Prime all day. Then I know my system is
solid and dependable.
Yes it's also true that you can run Prime fine and have it fail at other things like 3d but I'd rather have to deal with that then deal with Prime not running. If Prime runs and 3d fails, you can usually fix it pretty easily.
TechTones
11-05-2003, 06:23 AM
Originally posted by st0nedpenguin
What can I say, I'm a perfectionist who doesn't believe in perfection, my whole life is a paradox. :D
:D :D :D
My man the Penguin!
JoeBar
11-05-2003, 06:24 AM
Originally posted by RichBa5tard
Nah, I think 90% believe Prime95 is good for testing a mission critical rig.
Whether everybody uses their rig for serious work or not, is another question. ;)
I agree totally.
"There must be many gamers here... "
Do you think you need a prommy on your 3.2C to compile Java or use OpenOffice fluently? Heck no, we want 500fps in UT2K3 :P
:lol: