How can a system be completely stable when overclocking?

[Unkno]

Well, let's begin with my setup:

ASUS A8N-E Rev A3 Socket939 with Zalman ZM-47J (Passive NB cooler) 1013 BIOS
X2 3800+ Overclocked with AMD dual core driver and optimizer
X800GTO2
OCZ Platinum EL 2x1024mb
Antec Sonata II with Antec 450W PSU and front panaflo fan

My overclocked settings are: 256FSB with 10x multiplier and vCore=1.4V, Hyper Transport at 3x, Memclock at 333Mhz and ram latencies at 2.5-3-2-5 and vDIMM=2.6V

My problem is that whenever I used my overclocked settings, I get at least one BSOD every couple of days. I have tested with two instances of prime95 for 30hours on small FFT, 24hours on large FFT, 24hours on custom, and 12hours on blend. I have also tested my ram with memtest for 24hours (using the floppy, not windows).

According to speedfan, all of my temps are fairly safe. I am running a UPS with AVR and speedfan also reports that all of the voltages are pretty stable. What i find strange is that these BSODs don't even occur when the system is being stressed (like during a game or stress testing programs). So far, the blue screens have only occured during system idle/web browsing.

My system is completely stable when I'm at stock settings.

If you actually read up to here, I thank you!


Update on page 3, near the bottom of the page

 

[Jeff7181]

I'm going to state the obvious... your overclock isn't stable.

Either increase the voltage or decrease the frequency.

 

[starwars7]

You need to be able to run Prime 95 for at least 8 hours to consider your rig stable. Here is a nice guide, it's stickied at the top of this forum.:

http://forums.anandtech.com/messageview...atid=28&threadid=1497607&enterthread=y

You can follow the prime 95 instructions he has posted.

 

[Unkno]

Originally posted by: starwars7
You need to be able to run Prime 95 for at least 8 hours to consider your rig stable. Here is a nice guide, it's stickied at the top of this forum.:

http://forums.anandtech.com/messageview...atid=28&threadid=1497607&enterthread=y

You can follow the prime 95 instructions he has posted.

must have made the post too long......i've already ran two instances of prime95 for 30hours on small FFT, 24hours on large FFT, 24hours on custom, and 12hours on blend and 24hours of memtest86 on floppy......overkill...

 

[Stumps]

I haven't tried Memtest86 yet but my overclock(A64 3000+@2.67GHZ) can run prime95 for more than 52hrs with out any problems...come to think of it I've never had any real problems when OC'ing other than when sorting out the OC at the start(trying to find what works best).
once I found a good OC I found my machine run hard and stable for years(I've had my AXP 3000+@2.33Ghz and P4 3.06@3.45ghz since early 2003)

 

[LittleNemoNES]

Maybe it's just a driver issue. Try using it without the OC for a few days and see if anything changes. BTW, fresh install?

 

[Unkno]

yea, i've tried using it without overclocking for weeks now.....no problems whatsoever (knocks on wood)

it's somewhat fresh install.....the system is less than a year old....freshly installed windows maybe half a year ago at most

 

[starwars7]

strange, hopefully someone will have an idea for you, but I'm afraid I don't

 

[Jeff7181]

BSOD's are almost always hardware related... since your don't get them when your stuff isn't overclocked, it's a safe assumption that your overclock is making it unstable, regardless of what you think running Prime 95 for multiple days tells you. This really isn't the big mystery it's being made out to be...

Stock speed = no crashes
Overclocked = crashes

Solution = LOWER THE CLOCK SPEED

 

[Toro 45]

Originally posted by: Jeff7181
BSOD's are almost always hardware related... since your don't get them when your stuff isn't overclocked, it's a safe assumption that your overclock is making it unstable, regardless of what you think running Prime 95 for multiple days tells you. This really isn't the big mystery it's being made out to be...

Stock speed = no crashes
Overclocked = crashes

Solution = LOWER THE CLOCK SPEED

Agreed just back it off a bit

 

[MichaelD]

Originally posted by: Toro 45

Originally posted by: Jeff7181
BSOD's are almost always hardware related... since your don't get them when your stuff isn't overclocked, it's a safe assumption that your overclock is making it unstable, regardless of what you think running Prime 95 for multiple days tells you. This really isn't the big mystery it's being made out to be...

Stock speed = no crashes
Overclocked = crashes

Solution = LOWER THE CLOCK SPEED

Agreed just back it off a bit

I agree with this and the rest about Prime95, etc. Essentially, if you can use your rig on a daily basis for weeks on end with no crashes or BSODs, your rig is stable. If not, it's not.

 

[Conky]

The problem with any overclock is that it's only as good as it's weakest link.

It could be anything... your RAM, could be your motherboard, could be your power supply, or even your cpu. It can be software too. The only way to figure it out is to try various different combinations. Figuring out what is holding you back can be almost an exercise in voodoo science, hehe.

I couldn't get a stable overclock out of my ASUS board until I put the RAM into specific slots as the other channel caused memory errors. And before this motherboard I had 2 others that never did get stable(but they were admittedly very cheap) even when playing with the voltage.

And I can say that my overclocked system is perfectly stable but it took a while to get there.

 

[lopri]

The first thing comes up to my mind is the PSU.

 

[LittleNemoNES]

I think you need to increase the CL from 2.5 to 3 cos your ram isn't really meant for OCing (DDR400) so anything over isn't assured. 256 with 166(DDR333) divider is 213 mhz. Not much but some ram chips can barely take anything. Try running an even lower mem divider too.

 

[Unkno]

yea, i know it has something to do with the overclock....i've tried almost all of the variables i can think of...shouldn't testing with prime95 for like 30hours be enough for a stable system at idle that isn't even on 24/7?


it might be my psu but wouldn't the psu have unstable voltage lines?


One of the biggest problem that conflicts any possible explaination is why my system doesn't blue screen while being stress tested with prime95/memtest86 but it blue screens sometimes during idle...i kinda doubt it's software since there's no problem with the system if i just use stock settings (without changing any program settings or anything)


Can't seem to locate the weakest link....my thoughts are either the motherboard/chipset or the psu


Can my ram be the problem even if it is memtest86 stable? The stock latencies were 2-3-2-5 , so i set it to 2.5-3-2-5

Thanks for all the replies!

 

[LittleNemoNES]

sound strange. If it passed memtest then the only other thing I can think of is some unstable driver -- like from your vid card or sound.

 

[Jeff7181]

Originally posted by: Unkno
yea, i know it has something to do with the overclock....i've tried almost all of the variables i can think of...shouldn't testing with prime95 for like 30hours be enough for a stable system at idle that isn't even on 24/7?


it might be my psu but wouldn't the psu have unstable voltage lines?


One of the biggest problem that conflicts any possible explaination is why my system doesn't blue screen while being stress tested with prime95/memtest86 but it blue screens sometimes during idle...i kinda doubt it's software since there's no problem with the system if i just use stock settings (without changing any program settings or anything)


Can't seem to locate the weakest link....my thoughts are either the motherboard/chipset or the psu


Can my ram be the problem even if it is memtest86 stable? The stock latencies were 2-3-2-5 , so i set it to 2.5-3-2-5

Thanks for all the replies!

Absolutely. Prime95 and Memtest86 do not have the final say in what's stable and what's not no matter how long you run them. I don't care if you've run them both for 365 days straight, then open up Notepad and it crashes, it's NOT stable, period, end of story.

 

[nealh]

This is the issue with saying you have to run Prime 95 for some length of time and not crash to be stable...

He appears to be Prime95 stable but not functionally stable..who knows where the issue is...

Personally I like to be 10-15 hrs Prime 95 stable and mmetest stable at least 6hrs....but then I run winxp and see how I do video encoding and gaming

What i find strange is that these BSODs don't even occur when the system is being stressed (like during a game or stress testing programs). So far, the blue screens have only occured during system idle/web browsing

Asrock mobo has a known issue where if you run 1T on memory timings(I think it is only with DC) web browsing will crash even though the system is Prime95 stable..I experienced this..I forgot about the 1t and 2t issue ..I setup my wife's computer and forgot this well she was ticked

I know nothing about Asus mobos...but change the ram...1T vs 2T has little performance hit

 

[Conky]

The more I think about this the more I think it is probably the power supply.

Antec is a good brand(I have a 470 Antec) but I'd bet a dollar that something like this would make those random bluescreens go away.

 

[Unkno]

yea, i've read and thought about the 1T command rate....to eliminate this variable, i ran the same latencies (2.5-3-2-5 1T) on stock as overclocked but with the mem frequency at 200; there's no BSOD (knocks on wood)


if it's the powersupply, shouldn't it fail during the stress testing since that's when most of the power is drawn


what i'm thinking about trying is setting my cpu at 2560Mhz and with the same mem latencies (2.5-3-2-7 1T) but this time running a 133 mem divider making my ram freq at 169....this should isolate the problem if it's my ram

 

[nealh]

Originally posted by: Unkno
yea, i've read and thought about the 1T command rate....to eliminate this variable, i ran the same latencies (2.5-3-2-5 1T) on stock as overclocked but with the mem frequency at 200; there's no BSOD (knocks on wood)


if it's the powersupply, shouldn't it fail during the stress testing since that's when most of the power is drawn


what i'm thinking about trying is setting my cpu at 2560Mhz and with the same mem latencies (2.5-3-2-7 1T) but this time running a 133 mem divider making my ram freq at 169....this should isolate the problem if it's my ram

But overclocked I would still try a 2T...

 

[Conky]

Originally posted by: Unkno

if it's the powersupply, shouldn't it fail during the stress testing since that's when most of the power is drawn

Not necessarily. The power supply can have fluctuations that might not occur only at full power. I've noticed bluescreens like you mentioned on overclocked and overloaded(lots of HD's, etc) systems at times that were other than full load.

 

[maluckey]

Not necessarily. The power supply can have fluctuations that might not occur only at full power. I've noticed bluescreens like you mentioned on overclocked and overloaded(lots of HD's, etc) systems at times that were other than full load.

I agree. In the OC'ed setups that I have done over the last four or so years, I've seen PSU failures more than once. The load CHANGE seems to be the issue, not the amount of current. I had a particular PSU (I've killed many) go bad that worked fine at P95 and even a few games, but it would just die when asked to change loads quickly. I monitored it for three or so days and noted that under rapid load fluctuation, the +12v would dip as low as 11.35 volts for just a blink. Normally it would sit at 12.09 volts. BSOD normally happened at less than full load, sometimes when I EXITED an application.

 

[Parasitic]

I'd bump up the voltage on the memory and drop the timing slightly. Try 2.65v and CAS 2.5-3-3-7.

 

[Unkno]

hmmm....any ways to test if it's a powersupply problem (no i don't have a spare usable power supply and no i don't have a volt reader, lol)...need something software-wise...but then again this psu should be capable of powering this system


i'll try testing the ram with looser timings and higher voltage and the same frequency with my cpu overclocked later