Max safe voltage for PII 955?

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TeeJay

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Elloh.

I'm trying to get this beast to hit 4.0GHz. I got a stable 3.8GHz @ 1.55V @ a maximum of 43c @ full load. So now I have to start doing this from the BIOS since the max voltage I can go for is 1.55V from AOD...But the thing is I don't know what's the max safe voltage...

Thanks
 
1.55 is about as high as you would want to go for 24/7 use. As long as the chips stays below 65c you should be ok.
 
mess around with the multi and other settings, you shouldnt need 1.55 to get it to 3.8......ive had my Castillo(the 2 core version...nearly same, yes i know some differences), at 3.7 with only 1.375 v(which was set by the bios automatically)...maybe a bit of tweaking will get ya where you want to go ?
 
I read that it can also depend on whether your running a 32 bit or 64 bit system. A 32 bit system doesn't use all the registers so it can be pushed harder, a 64 bit system is a bit harder on the cpu and won't clock quite as fast.
I'm running my PHII 955 at 18.5 x 206 =3.8 and I needed 1.5375 volts to do it. Any less than that and whenever the system is pushed it locks up instantly. I too wanted to try to hit 4.0, but I don't want to kill my cpu by running out of spec, I'm very happy at 3.8.
And at this multi cool and quiet still works too.
 
Dude, there is no Pentium II going to 4GHz

what's that?...oh...

never mind
 
I require 1.55v for 4GHZ but only 1.48 for 3.9Ghz so of course I stay at 3.9 for 24/7 computing.
 
W.Feather said:
mess around with the multi and other settings, you shouldnt need 1.55 to get it to 3.8......ive had my Castillo(the 2 core version...nearly same, yes i know some differences), at 3.7 with only 1.375 v(which was set by the bios automatically)...maybe a bit of tweaking will get ya where you want to go ?
Click to expand...

Dual core requires less volts than quads.... :rolleyes:
 
Exeodus said:
1.55 is about as high as you would want to go for 24/7 use. As long as the chips stays below 65c you should be ok.
Click to expand...

63C is the max for the Ph-II AFAIK. Mine started losing Prime95 threads at 64-65C at default speeds when I used a crappy cooler. This is different from the Core2 and i7, which have max temperatures of about 68 - 72C.

Also, higher voltages reduce the max stable temperature even more, so you'll want to stay below 60C I think. Nominal voltage as specified by AMD is 0.875V to 1.5V.
 
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Heat is not much of a problem. I did 3.8GHz @ full load for like 2 hours and the max temp was somewhere around 43-45c.

As for hitting a high clock\voltage "for 24\7 use"...I use AOD and theres a green button on the top right corner I guess everyone knows about...I clock down the CPU to 800MHz at all times, I only clock it up to 3.8 when I'm gaming...So it's not really a problem >.<

About a stable 3.8GHz, I did 1.5375V...And when I ran the stability test in AOD, I did it for 20 minutes and it was stable...Yesterday when I was leaving home I thought I'd leave a test on for 2 hours until I come back, and it actually crashed. When I returned home and found out about this, I did 1.55V and re-ran it for 2 hours and left, and it was stable...We all don't get the same chips...You know? :p

Thanks though guys!
 
JimmiG said:
63C is the max for the Ph-II AFAIK. Mine started losing Prime95 threads at 64-65C at default speeds when I used a crappy cooler. This is different from the Core2 and i7, which have max temperatures of about 68 - 72C.

Also, higher voltages reduce the max stable temperature even more, so you'll want to stay below 60C I think. Nominal voltage as specified by AMD is 0.875V to 1.5V.
Click to expand...

62C is the rated max temp but mine doesnt start losing threads til 69C.. and then shuts off at 72C

core 2 has a Tjmax of 85(65nm) and 90C(45nm) if i remember correctly and the i7 has a TJmax of 90C i believe.. the system AMD uses vs intel is not the same.. AMD uses a true max temp while intel uses a rated max temp for stock clocks with a stock cooler but actually means nothing.. also their temps are purely based off the TJmax of the processor type.. eg. 65nm, 45nm use different tjmax's.. core 2 and i7 use different tjmax's but no one really knows what they are anyways.. they are just an educated guess by the groups making the monitoring software since intel wont release the information..
 
TeeJay said:
As for hitting a high clock\voltage "for 24\7 use"...I use AOD and theres a green button on the top right corner I guess everyone knows about...I clock down the CPU to 800MHz at all times, I only clock it up to 3.8 when I'm gaming...So it's not really a problem >.<

About a stable 3.8GHz, I did 1.5375V...And when I ran the stability test in AOD, I did it for 20 minutes and it was stable...Yesterday when I was leaving home I thought I'd leave a test on for 2 hours until I come back, and it actually crashed. When I returned home and found out about this, I did 1.55V and re-ran it for 2 hours and left, and it was stable...We all don't get the same chips...You know? :p

Thanks though guys!
Click to expand...
Most OCers I think, use BIOS to OC, AOD is nice to get a ball park figure or if you do not care for getting every last ounce of performance or for suicide screens since you bypass the sometimes hard process of booting.
I normally just run OCCT 1 hour and that is enough for anything I do. When I want to test RAM then I run prime for 2 hours on Blend just in case.
So far the 1 hour OCCT is my best shorcut tool. :)
You got good temps so no worries there.
 
I need 1.5v+ to do 3.8ghz on my 955BE

Yet I can do 3.6ghz@stock.

Not all 955s do 3.8@low vcore. and as said more cores + 64bit vs 32bit have big effects on speed and voltage reqs.


To truly be stable you need to be able to pass a torture test for 10+ hrs, some will say 24, especially if you do any kind of distributed computing.

Many times I have seen an oc do 10 hours of prime stable but fail at 12h, or even pass 20h then generate errors coming up on 24.

If you do not do distributed computing, where your cpu is under load 24/7 and the results of your computations will matter, then 10h is fine, IMO
 
TeeJay said:
Heat is not much of a problem. I did 3.8GHz @ full load for like 2 hours and the max temp was somewhere around 43-45c.

As for hitting a high clock\voltage "for 24\7 use"...I use AOD and theres a green button on the top right corner I guess everyone knows about...I clock down the CPU to 800MHz at all times, I only clock it up to 3.8 when I'm gaming...So it's not really a problem >.<

About a stable 3.8GHz, I did 1.5375V...And when I ran the stability test in AOD, I did it for 20 minutes and it was stable...Yesterday when I was leaving home I thought I'd leave a test on for 2 hours until I come back, and it actually crashed. When I returned home and found out about this, I did 1.55V and re-ran it for 2 hours and left, and it was stable...We all don't get the same chips...You know? :p
Click to expand...

TeeJay, any advice or links for optimal AOD usage? I find the default AMD user info lacking to say the least and haven't found a good user tutorial. Considering this was a highly touted AMD feature, I have found it sucks and all detailed info on using it to suck as well. Can you help or provide some advice as it seems to rock for you.
Thanx
 
funkydmunky said:
TeeJay, any advice or links for optimal AOD usage? I find the default AMD user info lacking to say the least and haven't found a good user tutorial. Considering this was a highly touted AMD feature, I have found it sucks and all detailed info on using it to suck as well. Can you help or provide some advice as it seems to rock for you.
Thanx
Click to expand...

You probably have it selected as "Novice Mode"...Go to prefence, under "Control Performance Mode" click "Advanced Mode"...Now go back to Performance Control, click the Clock\Voltage tab...And there you get everything...It's pretty simple really...You just have to raise your multiplier and voltage...Here, take a look:



Thing is that this software will only give you access to 1.55V @ CPU...That means if you want to go 1.55V+ you'll have to do that from the BIOS(Which I had to do to get a stable 4.0GHz), I was only able to get a stable 3.8GHz from AOD @ 1.55V.

As you can see after switching to Advanced Mode, you can also control your Memory(I don't realy know how, never did it before)...

The software also has a built-in Benchmarks...As well as a Stability test to ensure yourself a stable clock. It's even very detailed on the Stability Test. Just make sure you click the Status Monitor while doing it so you stay safe.

Hope this helped...If you need anything else, PM me

EDIT: If you noticed my ACC is @ Auto. It's because it helps get a better stable clock, which is what I have been told from many people.

So just raise your multiplier a bit then your voltage a bit until your PC crashes or AOD clocks your CPU back to stock(that means it found an error and that clock is not stable so it clocks your CPU back to stable)...If it crashes then re-open AOD and clock back to the last best result you got.
 
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Does changing ACC to a manual setting help at all? I've played around with it a little bit and haven't noticed anything.
 
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