Phenom II 955 X4-Voltage

stratego51

Distinguished
Nov 25, 2009
63
0
18,630
HI!,
I am trying to OC my 955 and so far I've got it at 3.7Ghz on 1.351v. I'm trying to get it to 4Ghz and cant get it passed ~3.75Ghz without it crashing or freezing. The first fail was at 3.8Ghz so I raised the voltage to 1.40v and still crashes. Am I safe to keep raising the voltage? or will it do something bad like fry it? XD

nf750-G55
8gb G.skill 1333
GTX 260
Ultra 650 PSU
 
Solution
I've gotten mine to 4.0ghz at 1.48v, 3.8 took 1.44~1.45. You can bump it up to 1.42-1.43 and try 3.8ghz. As the others have said, so long as your temps are fine it should be okay. A Quality (and beefy) PSU providing steady voltages is something that can help.

what are you trying to do exactly? Find the ceiling? not enough power? Keep in mind all chips will overclock differently and require different voltages. The phenom II chips generally chew through a lot of power at higher clocks. You can overclock to 3.6ghz without even bumping up the voltage at all, but as you go up from 3.6 you'll need to apply disproportionately more vcore to reach that >4.0ghz ceiling.

So don't go by what other people have done, especially when...

lowjack989

Distinguished
Oct 30, 2009
2,068
0
19,960
Max voltage is 1.55v but I implore you stay away from the max...I got my 965 at 4.1@1.425-1.44v...I have seen people going 4 GHz @1.52c...anything over 1.49v I will not do....All chips are not created equal remember that. WARNING: overvolting is dangerous for your chip please be cautious
 

stratego51

Distinguished
Nov 25, 2009
63
0
18,630

So if its not stable at 3.8 w/ 1.40v am I probably not gonna get any higher?
 

pelov

Distinguished
Jan 6, 2011
423
0
18,810
I've gotten mine to 4.0ghz at 1.48v, 3.8 took 1.44~1.45. You can bump it up to 1.42-1.43 and try 3.8ghz. As the others have said, so long as your temps are fine it should be okay. A Quality (and beefy) PSU providing steady voltages is something that can help.

what are you trying to do exactly? Find the ceiling? not enough power? Keep in mind all chips will overclock differently and require different voltages. The phenom II chips generally chew through a lot of power at higher clocks. You can overclock to 3.6ghz without even bumping up the voltage at all, but as you go up from 3.6 you'll need to apply disproportionately more vcore to reach that >4.0ghz ceiling.

So don't go by what other people have done, especially when overclocking. It is far more fool proof than it used to be, but ultimately it's always up to the user and the specific hardware to see how much they can get out of it. Bump up the vcore and multiplier slowly until you find your sweet spot, meanwhile always keep an eye on temperatures. 62C is the ceiling so you want to stay somewhere in the mid 50's.
 
Solution

lowjack989

Distinguished
Oct 30, 2009
2,068
0
19,960
@meagamanx-->lowering the NB would result in "slowing" the computer down...My NB is at 2800MHz@1.2v and it stays cool as a cucumber..and I have seen no impact on thermals from either a 2000MHz or 2800MHz NB.......I do suggest an aftermarket cooler...but I do not see your logic in saying that undervolting the NB will have any impact on CPU temps....????????????????
 

pelov

Distinguished
Jan 6, 2011
423
0
18,810


generally speaking it won't. the thinking is decreasing the voltage lowers the NB chipset temp and therefore the temp of the inside of the case, in reality it's extremely minimal and just not worth it. you can try undervolting it and seeing if you can achieve the same speeds and stability, but really that's just nitpicking.

On the other hand, i just noticed he's running a NF750 chipset and nvidia has always made chipsets that ran extremely hot. But it's still not worth undervolting.
 

stratego51

Distinguished
Nov 25, 2009
63
0
18,630
Ok its stable at 3.8 with 1.42v. . . .yay! now the NB voltage is set to auto and after reading on some other forums auto isn't the best for Overclocking so does the NB voltage need to be the same as the CPU voltage? or should I start from the lowest and keep raising it till I find the voltage that works?
 

stratego51

Distinguished
Nov 25, 2009
63
0
18,630


Thanks its stable now at 3.8Ghz with 1.42v. Yes was trying to find the ceiling and it is 3.7Ghz at default voltage. I'm confused about the CPU ratio though. Will the CPU be faster using a lower Multiplier and higher FSB? Will the system get more unstable with a really high FSB?? and then will I need to make a higher Multiplier and lower the FSB?

I hope my questions aren't confusing =D
 

pelov

Distinguished
Jan 6, 2011
423
0
18,810
They aren't, and it really depends on what you'll be doing with the PC. Generally speaking, in fact I can say comfortably that for nearly all people, you really don't need to touch the FSB at all on an unlocked CPU. If you want to try a mix of FSB/multiplier overclock it may help you achieve a higher clock rate, but then you're factoring in the RAM, the FSB, the NB, the ram voltage, the ram timings, and that's really unnecessary and complicated.

Yes, you can probably get it higher, but you'd have a lot of settings to fiddle with and a lot of testing to do. The point of buying an unlocked CPU is to avoid all of that and still achieve a good overclock :p

If i were you I'd leave the FSB and everything else alone. But if you really want to then get a boot disc with memtest86 and start to know your BIOS.
 

stratego51

Distinguished
Nov 25, 2009
63
0
18,630
Sorry about that guys I wont go that high "again" =D I got to 3.9Ghz at 1.50 ~ 1.53v and stable. . . I think. I still have to run prime. This was a stubborn CPU once you hit 3.8! I could not get it to 4Ghz at all! I tied it at 4Ghz with 1.63V and it crashed during 3DMark. I hope I didn't hurt it. It never got over 55c.
I really appreciate your guys help. I'm gonna go with 3.70ghz and bump it up to 3.90ghz when I get a better CPU cooler. I didn't want to buy one early if I couldn't OC it very much.

Thanks again for all the help! =D
 

edgaraslt

Distinguished
Feb 17, 2011
193
0
18,690
Anyone could help me setting my 955? I hav 955be with scythe katana3(def not too much paste), stock clocks 1.3500v. and at load it reaches 62c. My case is opened. so it's sure not an airflow problem.
 

Drock2017

Distinguished
Jun 17, 2011
19
0
18,510
I realise this is from a few months ago but i just got my 955 to 4.01ghz. Fsb is 200 Multiplier is x20 an my voltage is 1.412500 i ran prime95 for 4.5hrs with no issues. Should i run prime95 longer or is this considered stable??
 

edgaraslt

Distinguished
Feb 17, 2011
193
0
18,690
Check your temps. Also If you are going to play games you should run prime95&furmark at the same time. Because gpu heats a lot, and I saw some 5c difference on cpu temps with gpu at load and at idle.