Squeezing more out of Phenom II

[OVerLoRDI]

So I'm running a Phenom II X4 940BE, it is currently overclocked to 3.5ghz @ 1.425v. I got an impressive performance increase from 3 to 3.5ghz. I want to squeeze a bit more performance out of it. I want to hold out to see what Bulldozer offers before I upgrade. My main use is gaming.

So I have a few questions.

Voltage, what is too much? I care about my chip living a decently long and stable life.

Ram Speed, Currently running at DDR2-800. My modules are good for up to 1066, but the Phenom II controller can't do 4 modules at 1066. Will I see any benefit from pushing my ram speed up as high as possible?

HT Link, Will I see any benefit by increasing this? Currently it is at 1.8ghz.

My temps are also quite good, I have the 120mm xigmatek cooler, I hit 52C on Prime95 Large FFTs (the max heat test)

Thanks guys

 

[Castiel]

I ran my 4.2Ghz 955 C3 at 1.58v for 6 months without any issues whatsoever. That's a C2 correct? So it's probably not going to go very much higher.

 

[SickBeast]

Keep the HT link at 1.8ghz.

I run my Phenom II at 1.5v on the CPU, and 1.5v on the CPU-NB. I overclock my CPU-NB to 2400mhz.

This is the best guide I have found regarding overclocking the Phenom II:

http://www.techreaction.net/2010/10/14/phenom-ii-imc-ram-overclocking-guide/

As for your memory, it depends on the type of tasks you run. For gaming, tighter timings at lower speeds is faster. For photoshop and video encoding, you're better off with looser timings and higher frequencies.

You might need to give a little bit of extra voltage to your HT Link and your memory. Just be careful not to give them too much. A 0.1v increase is probably enough. I wouldn't exceed 0.2v over stock, personally.

Good luck! :thumbsup::thumbsup:

BTW you're doing this at your own risk! I'm not responsible for what you do with your own hardware! D:

 

[busydude]

Next logical step is to overclock the northbridge.

 

[OVerLoRDI]

Keep the HT link at 1.8ghz.

I run my Phenom II at 1.5v on the CPU, and 1.5v on the CPU-NB. I overclock my CPU-NB to 2400mhz.

This is the best guide I have found regarding overclocking the Phenom II:

http://www.techreaction.net/2010/10/14/phenom-ii-imc-ram-overclocking-guide/

As for your memory, it depends on the type of tasks you run. For gaming, tighter timings at lower speeds is faster. For photoshop and video encoding, you're better off with looser timings and higher frequencies.

You might need to give a little bit of extra voltage to your HT Link and your memory. Just be careful not to give them too much. A 0.1v increase is probably enough. I wouldn't exceed 0.2v over stock, personally.

Good luck! :thumbsup::thumbsup:

BTW you're doing this at your own risk! I'm not responsible for what you do with your own hardware! D:

Thanks for the useful guide

 

[SickBeast]

Thanks for the useful guide

You're welcome.

FWIW my Phenom II 905e overclocks to 3.75ghz on 1.55v, with the northbridge at 2400mhz. It's more voltage than I would like, but for what I paid for the CPU I can't complain really.

 

[BD231]

AMD stated their SOI process is good up to 1.55v. I bought a phenom II x3 about a year and a half ago I believe. Its been running @ 3.72ghz/1.54v ever since, with a north bridge of 1.334v/240mhz.

You don't need much extra voltage on the North Bridge as the general wall on C2 chips is 240/250. 1.3/1.4 range should be enough for that.

 

[superccs]

Yeah to get better system performance you have to bump the FSB to closer to 230Mhz or something and throttle your ram up to ~1000Mhz or whatever you can get to work.

 

[Jovec]

I doubt anybody has enough experience to state anything definitive. Most would consider 1.5v max (for longevity), with the possibility of 1.55v/1.6v if you have the cooling and watch your temps. C2s probably won't hit 3.9/4.0+ with a 64-bit OS. Of course every chip varies, but running the CPU-NB at 1.5v seems high, especially for only 2.4. I could hit 2.84 (240x12) CPU-NB on my 940BE at 1.30 (maybe 1.35v), with the CPU at 240x16@1.45v. Higher CPU-NB voltage will increase your temps noticeably. Upping your RAM speed won't have much real-world benefit - it's definitely worth dropping RAM speed/divider if needed to increase CPU and CPU-NB.

I'm not convinced about the HT link staying at stock 1.8 or 2.0. When I ran tests of DoW2 (the most demanding game I own with a built-in benchmark) I saw consistent minimum FPS improvements at max detail levels by running at 2.6 on the HT link. I might try more tests with ArmA2's benchmark tool now that I own that game.

 

[SickBeast]

Yeah I don't know why my CPU-NB needs 1.5v to run at 2400mhz but it does. My system can boot into Windows with it at 2700mhz, but it's not stable at all. My CPU is a C3 which makes it that much more odd.

As for the HT, I agree with you Jovec, but IMO you should leave it at 1800mhz until you've finalized your overclock. Anything you can get out of the HT is gravy at that point, although some people say it makes no difference or even has a negative impact.

I had an epic fail of an overclock where I had to completely reinstall Windows; I couldn't even repair it. I had the HT at 2400mhz and I have a feeling that it was the culprit.

 

[BD231]

Yeah I don't know why my CPU-NB needs 1.5v to run at 2400mhz but it does. My system can boot into Windows with it at 2700mhz, but it's not stable at all. My CPU is a C3 which makes it that much more odd.

As for the HT, I agree with you Jovec, but IMO you should leave it at 1800mhz until you've finalized your overclock. Anything you can get out of the HT is gravy at that point, although some people say it makes no difference or even has a negative impact.

I had an epic fail of an overclock where I had to completely reinstall Windows; I couldn't even repair it. I had the HT at 2400mhz and I have a feeling that it was the culprit.

Are you using DDR2 with that 905e?

 

[SickBeast]

Are you using DDR2 with that 905e?

No, it's 1333mhz DDR3.

 

[Spikesoldier]

in all fairness, the 940 was one of the first phenom II's, so in addition to being 125w for a quad, i can gather its an early C2 stepping. 3.5 may be the most you can get out of it. but, i would not hesitate to throw 1.5v vcore at it, if you have the cooling.

if you cant get any more, i would try to get max uncore clock as others have said.

 

[Rhoxed]

I run my 940BE @ 3.9ghz - 1.52V / 2.8ghz NB - 1.4V - 8GB DDR2-1066 @ 1066 24/7. I bought it Feb 1st 2009.

for what its worth, i had another 940BE that i sold to my brother that maxed out at 3.75ghz no matter the volts - so YMMV

 

[veri745]

I doubt anybody has enough experience to state anything definitive. Most would consider 1.5v max (for longevity), with the possibility of 1.55v/1.6v if you have the cooling and watch your temps. C2s probably won't hit 3.9/4.0+ with a 64-bit OS. Of course every chip varies, but running the CPU-NB at 1.5v seems high, especially for only 2.4. I could hit 2.84 (240x12) CPU-NB on my 940BE at 1.30 (maybe 1.35v), with the CPU at 240x16@1.45v. Higher CPU-NB voltage will increase your temps noticeably. Upping your RAM speed won't have much real-world benefit - it's definitely worth dropping RAM speed/divider if needed to increase CPU and CPU-NB.

I'm not convinced about the HT link staying at stock 1.8 or 2.0. When I ran tests of DoW2 (the most demanding game I own with a built-in benchmark) I saw consistent minimum FPS improvements at max detail levels by running at 2.6 on the HT link. I might try more tests with ArmA2's benchmark tool now that I own that game.

Chips start to degrade (quickly) once you're north of 1.55V. I personally wouldn't go over 1.5

 

[BD231]

No, it's 1333mhz DDR3.

Honestly I'm surprised your north bridge even works properly at that voltage .... :hmm:

Most overclocking reviews stated the NB was sensitive to high voltage and I thought I proved this to myself by trying to push my X3 past 1.356v on the north bridge. Like you I screwed up my Win7 OS install. That only happened once but I was running the core at 3.9+ ghz as well so that was also a factor.

Amd chips really do vary it would seem. A buddy got an OEM x3 740 that dose 3.6ghz @ 1.380v. Mine wont even boot at those settings.

 

[richierich1212]

What motherboard are you using? Your NB voltage is way too high. NB Voltage only needs to be around 1.25v - 1.3v for only 2400MHz. Maybe bump up CPU-NBvoltage to 1.25v - 1.3v and see if that helps. Also you might need so much voltage because all four-dimm slots are occupied.

Try seeing if it helps improve overclocking with less voltage by taking out a couple of sticks. If so, maybe try seeing how much performance is lost with only two sticks.

 

[SickBeast]

What motherboard are you using? Your NB voltage is way too high. NB Voltage only needs to be around 1.25v - 1.3v for only 2400MHz. Maybe bump up CPU-NBvoltage to 1.25v - 1.3v and see if that helps. Also you might need so much voltage because all four-dimm slots are occupied.

Try seeing if it helps improve overclocking with less voltage by taking out a couple of sticks. If so, maybe try seeing how much performance is lost with only two sticks.

MSI 770-G45

The motherboard NB is somewhere around 1.2v. The CPU-NB is at 1.5v, which is the same as the vcore at 1.5v as well.

I needed this much vcore even with only 2 sticks of ram.

Thanks for your input; I'm going to experiment some more to see if I can get my voltages down somewhat.

 

[poohbear]

another great guide on overclocking phenomIIs from an AMD insider can be found here:

http://www.bit-tech.net/hardware/cpus/2009/05/11/overclocking-amd-s-phenom-ii-x3-720-be/1

sickbeast's techreaction link is indeed the best one.

 

[busydude]

sickbeast's techreaction link is indeed the best one.

Haha.. I just noticed.. the author of that article is Slappa!.. :awe: