Post your CPU-NB frequency + voltage

[cdawall]

athlon II X2 250 regor 0920 3500mhz 1.375v (DICE) pic
Phenom II X4 945ES BE 0825 2940mhz 1.45v (water)
phenom II X4 955BE 0908 3150mhz 1.375v (DICE) pic
phenom II X2 550BE 0921 3375mhz 1.4v (DICE) pic
phenom II X4 910 2600mhz 1.25v (air)

[Rippthrough]

But looking at the specs from the document above, the CPU-NB can withstand significantly higher voltages anyway? (Since it's part of the CPU, I would assume it could take the same as the chip does?)

[Kei]

My Northbridge is fantastic on my chip. On the temporary board I'm using right now it's a little harder to clock needing a bit more voltage. Well...anyway the results of my 3 boards are as follows (all using 3.2Ghz @ 1.168-1.232v cpu)

ASUS M3A32-MVP
2.8Ghz @ 1.26v Prime stable
3.0Ghz tests fine, but didn't try for prime stable past 1.35v (boots 1.25v no problem)

ASUS MA78T-E
2.2Ghz @ 1.075v
2.4Ghz @ 1.100v
2.6Ghz @ 1.160v
2.8Ghz @ 1.260v
3.0Ghz @ 1.370v (boots @ 1.25v as well, again didn't test Prime95 just wPrime and SuperPi 32M benching)

Gigabyte MA770T (current temp board)
2.2Ghz @ 1.075v
2.4Ghz @ 1.150v
2.6Ghz @ 1.200v
2.8Ghz @ 1.270v
3.0Ghz @ ...1.400v just to get into windows and run! O__O

The only board I've used that has had any NB clocking issues was the Gigabyte, but it's an $80 budget board so that's expected although the board is awesome! My chip is a Phenom II 955 C2 stepping model using air cooling as usual. Tested with Xigmatek HDT S-1283 and Cooler Master V8 (both lapped as well as the processor). I'm not sure which board I'm going to go with for the next one just yet, likely it'll be the Crosshair III but I'm enjoying this 770T temporary board a lot!

Kei

[I.nfraR.ed]

Very good CPU-NB, Kei I just tested the one on my 955. I might be having issues with this Gigabyte MA790FX-UD5P in clocking CPU-NB. My old Asus M3A78-T seems better for that,
I will check with the first 965, which easily made 3000MHz stable on CPU-NB with 1.45V on it.

Prime stable
2736 1.3V
2808 1.325V
2860 1.4V
2873 1.45V
2886 1.525V
2899 not stable with any voltage

[Lastviking]

Very good CPU-NB, Kei I just tested the one on my 955. I might be having issues with this Gigabyte MA790FX-UD5P in clocking CPU-NB. My old Asus M3A78-T seems better for that,
I will check with the first 965, which easily made 3000MHz stable on CPU-NB with 1.45V on it.

Prime stable
2736 1.3V
2808 1.325V
2860 1.4V
2873 1.45V
2886 1.525V
2899 not stable with any voltage

Hmmm

2800 1.25v easy for me but after 2800mhz its very hard...2850-2900 1.3v-1.4v no go. Will test more later.

[FlanK3r]

lastviking: good, with 1.25V its great! How is your NB voltage (not cpu-nb)? I need 1.35-1.375V up 2800Mhz

[Lastviking]

lastviking: good, with 1.25V its great! How is your NB voltage (not cpu-nb)? I need 1.35-1.375V up 2800Mhz

Auto...i will try more when i get my new board.

[SocketMan]

The main thing that stands out when you go through all the clocks through the forums is:

Why the bloody hell didn't AMD spec a 2.4Ghz CPU-NB frequency to start with?!

They did for the 6 core Opterons (24xx).
Phenom 2 (still needs to) run on the older AM2 boards, with no separate
power plane for the CPUNB - that's probably why.

[SocketMan]

They did for the 6 core Opterons (24xx).
Phenom 2 (still needs to) run on the older AM2 boards, with no separate
power plane for the CPUNB - that's probably why.

I forgot that the HT link (system bus) is higher then NB on the Istanbuls;
so it's 2400mhz (4800 DDR) for the Hypertranport and 2200 for the NB.

http://products.amd.com/en-us/Optero...&id=553&id=568

[mongoled]

Got bored... is prime96 blend enogh to test stabilty on the IMC/NB?, i wonder one thing has the memmory clocks any impact on stabilty on nb/imc? higher memmory clocks lower nb clocks?

Yes, I think this would be the case, once I have some free time I will check this.

But it would make sense that the CPU-NB would be stressed more with the memory running at higher frequencies.

Thanks for all the posts peeps, this is great.

Now people can come here and get a clear idea of what voltages people are running to achieve said overclock.

[memel]

PII 965 0952 - NB 3000Mhz 1,40V
Asrock AOD790GX

[wez]

Yes, I think this would be the case, once I have some free time I will check this.

But it would make sense that the CPU-NB would be stressed more with the memory running at higher frequencies.

Thanks for all the posts peeps, this is great.

Now people can come here and get a clear idea of what voltages people are running to achieve said overclock.

Tight timings and high freq will indeed stress your IMC more.
Cinebench is cool for quick stability testing. Prime95 blend, and four threads of memtest (hci design) is nice when you want o make sure the rig is up for 24/7 usage.

[etoManiak]

I got 3000 NB at 1.475V. Stable enough for some 1M's, 32M's. But momentally reboot after few second Prime blend start. Even at 1.55V i get BSOD after few seconds.
2800 NB even at 1.375V more stable, Prime dont BSOD, dont reboot, but CPU#1 always FATAL ERROR (rounding). (Other tests shows that its weak Core in my CPU)

P.S. I got 4Ghz at stock voltage stable enough for some 32M. But Prime didn't BSOD/reboot only with more then 1.475V. (Weak Core error)

[Sharptooth+]

I'm running my NB Freq at 2600@1.2v with Phenom II X4 955 at 19x200@1.4v ~3.8GHz. Super_Pi 1m and 32m stable.

[EvilBlitz]

CPU 3600mhz NB 2800mhz. Both 1.45volts. Air Thermalright extreme 120.
Have been running this from day 1. Needs more than 1.43volts for the NB to get that high. I didn't test too see how low I need it but it would crash at 2700mhz with 1.43volts fairly quickly. I could possibly lower CPU voltage if I tried but it is stable and has never crashed on me since I settled at those settings.
Never done any real stress testing but 4-5hour sessions of TF2 don't make it flinch so it is good enough for me.
Have changed from an Asus M3A78-T with 2x1gig DDR2 800 4-4-4-12 to a Gigabyte MA790X-UD4P and 2x2gig DDR2 900 at 4-4-4-12(slots 3 and 4 as well since the HS blocks slots 1 and 2 for tall mem sticks). Has run the same in both boards, no noticeable difference.

[FlanK3r]

I tried yesterday max NB clock with ambients and i got about 3070MHz for superpi 1M. If i tried about 3100 MHz, PC crashed...

[Cheffy]

release week 940 - 2500 NB with 1.35v 2600 only posts with 1.55v - but wont even pass the torture of loading memtest cd!

fyi - I notice that when nb is clocked to high, or core volts to low winrar benchmark starts to turn in very low scores while rest of windows is ok. firing up prime usually results in hard reboot. - perhaps worth charting your winrar scores as you wind it up, once they start falling, you know your past a limit and can act without getting a crash.