ACC and 45nm Phenom II's

[Dravic]

Thanks to Sylvanas and his Phenom II X4 955 overclocking adventure thread


I was stuck at 3.6Ghz until yesterday when i finally got my RMA ram back and was able to do some more tweaking. Google led me back here and to the thread above.

I know there is a belief that ACC doesn't do much for 45nm CPU's but it seems that rather then needing the ACC at -2%, 45nm Phenoms benefit from ACC at +2%. I haven't pushed any further to see if i can get 3.9 stable, but it was easily worth 200mhz for me.


CPU = 3800
NB = 2200
HT = 2200

CPU @ 1.475 (trying to get this lower, it was left over from me trying to get 3.7 stable without ACC on)
NB @ 1.43
NB VDD @ 1.23
HT link @ 1.32


OCCT stable for 1hr, will run longer maybe some other time.



1 bummer, I just cant seem to get my ddr3 1600 ram stable at anything above ddr 1333, I haven't tried again with the faster NB and HT so maybe I'll see if i an get that to work. If not I'll drop them from 7-7-7-24 to 6-6-6-?? for ddr 1333.

Was hoping for 3.8, was a little disappointed with 3.6 but it was such a big improvement over the 939 4800 @ 2.9 i was still happy. But thanks to ACC all cores +2% i'm at 3.8 now.

 

[Soleron]

2% what?

 

[Dravic]

ACC = Advanced Clock Calibration

Its an internal setting that can be adjusted on AMD Phenom cpus in order to acheive higher overlocks. It was originally thought to have no effect on 45nm version of the cpus (Phenom II).

The settings run from -10% to +10% in increment of 2%. It can be set individually for each core, or set for "all cores".

 

[Sylvanas]

Good to see my thread helped you Dravic .

I too found that +2% ACC definitely helped my 955 200mhz+, I have it set to +2% 'Per Core'. You may be interested to note that in a thread at XS it was found that 1333 6-6-6-24 1t is slightly faster than 1600 7-7-7-24 1t so if your ram is having trouble at 1600mhz don't worry, try 1333mhz. Keep at it and you'll get there, it takes some time to understand what settings are best and voltages etc- I still have post-it notes all round my desk with scribbled settings and voltages that helped me understand 955 overclocking. Once you get it stable perhaps try upping that NB, default VID is 1.1v for 955s 1.2v should get 2400mhz and 2600mhz can be anything from 1.2-1.4, I found it stable at 1.35v.

 

[willy3]

You might try maximumpc's website. June issue I think, ran mem tests with phenoms and intel cpus. Disappointing to me that memory doesn't seem to really add much kick; but, they tried it at different speeds and settings.
Still, running for the max, it all counts.