Looking at the spec sheet, yours are rated for 9-9-9-24 1.65V
I'm sure you've heard again and again how our Phenom ii x4 955's IMC favors tighter timings over higher clocks. They also struggle with anything over ~1668MHz+ especially if all DIMM slots are populated. So, it might be beneficial for you to lower their speed down some, try tighter timings and see if they are stable. I'm guessing they can probably do 8-8-8-24 1333-1564 or so @1.65V. You should also bump the NB speed (and voltage a bit if necessary) up some. The stock of 2GHz really holds back faster ram.
This was my experience:
I'm running the same set except mine are the 1333 cas8 version. With everything left at default mine ran at:
Now those are the default settings for most motherboards (probably what yours run if you just stick them in and do nothing), and mine ran fine and stable at those settings. They scored a WEI of 7.6
I realized that the ram I chose was not the most overclock friendly, and probably wouldn't like going too high over 1333. So instead of overclocking with the ref clock I used the multiplier. My settings were:
Multi: x19.5 (3.9GHz)
Ref clock: 200 (if you bump this up it will increase your ram, nb and ht link speeds)
NB Multi: x12 (2.4GHz)
I left HT alone
I tightened ram timings to 8-8-8-24-34-1T
This increased my WEI ram score to 7.8!
In the Phenom II x4 955 benchmarks I've read 1333 performs nearly identical to 1600+, while 1066 is a big decrease in performance from both. That's why I think you're best off setting them to 1333 with 8-8-8-24 timings. Overclock the ref clock some and your ram will be bumped up with it. If that isn't stable then try just using the stock 9-9-9-24@1600 settings. Compare the two, see which gives you more performance.
Remember to use 1.65V for your ram otherwise they are more likely to be unstable.
Also don't forget to bump up NB speed and Voltage a little bit. These threads should help you with some good settings:
http://www.overclock.net/amd-cpus/50...-oc-550-a.htmlEdited by FDS - 12/29/10 at 2:05pm