OCing Athlon II X3

[TheStu]

I have this CPU:
Athlon II X3 425 Rana @ 2.7GHz

On this mobo:
ASRock M3A770DE

With this RAM:
A-DATA 4GB (2 x 2GB) DDR3 1333

Stock is 3 cores, 2.7 GHz. I currently have it unlocked to 4 cores, plus a 6MB L3 cache (no idea that would happen), and the RAM bumped to stock settings, so the CPU is at 3GHz.

13.5 multiplier.

I have tried searching, but it is a little tricky. I haven't OCed an AMD since the Athlon XP days, and back then it was dirt simple. But now I have all these different things in front of me, like PCIe/FSB Sync/ASync, Multiplier adjustments (is the multiplier unlocked?), VCore settings (I am not sure what the acceptable voltages are), and does the HyperTransport link matter?

I am not asking for a lot. This is my friend's new build, he doesn't want aftermarket cooling, so nothing extreme, but just a nice little bump. Can I safely get away with just altering the FSB, or do I actually need to alter other things as well?

 

[Axon]

Yeah, in general, all you need to do is bump the FSB little by little and then the CPU voltage, if necessary.

I don't think that processor has an unlocked multi, but I'm not certain. Some of the x3s become Phenom II chips IIRC.

 

[VirtualLarry]

Congratulations on a sucessful unlock.

Generally, AMD chips are multiplier-locked ("Black Edition" is the exception). That means that you have to increase the reference frequency ("FSB"). However, when you increase that, the HyperTransport and the memory frequency increase as well. So you generally need to drop those down, as you increase the FSB. HT multi is the setting to decrease the HT speed, and there are memory divisors to adjust the RAM.

Note that many motherboards express HT freq and memory multi in terms of what those frequencies would be at stock, rather than the raw multiplier value. So you might see HT of "1000", which would be a 5x multi (default for S939 chips). The newer Athlon II/Phenom II chips default to a max HT speed of 2000 I think, which would be a 10x multi.

There is generally no performance gain from increasing the HT above the CPU's default stock value. Only erratic behavior from the system if it's too high.

The Athlon II/Phenom II chips also have a NB (northbridge) multi, and voltage. Increasing the NB multi can increase performance too, but you will have to test for instability.

I don't remember which is which, but one of either the NB multi or HT multi has to be equal or greater than the other. Perhaps someone else can fill in the details. I haven't actually overclocked an Athlon II/Phenom II NB yet.

 

[busydude]

I don't think that processor has an unlocked multi, but I'm not certain.

Yes, the multiplier is locked. FSB is the only way to go. You also can bump the speeds of CPU-NB and HTT link for increase in performance.

Check this thread and this one

 

[TheStu]

Well, without getting too fancy, I suppose I will stick with just bumping the FSB. I have already noticed a synthetic increase, his PCMark score went from 6500 stock, to 9500 with the 4th core unlocked, to 10500 or so with the small bump to 3 GHz. Whether or not he would notice the difference between stock and OC/unlock is up for debate, but its fun.

 

[magomago]

wait i'm confused...i thought the FSB is gone with the introduction of HT....wasn't HT supposed to replace the function of the FSB by moving it on chip? Am i confused somewhere?

 

[Axon]

wait i'm confused...i thought the FSB is gone with the introduction of HT....wasn't HT supposed to replace the function of the FSB by moving it on chip? Am i confused somewhere?

Intel switched to BLCK speed, yes, but this is AMD.

 

[magomago]

Intel switched to BLCK speed, yes, but this is AMD.

I never said intel I thought with the original A64, AMD said bye bye to FSB.... So I'm completely wrong now lol? Geez what did I mix up..

 

[Axon]

I never said intel I thought with the original A64, AMD said bye bye to FSB.... So I'm completely wrong now lol? Geez what did I mix up..

You said HT, which I took as the acronym for hyper-threading - a part of Intel's current CPU line. But you meant something else. Hah.

Nah AMD still has a FSB. I have a 555 BE and it uses FSB and a multiplier to unlock.

 

[veri745]

You said HT, which I took as the acronym for hyper-threading - a part of Intel's current CPU line. But you meant something else. Hah.

Nah AMD still has a FSB. I have a 555 BE and it uses FSB and a multiplier to unlock.

The Ref clock isn't really a FSB. and HT in AMD-land stands for Hyper Transport.

But yes, bump the ref clock causes your RAM, NB, HT, and CPU freq to all increase unless you adjust their respective multipliers.

 

[TheStu]

So, for the highest FSB, I would want to keep the HyperTransport Link down to a lower number? How do all these things inter-relate? Where is the sweet spot?

One thing I never got into was RAM timings, the pursuit of the balance between RAM timings and FSB settings, so I only ever fiddled with the multiplier and FSB on my athlon.