My AMD Opteron 165 OC on Asus A8R-MVP

[Admiral]

I forgot to mention it was with a single core, winchester 3000+ CPU

[borat]

k, maybe someone would explainn why I got an extra 5fps in Dooom 3 simply by running the HT link at 1112MHz (x4) instead of 834 (x3) on my previous VIA K8T800 Pro motherboard
(CPU fsb @278Mhz)

Can't say for sure what the gains are down to with your set up but if you take a look at the numbers here they keep all things a constant except for the HTT bus and take the multiplier down from x5 to x4 and x3 in the benchmarks chart - no significant performance hit at all.

http://www.insanetek.com/review.php?id=10

Seen the same when i have benchmarked my machine - I do have the same motherboard as the review though, may be different on a non-nvid chipset.

There is zero benefit to lowering however if you have a stable set up, the general rule of thumb is do not run it much past 1000Mhz. Mine is ok to about 1100 Mhz without being unstable. To be sure always keep it under 1000Mhz when testing your overclock and you can be certain its not the HTT thats going to give you problems.

[borat]

Maybe i should have clarified what i'm trying to say before opening my big mouth

There is a small hit on performance when lowering the HTT multiplier but in most cases it boils down to 1-2% at most. If you are overclocking then you should take the HTT down to 3x, find out your max O/C and then if possible move the HTT up to 4x.
if you are overclocking the HTT below 210-220Mhz set it to 5x, below 260-270 then set it to 4x and anything over 260 set it to 3x. The exact cut offs depend on how much above 1000Mhz is stable for you.

The bottom line is that you will get way more performance with a decent O/C at a lower multiplier than compromising your O/C and sticking to the highest multiplier.

*note to self* - Read your links before you comment on them !!!

[Kooldino]

So I can lower my HTT to x3 when I get home tonight, and my RAM/CPU speeds should all be intact, correct?

If so, i'll do before and after benchmarks.

[Marshmallowman]

Not that it makes difference but it seems that ati chipsets can tolerate a lot higher HT speeds, whereas with nvidia chipsets 3x seem to be the most stable.

But keeping it around 1000mhz would probably be a good idea anyway

[borat]

So I can lower my HTT to x3 when I get home tonight, and my RAM/CPU speeds should all be intact, correct?

If so, i'll do before and after benchmarks.

correct, RAM/CPU should be intact.

[Kooldino]

I ran it at both last night. Made zero difference in the CPU Arithmatic test. I'll try other tests in the future.