AMD 64 overclock

[leekirlew]

I want to increase the clock multiplier on my system, but the option is not avilable in my bios. Nor are any options to do with voltages for my ram. Is there a key I need to press to access advanced options or something? I think the bios is an ami v02.54.

Thanks

[cloasters]

Yo! Anyone using the same mainboard that leekirlew wants to OC?

[GrahamGarside]

I don't believe the clock multiplyer on A64's can be increased, it can be lowered thanks to amd's cool'n'quiet using a tool called cpumsr though (will find a link)

[netboy0440]

They can be overclocked easy. I have a 3500 at 3800 clockspeeds 2.4ghz and I can go a lot higher as my cpu is only 45*C at full load. These cpu's can handle 70*C

--Greg

[GrahamGarside]

they do overclock quite well, the fsb usually being the restricting factor. I've had my 3400 newcastle core running at 2.6ghz with the standard cooling that came with it pumping out over 70 degrees C of heat and I think it was my msi ms-6741 board that was letting me down

[DiabloAbogado]

I'm only able to get 2.23 (9.5x235) from a 2GHz 3200+ Clawhammer. Not sure what's holding me back. I have some type of protection on my board that won't post any higher. It sucks cause I'm water cooling my CPU so I know I have headroom. no matter if I have 4x multiplier and 1:2 mem divider, can't get HHT over 235. Still working on it tho.

[alexkerhead]

The a64s are not well know for overclock, not too say nobody got a descent o/c, but they are the best stock CPUs, not good overclcokers.

[Gizmo]

Actually, I think the Clawhammer cores are the worst of the bunch for overclocking. Some of the newer chips are actually doing fairly decent; nothing like what we are used to seeing with Barton cores, though (at least, not yet).

[DiabloAbogado]

Yes, but the newer cores all seem to have smaller L2 cache and I think that's the reason for the high speed rating and OCability.

[DiabloAbogado]

I did find out one thing tho on my MSI K8N Neo. If you have the CoolNQuiet turned on in the bios, you can't get over 235 on the HHT no matter what. I turned it off and now can get it to 335 before things get unstable. That's with everything else underclocked massively and 3x on the HHT multiplier. Don't think I'm going to go to 2x because I'd have to get to 450 for the bus to run near what it is at present.

Right now my mem is 1:1 at 235 (pretty good for 3200+). Does anyone know if I should use the divider to get a higher HHT? or will the performance drop significantly? I can't find out the answer to this anywhere else.

[leekirlew]

Thanks,
I've downloaded and installed a bios flash on my system, It now has the ability to change the multiplier and the v core.
I've tried upping the fsb to 210, but the system starts to randomly restart. Sometimes when I switch the comp on it loads the bios, but the winxp loading screen doesn't come on so I have to physically restart the comp. I don't know if the fsb o/c and the comp not starting correctly is related. My operating temps are 36 degrees C MB and about 43 degrees C cpu.
Secondly, now I have the ability to run the clock multiplier I can't o/c, only u/c as said previously in this thread. Would disabling cool n quiet solve this problem?

Any help appreciated

[DiabloAbogado]

Definitely disable CoolNQuiet. Don't know much about the SiS chipset, but my nF3-Gb has stability issues on the first two Sata ports so you might want to check that. I've looked around and the only thing I can find is that CoolNQuiet sucks on any board if you're gonna OC. For your board, might RMA if you can. I can't find anyone else having that kinda problem. Most people say 220-230 is the max for that board so not getting past 210 might be bad luck.

[DiabloAbogado]

I've found several articles saying that most CG Clawhammer CPUs OC up to 2.5 GHz on air. I'm not having that kinda luck watercooling and I have a CG ClawHammer.

And, to answer my own question from above. Running a divider on your memory shouldn't affect performance on A64s cause the memory controller in on-chip so it's already running at a divider. Makes sense cause CPU-Z always shows CPU/9 as the divider.

[leekirlew]

I'm just getting to grips with this whole business, how woul I check for errors on my sata ports? I do think it is some how related to this, at first i thought it was heat, then power maybe (400w psu, as in sig with 3 x 80mm and 1x 120mm case fans). But it seems that when the comp restarts, I take the side off the comp and wiggle the wires it starts fine, so I'm now thinking maybe loose molex connection. I've got a sata power connector in my draw which came with my system, should I be using this rather than the molex that came fitted with my system?

[DiabloAbogado]

Definitely use the sata power cable. I don't know how to check the stability of Sata ports. My guess is try OCing on different ports. You shouldn't have to reload windows each time, just make sure all ports are active and move the cable and try again.

[leekirlew]

OK thanks, I'll try that later (in the middle of a big download) and post how I get on.

[DiabloAbogado]

Just an update. my 2.0 GHz Clawhammer Rev CG hits 2.5GHz 10x250. Checking stability now, reboots at 255 so I'm not holding my breath for 100% stability @ 250. Disabling Cool-N-Quiet makes a helluva difference! Couldn't get past 9.5x235 with it turned on.

[alexkerhead]

Originally Posted by DiabloAbogado

Just an update. my 2.0 GHz Clawhammer Rev CG hits 2.5GHz 10x250. Checking stability now, reboots at 255 so I'm not holding my breath for 100% stability @ 250. Disabling Cool-N-Quiet makes a helluva difference! Couldn't get past 9.5x235 with it turned on.

Very Very nice for an A64..
a 25% increase is extremely nice for the cpu you have there..

[DiabloAbogado]

I have noticed, using ClockGen, that the memory speed changes based on the cpu divider, furthering the belief that the memory speed is a division of the CPU speed already. When using a 5:4 divisor the mem speed varies around 10 MHz when you change around the CPU multiplier. Definitely something to pay attention to when overclocking. Also. the bandwidth of the memory is a little odd according to Sandra. @ 9.5X235 with 1:1 memory, I get 3405MB/s. @ 9x255 with 5:4 memory (221 mem speed) I get 3426MB/s. Little odd.

[leekirlew]

was a no go, i'm running at 212 now and thats the max. Just tried 213 and windows rebooted as soon as it logged on. Any more suggestions? Could be the value ram that came with my system?