OCing the 4800+

[eltce]

Hi, I'm new on these forums and I am more of a laptop user but my brother recently bought a socket 939 AMD 4800+ to replace his 3200+. He also bought the Zalman CNPS 9500 AM2 fan which looks like its made of alumnium but is copper and has green LEDs. Anyways, he really doesn't feel like OCing, but I told him he wasted his money on an external cooling solution if he doesn't OC. His temps for his 3200+ are in the low 20s with stock cooling and only go up to mid or high 30s. I have AS5 ready to slap on but I just need to know the steps to OCing. I couldn't find a sticky on here for a guide so can someone teach me. He has the Asus a8n32 sli motherboard. Also what temperatures are considered "high" for the AMD processor at peak loads. Is 40 high?

 

[myocardia]

40C is low/good temps for an A64 under load, assuming it's 100% load, like Prime95 or SP2004 will give you. If that's what it runs while gaming, that's a little high, but definitely not too high. That only applies to the single cores, though, since they run cooler. 40C while gaming isn't bad at all for an X2 4800, since it's running two cores, with twice the L2 cache for each core, and is running them at a 20% higher speed.

Here's how to overclock A64's: link.

 

[betasub]

:thumbsup: Good link. Should be compulsory reading for newbie A64/X2 overclockers.

 

[eltce]

Ok, I finally got around to OCing the 4800. Started increasing FSB by 5 mhz til I got to 225 which wouldn't boot to the OS. Went down to 220 and can only get 2.64 ghz. It peaked at 45C using torture test with prime 95. When I installed the processor, I used AS5 and the AM2 zalman cooling fan. I upped voltage from 1.400V to 1.425 and was able to push FSB back to 225 for 2.7 ghz. However, the voltage increase substantially increased temperature as it hits 54C. (A 9C raise for a .025V increase). My question is, are these temps normal for these speeds and should I up the FSB even more. To me, it seems to be that the voltage and not the FSB is the determining factor for the load temperatures. Should I just keep increasing the FSB until I find the max on 1.425V or should I just run it at 2.64 ghz at 1.4V? Do you think its possible to get 2.8 ghz on 1.425V? Also is it true that the multipliers are locked for the x2 cpus so 12x is max for 4800+ while the multipliers for FX cpus are unlocked?

 

[txtmstrjoe]

Originally posted by: eltce
Ok, I finally got around to OCing the 4800. Started increasing FSB by 5 mhz til I got to 225 which wouldn't boot to the OS. Went down to 220 and can only get 2.64 ghz. It peaked at 45C using torture test with prime 95. When I installed the processor, I used AS5 and the AM2 zalman cooling fan. I upped voltage from 1.400V to 1.425 and was able to push FSB back to 225 for 2.7 ghz. However, the voltage increase substantially increased temperature as it hits 54C. (A 9C raise for a .025V increase). My question is, are these temps normal for these speeds and should I up the FSB even more. To me, it seems to be that the voltage and not the FSB is the determining factor for the load temperatures. Should I just keep increasing the FSB until I find the max on 1.425V or should I just run it at 2.64 ghz at 1.4V? Do you think its possible to get 2.8 ghz on 1.425V? Also is it true that the multipliers are locked for the x2 cpus so 12x is max for 4800+ while the multipliers for FX cpus are unlocked?

I'm playing with my X2 4400+, which is basically identical to the X2 4800+ except that the 4800+ has a maximum 12X multiplier (the X2 4400+'s multiplier tops out at 11X).

Non-FX series CPUs are max-multiplier locked; you can't go up with the multiplier setting, but you can go down. FX-series chips are completely unlocked.

Presently I'm @ 2.543GHz with my X2 4400+ (242 x 10.5) CPU-Z validation. Vcore is @ 1.425V, which is already a little higher than stock (1.4V), and I've got the same Zalman cooler (CNPS9500 AM2). My peak load temps are circa 49 degrees Centigrade.

I'd say you've already got a pretty good overclock on your 4800+ to get to 2.7GHz. All other things being equal (which they aren't), what probably accounts for your higher overclock than mine is that I've got an inferior stepping. At this point, I don't really want to push my X2 4400+ with more voltage at the moment just to exceed 2.543GHz.

But who knows how I'll feel tomorrow! ;-)

 

[loafbred]

>>Went down to 220 and can only get 2.64 ghz. It peaked at 45C using torture test with prime 95.<<

You need to run two instances of Prime 95. Create two shortcuts to your desktop, and set the affinity for each shortcut to the two separate cores. You'll have to search for the instructions to do this, as I don't have them handy. Expect load temps to jump from the 45*C that you're getting while sharing the load between the cores with only one instance running, to something in the neighborhood of 60*C with both cores running at 100%.

As a disclaimer, I have no idea how running two instances of Prime 95 translates to running the software that you actually use now, or will run in the future, but I think it's safe to assume that, at some point, you'll fully load both cores, at least for short periods of time.

With that said, you'll need the absolute best air cooling available (large, heavy, expensive and unbelievably loud) to run that cpu with higher-than-default voltage, and don't expect to use more than 1.45v. A good water cooling setup can deal with it much better.

 

[ScrewFace]

Forget Prime95. Get Orthos. It automatically checks for dual cores and, if found, will also automatically run on both cores.