X2 3800+ Overclocking

[Dougiebabe2003]

Hi,

got to get post in before it crashes.

What is the max spped the above CPU should get to?

What are max temps?

And what should I believe, BIOS or CPUZ/Everest for DDR speed?

Cheers in advance, Doug.

EDIT: Also what should I be going for? CPU clock? RAM speed? Timings? FSB OC? Should I lossen timings so RAM can go higher? (do the X2's still like tight timings?)

Should I worry that the HT link isn't as quick as it first was?

Sorry for questions but having probs with it

 

[Will_3rd]

I've got mine up to 2.9Ghz, but each CPU is different

I usually stay in the 50-60 range to be safe

The BIOS and CPU-Z should usually tell you the correct speed.

All those you've mentioned can be tweaked, just tweak and you'll find what is best.

As for the HT you should try and keep it as close to stock as possible (1000mhz)

 

[jak731]

Gotten through 3 3800+ 939 cpus, because of the insanely low price of late and a couple of friends wanting one. First only did a pityful 2.5GHz before failing prime and super pi, second did 2.7 and the final one did 2.9. These where at 1.4v. The steppings of the first 2 where CCBWE, the last one was QCBWE (i think).

To get the max overclock i reduced the HT multiplier to 3x, the memory divider to 1/4(using a dfi board, you might not have as many dividers, i would recommend setting to 333 or 266 at higher clocks) and set the initial FSB at 240MHz, all 3800+ i've heard of will do 2.4GHz so this should be fine. Then use clockgen to up the FSB, run prime 95 on both cores and occassionaly run a super pi 1 million calc. Once i'd found the max i reduced the frequency by 50MHz and tried to find nice dividers with the memory.

Used voltage at 1.4v, not much above stock but gives a good bit extra headroom. I tried upping the voltages to 1.6 on the three above mentioned 3800s, one wouldnt post the other 2 only gave an extra 50-75MHz, which isn't worth the reduced lifetime/heatput.

Keeping the memory dividers low and the HT link low should mean that the first failure is due to the cpu's limit, not anything else, as long as your motherboard has a high max FSB and you know the limit of your RAM (if you dont then take its stock values).

N/B the FSB is locked to the main frequency of the cpu with a max multiplier of 10x on the 3800, this is what you want to get the most out of. It also locks to the HT which has a 5x multiplier, if left a 5x it will soon cause the cpu to fail, reducing it to 3x doesnt affect the performance to much, so its worth sacrificing. It also affects the memory, which works at 2x the FSB, as long as its below its limit it shouldnt cause a failure, if it goes above its limit while trying to get the max oc reduce its multiplier in the bios.

 

[Dougiebabe2003]

Gotten through 3 3800+ 939 cpus, because of the insanely low price of late and a couple of friends wanting one. First only did a pityful 2.5GHz before failing prime and super pi, second did 2.7 and the final one did 2.9. These where at 1.4v. The steppings of the first 2 where CCBWE, the last one was QCBWE (i think).

To get the max overclock i reduced the HT multiplier to 3x, the memory divider to 1/4(using a dfi board, you might not have as many dividers, i would recommend setting to 333 or 266 at higher clocks) and set the initial FSB at 240MHz, all 3800+ i've heard of will do 2.4GHz so this should be fine. Then use clockgen to up the FSB, run prime 95 on both cores and occassionaly run a super pi 1 million calc. Once i'd found the max i reduced the frequency by 50MHz and tried to find nice dividers with the memory.

Used voltage at 1.4v, not much above stock but gives a good bit extra headroom. I tried upping the voltages to 1.6 on the three above mentioned 3800s, one wouldnt post the other 2 only gave an extra 50-75MHz, which isn't worth the reduced lifetime/heatput.

Keeping the memory dividers low and the HT link low should mean that the first failure is due to the cpu's limit, not anything else, as long as your motherboard has a high max FSB and you know the limit of your RAM (if you dont then take its stock values).

N/B the FSB is locked to the main frequency of the cpu with a max multiplier of 10x on the 3800, this is what you want to get the most out of. It also locks to the HT which has a 5x multiplier, if left a 5x it will soon cause the cpu to fail, reducing it to 3x doesnt affect the performance to much, so its worth sacrificing. It also affects the memory, which works at 2x the FSB, as long as its below its limit it shouldnt cause a failure, if it goes above its limit while trying to get the max oc reduce its multiplier in the bios.

Cheers for replying guys!

I got it to 2.75ghz stable I think... Going to leave it testing overnight.

Finaly clock was 306x8.5 with 204ddr in the bios but only 198mhz in windows

Will be running quicker than his last clock of 245x10 though yes?

Cheers guys, Doug.

Edit: HT link is 306 x 3 = 918mhz.... Will that hurt performace? I've never really understood HT link etc

 

[jak731]

Cheers for replying guys!

I got it to 2.75ghz stable I think... Going to leave it testing overnight.

Finaly clock was 306x8.5 with 204ddr in the bios but only 198mhz in windows

Will be running quicker than his last clock of 245x10 though yes?

Cheers guys, Doug.

Edit: HT link is 306 x 3 = 918mhz.... Will that hurt performace? I've never really understood HT link etc

Looks pretty sweet, quite a high FSB though.

AMD doesnt seem to think that 1000MHz is limiting a 6400+, so i wouldn't worry. It basicly sets the peak data through put between the cpu and northbridge. Reducing it by 20% usually only results in a 2-3% performance loss. Eventually it would limit the performance severely but it would have to be set really low.

 

[wolvers]

Erm...sorry to sort of highjack this thread but I've got one of these running at 2.5ghz (250fsb+ram) and I can't get the HT to 1000mhz.
It's stuck at 750mhz (according to cpuz). The multiplier is set to 4x as well.
It's on an A8N32. Anyone got any ideas?

 

[Modjo]

Erm...sorry to sort of highjack this thread but I've got one of these running at 2.5ghz (250fsb+ram) and I can't get the HT to 1000mhz.
It's stuck at 750mhz (according to cpuz). The multiplier is set to 4x as well.
It's on an A8N32. Anyone got any ideas?

Had a 939 3800+ on a A8R-MVP mobo running at 2.7 (270x) on air. Was told to get the best o/c was to lower the HT to x3 (600) and to lower the memory to 200 or 266 (can't remember which now) as this would give a bit more headroom and as a result gave me quite a respectable o/c. 2.6 was stable on orthos for 36+ hours & 2.7 for over 12. Do a search for previous posts by me and it'll be one of the 1st threads I joined in on, it was answered by sum clever guys!!
EDIT: just found this link.....

http://forums.overclockers.co.uk/showthread.php?t=17749383&highlight=username_Modjo

 

[wolvers]

cheers for that Modjo. Some good info there.

I still don't understand why the HT link is 750 when the fsb is set at 250 and the multi is 4x.

There are some settings in the bios of the A8N32 that I'm not sure of though........

 

[Modjo]

No probs. I'm not sure on the HT speeds and what they should be either with regard to matching them with the 'other' speeds. I think we noobies need at least a an A-Level in applied science to work out some of the settings for overclocking!! I fluked my o/c with a bit of witchcraft and fairydust......

 

[wolvers]

I've said it before, and I'll say it again............thank god for whichcraft........no hang on that's not right..........?!