Hey all. Im running an Athlon64 3500+ Winchester with a nice big thermalright XP120 on it, iv got an Abit AV8 3rd eye and 2*256MB Geil PC3500 CL2 RAM. I have no problem overclocking a bit (to 2500MHz or so) but then things just seem to fall apart and I cant seem to get round this The best i can get is 232*11 bus @ 1.6V. RAM at 2.7V NB at 1.55V HyperTransport at 1.25V SB at 2.5V. AGP/PCI bus locked at 66/33 MHz. Iv got a lot of mileage in my voltages and things dont run that hot at these settings, but I just can't seem to get anything to run stably for more than about 2 mins at these settings. I know 232 FSB is more than my RAM is rated for, but iv dropped the latencies and it seems to do fine, as far as i know. So, any ideas?
iv tried putting some voltages up but it didnt make any difference :S the prob is i dont know which voltages are likely make it work. tis a bugger not being able to raise the multiplier
as said, got a thermalright xp120 with a YS-Tech 120mm fan on it. 2x80mm, 1x92mm fans exhaust and 2x80mm, 1x92mm fans intake.
IDLE: cpu: 25C (31C oc'd) nb: 26C (26C oc'd) pwm: 28C (32C oc'd) LOAD: cpu: 37C (47C oc'd) nb: 26C (26C oc'd) pwm: 31C (33C oc'd) these dont seem too hot to me (my old AXP 2000+ ran waay hotter and was stable)
temps arent high. if you can bump your core volts up more maybe?it could be that your set up is unable to clock more.
ok, well iv managed to get 2.6GHz. I lowered the multiplier to 10.5 and used 248MHz FSB. I had my RAM timings looow and my CPU voltage about 1.7V RAM voltage at 2.8V (maximum) and hypertransport at 1.3V This worked long enough for me to run SuperPi, and it worked! unfortunately, as I finished the test in record time, it crashed I tried these same voltages with normal multiplier for 2.5GHz and it's still just as unstable. Maybe just the RAM cant take it? Its only rated for 217MHz@CAS2 so maybe 232MHz or so is a bit too far, even at CAS3.
Stick your ram on a [166] divider (theres no performance hit using a divider on A64s) and change the multi to 10. Work your way up from 250htt. At 250htt your mem should be at 200mhz, so atleast its not slower then @ stock. When you start to get unstable, and more CPU voltage doesn't help (Give your ram some more voltage and play with timings to make sure it not your ram thats being limited), then try going for a lower multi and higher HTT to obtain faster memory speeds. 1.7v is a bit much for extended use. I'd recommend staying strictly under 1.65v on air, with load temperatures under 50*c.
Nice one, I'm liking that idea. Ill have a go tonight an report back EDIT: Right, I had a go. Some success, but not much. Under those settings my RAM seems fine, but things are still very unstable. Setting the FSB to 250 or over crashes the pc instantly (from windows) or stops it booting (from bios). Between 2.5 and 2.6 GHz I get about 30 seconds of operation before either my whole screen freezes, or things freeze but my mouse still moves With 10.5 multiplier i got the furthest, but it still didn't last long. When poking around in the bios i found LDT multiplier. is this to do with hypertransport? like FSB*LDT multiplier = hypertransport speed ?? if so, is it worth dropping the LDT from 5x to 4x to see if this makes things more stable? Dunno about anyone else's experience, but im wondering if the K8T800 Pro just isnt that good an overclocker. Either that or i expected too much
ah forgot about the LDT yea set that to 3x. .. or 4x if you can get that stable, but theres no performance difference anyway.
i've got the same mobo and processor as u, just with a GB of ram(look in sig), use the uGuru software to push it.
yea i do use the uGuru stuff, but some stuff you can only change in the bios. I'll have a go changing the LDT and report back
weyhey! LDT solved all stability problems! Seems the AV8 just doesnt like the hypertransport running above 1150MHz or so. I can now hit 2.7GHz with ease, and much lower voltages Thanks all (and esp TMM), any help was much appreciated
