Athlon II X4 OC problem

[DrMrLordX]

I've seen this. I was testing how low I could put the voltage on my Athlon X4 620 (undervolting because it's summer and I don't want the heat). Prime95 still ran great with no errors, but the screen got all fucked up with a bunch of horizontal lines. All I was lowering was the CPU voltage. I did not touch any other setting; stock speed, stock memory volts, stock northbridge, stock everything. Yes it has integrated video.

Hmm! Fascinating. There's any number of odd things that could cause such problems. I've actually had graphics card/graphics card driver failures (and related crashes) due to overclocking which I fixed by raising NB and SB voltages, but never anything quite like that.

Turns out it's still not fully stable. It won't crash during game play or anything else I use this PC for anymore, it even passes AMD overdrive stability testing, but Prime95 still eventually crashes it.

For those who keep commenting it's a possible heat issue, I don't see how that's possible, it's 53C right now full load.

I'm assuming you have a C2 chip. Heck, this may even apply if it's a C3 chip: Propus hates heat.

NB stability plummets as core temps go higher, and you lose NB clockspeed ceiling as well. My Sargas (C2 stepping) exhibits similar behavior.

I'm stressing again, I bumped cpu vcore up to 1.475, Northbridge to 1.3V, and CPU NB is +.125. I'm positive it's a cpu problem and not a board/memory as it runs fine if I drop the cpu multiplier to 10X giving me a 2.5Ghz clock speed.

How hot does it run when you're at 2.5 ghz core speed? Do you lower your vcore when you run that speed?

Strange, but I've got it stable now for close to 5 hours in Prime, still going. The combination of dropping my ram multiplier down to 3.33 and having this jacked up Northbridge voltage seems to have done it. Really is a shame since it's stable at lower clock speeds with the faster ram speed. I really wish AMD would just release an Athlon II X4 BE, lol

Yeah, I'm thinking your NB just needed extra volts to be happy at those temps. Not sure about the RAM multiplier, but the IMC on K10.5 can be awfully particular about things. Since you have the 1:4 multi available, I guess that means you have a C3 chip?

 

[LoneNinja]

Mines a C2, bought it before C3 or even the 635 was released for that matter. My default northbridge voltage was only 1.1V, which seems low to me, would have sworn my Phenoms default is 1.2/1.3. Prime95 ran for around 8 hours and I decided to shut the computer off at that point, I'm going to try to get some of the voltages lower than what they're at right now.

When I dropped the multiplier to 10X giving me a 2.5Ghz clock speed, my ram was still overclocked, and with the northbridge voltages at default it was stable. I still had the cpu voltage way up at 1.475V when I did it, I left it there because I knew it would be stable. Once I changed the multiplier to 14x again to get 3.5Ghz, I had to bump northbridge voltage to 1.3, increase CPU NB by .15, and set CPU voltage to 1.5 while dropping my memory multiplier to 3.3 so it's running at 833mhz right now.

As far as I'm concerned this thread can be closed, I've got it stable and that's what mattered to me. Thanks for the help everyone.