Did I kill my A64 or motherboard?

[jhatfie]

I was fooling around doing some overclocking today on my A64 3000+. I've been running 2.5ghz stable for the past couple months at 1.76v, but I wanted to see what the max of the chip was at 1.82-5v. I am watercooled and my temps are respectable, never going over 45C even under prime at those voltages. So after doing some testing and the best I could bench (3dmark, superPi, etc) at was 2.55. No real improvement. So dropped the voltages back and changed everything back to my standard 2.5. Well I started playing some games and my screen all of a sudden went out. It was working, but no display. So I rebooted and the same thing happened after about 10-15 minutes. So I rebooted and ran Prime. Failed almost instantly. I thought that was weird, so I dropped it down to 2.4ghz and prime failed there as well, 2.3 too. 2.2ghz ran, but after about 5 minutes my display went out. I started at default settings and it ran fine for a while, but eventually the display went out again, but sound was still going through my speakers. I hit ctrl/alt/delete to shut down, but it wouldn't, it hung. I went back into the bios and noticed that my chipset voltage was at 1.92v even though it was set at default (which is 1.5 or 1.6v if I remember right). I am vcore and vdimm volt modded on my chaintech VNF3-250 so I am not sure if this had a affect on the chipset voltage or maybe the bios is off. So the weird thing is I can still boot at 2.5ghz fine, it is just when I run anything system intensive like prime or games that my system will lose the display or fail the application. My monitor is fine and it is not like when it goes into power save mode, it just stops getting signal.

So my question is what would be causing prime to fail now at speeds I've been totally prime stable at and my display to go out and freeze under system stressing applications. CPU? Motherboard?

[STEvil]

have you adjusted VBT?

[jhatfie]

VBT? Voltage by trimmer? Yep, I leave the setting is bios as default and use the trimmers to adjust voltage nice and slow.

[STEvil]

VBT is chipset voltage....

[Geforce4ti4200]

if you played with the vdimm volts then you probably damaged the cpu's ondie memory controller :(

[jhatfie]

Nope, I did not adjust the chipset voltage, but is showed up as running high in bios when I viewed the current voltages. It showed up at 1.92v which is fair amount more than it should be at default.

I did adjust vdimm, but only to 3.1v up from my everyday 3.0v. I adjusted very slowly and did not notice any voltage spikes.

[Poki]

If i were you i'd break out the multimeter and read the voltages off the board and see what's really going on. Something sounds like an IC is fubared.

[texuspete00]

Keep us posted... AMD says 2.9v is the most for vdimm but I was planning on 3.0~3.1v.... sounded reasonable enough to me. I think if your memory controller is done as toasty as has been known to happen, it wouldnt boot straight up so keep your head up!

[jhatfie]

Okay, so you want to hear something weird? I unplugged my computer and cleared the CMOS and left it overnight. This morning I plugged it back in and started to do some tests. Started at stock speeds. No problems. Started increasing the speeds step by step to 2.45ghz running superPi and quick Prime95 tests. My system froze at 245x10, but I had forgot to drop my HTT to 3x after clearing my CMOS and it does not like to run 4x with anything more than 235-240 HTT. Dropped it to 3x and now I have been running prime95 for about 45 minutes at 2.45ghz @ 1.68v with no problems. I am going to keep on testing.

[jhatfie]

So far so good. No problems other than my cat tripping my surge protector that my pump runs off so my computer shut down when it got to 60C (set up to do that). Freaked me out for a second. Otherwise I am running 250x10 again problem free. No more symptoms like before. Looks like disaster was averted. Think I'll drop back a little to 248x10 since I can do it at 1.728v prime stable and I'll feel better about it for the moment.

[bh2k]

I hate it when computers do that...

[Zeus]

I like cats.....



They taste like chicken. :D

[STEvil]

keep that VBT low..

[xxORBxx]

Originally posted by STEvil
keep that VBT low..
Why, what does the VBT do?

[STEvil]

Kills processors, whereas VDIMM doesnt seem to.

[afireinside]

VBT=chipset voltage? How high is to high?

[STEvil]

i'd say over 1.8, maybe even 1.8 is too high...

There are multiple people running 3.3-3.6v vdimm for months on end without problem, so i'm inclinded to believe vdimm has nothing to do with their deaths..

[xxORBxx]

Originally posted by STEvil
i'd say over 1.8, maybe even 1.8 is too high...

There are multiple people running 3.3-3.6v vdimm for months on end without problem, so i'm inclinded to believe vdimm has nothing to do with their deaths..
I think flucuating vdimm might kill it but thats just a thoery.