System does not always post when oc'd? (4870 related)

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Vittra

Gawd
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Jul 9, 2005
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Not entirely sure if this should go here or in the motherboard section, but since this started when I switched over to the 4870 I figured I would put it here first.

So i've noticed after putting in my Visiontek HD 4870 that when the system is overclocked it refuses to post sometimes (Appears to slowly be becoming more frequent). It sits there, black screen, the monitor trying to decide between VGA and DVI before giving up with a black screen, all the while my ATI is screaming on and off trying to start the machine. This frequently happens when restarting the computer, in which case I need to shut it off completely and turn it back on. Sometimes, a reset from the switch will fix it as well, but not always.

This does not happen when everything is set back to stock, so i'm led to believe it is something to do with my OC. I suspect it might be the PCI-E Express Frequency, which I had locked at 100 back when I had my XFX 8800GTS 320MB. I've tried 101 and 102, but the issue got even worse (Had to do an actual reset - taking out the battery and switching the jumper for a few seconds).

The OC is pretty modest. E8400 @ 3.8ghz, 1.32Vcore, 2.1V Ram, PCIE Frequency locked to 100, rest of the settings stock.

Anyone had similar experiences? What could be causing this?

Everything seems plugged in fine.

System Specs:

XP 64 SP2 / Vista 64 SP1 Dual Boot:

Intel C2D E8400 / Asus P5K Premium / Seasonic M12 600W
(4gb) 2x2GB OCZ PC8000
Visiontek ATI HD 4870 512MB / 500GB SG SATAII 32MB (Vista 64 SP1) / 74GB Raptor (XP 64 SP2)
Onboard Sound / LG 16x DVD / Samsung T220 22" LCD
 
Yep, I had the same thing going on when I installed the 4870. I thought the card was dead at first and almost started going down the RMA road.

First power up with the 4870, the system (DS3/Q6600/3.2Ghz) would not POST. I put back the 8800GT and it POSTed fine. Put back the 4870, no go again.

Then I cleared the CMOS and finally saw it POST. Figuring it was fixed, I reset all of my BIOS options, rebooted and no POST again. I fought with it for a while like that, slowly increasing the OC settings (didn't get very far) until it crapped out again.

I was getting to the point that I thought the 4870 was just not gonna fly with other than stock system settings, which is of course unacceptable. :)

I figured before I give up I'd try falling back to older DS3 BIOS versions. I was running beta BIOS versions and I fell back to the latest official release and then everything settled down and the 4870 works fine at my normal OC.

Long story short..... try a different mobo BIOS version.
 
I knew I forgot to mention something. I actually have updated my bios already to see if it would fix the issue.. No luck. I was running the 504 Bios for this board (Asus P5K Premium, a P35). I did end up updating to the lastest one - 612, but still having the same problems.

Would be unfortunate if I have to switch motherboards due to this.
 
Vittra said:
I did end up updating to the lastest one - 612, but still having the same problems.
Click to expand...

There's no guarantee that the latest BIOS is the one you need to fix the problem.
Try falling back to older BIOS versions and retest each one.
Clear the CMOS after flashing each new version.
 
Uh oh.....

I'm having POSTing problems again with the 4870.
Apparently the BIOS rev. was not a fix.

Seems like it happens after the system is powered off for 6-8 hours or so.
It takes a CMOS clear to get the system to POST again.

This is with a DS3 and a PC Power & Cooling Quad 750W PSU, so it's not like it's a power issue or oddball equipment. No problems like this at all running an 8800GT.

Not good..... the 4870 is so nice otherwise. :(
 
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