Computer locks up after overclock

[rrcn]

I have read where some people were able to overclock their Athlon 2500+ to 3200+ . I have never overclocked before, but recently I gave it a try. I got the FSB to 179MHz, but once I clock it to 180mhz, the computer locks up. I was watching the temps as I was increasing it 1-2Mhz at a time and they were about 44C at 179Mhz. I am using the EasyTune Wizard that came with the board to overclock it. Also, the AGP and PCI are not loackable. I would like to know why my computer locks up and how I can overclock it past 179mhz (if I can) without having to change the stock hsf?

XP 2600+ Barton 333fsb
Gigabyte GA-7VT600-L
512MB PC2700 2.5-3-3-6

Thanks in advance.

[Buzioid]

It's not just the heat the causes it to lock up, it's also stability. One megahert can be all the difference between stable/unstable.
I haven't used easytune myself, but I would overclock in the BIOS utility instead of side windows. It might effect it, but I'm not totally sure if it will under Windows.

[thekingofpain]

Your AGP and PCI bus will be WAY out of spec before you reach the limits of your CPU or chipset---a different board is your best option to go forward unfortunately...

[rrcn]

I tried it through the BIOS and it did the same thing except that time I had to clear the bios. Through easytune you have to set it to automatically overclock on the next reboot which is why I dont use the bios.

[Edit] So the reason for the locking up is the PCI and AGP being out of line?

[rpertusio]

Agreed... overclock from the BIOS.

A few key components in overclocking limitations:

(1) Core voltage - The higher the voltage, the more stability you have.. and the higher you can overclock. However, increasing core voltage increases the heat output considerably! For starters, take your Core Voltage and bump it up by 0.025v or 0.050v and see if the 'lock ups' go away. Keep an eye on your temperatures (although 0.050v shouldn't push your system out of temperature range.)

(2) The wrong memory timings/settings will cause headaches in overclocking. If you increase your FSB, you increase your memory speed as well. If your memory isn't designed to handle these higher speeds, then be wary! You may need to ease up on the memory timings. Memory timings (such as RAS-to-CAS, tRAS, etc) should be bumped UP. Higher numbers mean slightly slower memory response... but that should help you decrease the effect that the memory is having on your overclocking attempts.

(3) As mentioned earlier, your chipset/PCI devices are also being overclocked. If your processor is unlocked (either on the chip or by the motherboard), you could raise the Multiplier instead of the FSB. (Increasing the multiplier will bump the speed in large amounts. Only bump it 0.5! You may in fact want to *lower* your FSB speed, in order to get a higher Multiplier)

- rp

[edit: fixed voltage numbers]

[Gettinbye]

I have the same issue with the GA-7VAXP board (with a 2800+). Same FSB lock up as well...at 179fsb it does fine, but at 180mhz it bumps up the pci/agp...that's when I hit the wall. There is supposedly a "hacked" BIOS for many Gigabyte boards that allows splitting the PCI/AGP bus, but I have yet to find it (other than mention of it here and there). I've played with the voltage as well and only succeeded in frying a card. If you manage to do it, I'd appreciate it if you'd post back with details on how you were able to manage it. AFAIK, the Gigabyte boards are not great O/Cers, but they are VERY stable...

[rpertusio]

I should also mention.. there are sometimes certain frequencies that a board doesn't like.

For instance, 178mhz works fine, 179mha locks up, and 180mhz works fine. Try 'skipping' over a frequency that you are having problems with, and see if it 'magically' goes away.

- rp

[rrcn]

rpertusio - my multiplier is locked and what do each of the memory timings mean? how would I know which one to bump up and what each one does? I'll also try skipping over 180mhz and see if anything different happens. BTW, thanks for the tips.

Gettinbye - I'll look around for the hacked bios and I MIGHT give it a try, not sure. How high did you set the voltage when you fried the card?

Any other suggestions would be greatly appreciated. Thanks all.


[Edit] - I noticed that on EasyTune that there are two setting modes for the DRAM, AGP and PCI settings: Divider and Linear. What is the difference between the two? I checked the help and it doesnt explain what the difference is.

[Gettinbye]

Originally posted by rrcn
How high did you set the voltage when you fried the card?

It was the first .5 that did it...perhaps just a weak card, but I decided it was time to quit playing with the O/Cing until I learned a little more about it

*EDIT* What version of EasyTune? Sounds like that might be the "splitter" I was looking for. I'll check it out. TY

[rpertusio]

Originally posted by rrcn
rpertusio - my multiplier is locked and what do each of the memory timings mean? how would I know which one to bump up and what each one does?

You might find this article helpful:
KB63 - Guide to RAM latency

Also at the bottom of that article, are some links to other overclocking articles that you might want to read.

- rp