need help OVERCLOCKING 8600GT

[kooki]

i got an XFX8600GT 512 ddr2 and i wanna overclock it a little. im new to OC'ing.
stock- core clock-540. memory clock 400
when i change the clocks using ntune to anything above 620/450 the system crashes. why is that? what else do i have to change in ntune? never done this before. PLEASE HELP.
my cpu is q6600 and mobo is DG31PR. why cant i overclock it to about 700/500 and keep it stable? it crashes if i increase it by 50mhz.

[asingh]

Hi Kooki,

Overclocking is not that difficult...but you got to be really really carefull and follow some basic rules.

1. Be carefull -- OC'ing can burn out your card. Damage hardware.
2. Tweak the setting a bit...and test it for 15-20 minutes.

Use ATI Tools (works perfect with nVidia card) or RivaTuner. Tweak and TEST, Tweak and Test.

Am in office (will give you a more detailed procedure..in a couple of hours). If your system is crashing..that is not good. Your not overclocking correctly.

[hellgate]

@kooki do u hav a good quality psu buddy?

Use RivaTuner by the way

[MetalheadGautham]

1. Get a good PSU. what do you have now ?
2. XFX 8600GT is too hot, thats the problem.
3. You should have gone for 256mb GDDR3 instead of 512mb GDDR2. Its actually FASTER. And better.

[asingh]

From where I left off....

Points to consider before Overclocking (OC'ing)....

1. Have a good power supply -- one which is a bit over quoted as per your system requirements.
2. Your card should have an excellent cooling solution. Not sure what XFX8600GT has..? To verify this..monitor the temperatures using Rivatuner. It should not go above 80C - 85C under full stress. (Though nVidia 8xxx series are good cards..and can sustain higher temperatures, better to be safe). If cooling solution is not good..mount an after market cooler. Something like Coolviva Pro SE (Rs 1800) + good thermal gel. Removing the original Cooling solution will VOID all warranties.
3. OC'ing can void your warranties.
4. Be patient while OC'ing takes couple of hours--to hit the optimal, safe threshold.
5. No two cards (even if same OEM and type) will ever have the same threshold. So you cannot always compare two OC'ed setups/cards, to each other.
6. OC'ing will NOT give you drastic improvements in performance. Will just enable you to extract the maximum possible throughput vs the original factory setting. Probably a gain of 5-8 FPS.
7. Once you re-start the system the clocks will set back to default. (Unless you flash the BIOS -- but that is a more complex method -- will not get into that)

Background:
A gfx card consists of three main processing regions. Core Clock/Memory Clock/Shader clock. All three can be tweaked as per the user. In the method below..Core clock and memory clock will be tweaked and the shader clock will be automatically increased. (Which is bound to the CORE clock --- memory clock is independent).

Prerequisites:
1. ATI Tool.
2. RivaTune.
3. Latest Forceware drivers.
(let me know if you want the links for the above mentioned)

Method:
1. Turn off all extra activity on your system. Downloads, graphic rendering applications, internal/external LAN, music, excel, word. Keep the processor free. Since it sends/receives data too the GPU.Keep a native basic OS environment.
2. Launch ATI tools.
3. DO NOT use the FIND MAX buttons. Can ruin your card.
4. Using CORE and MEMORY toggle buttons move the units up. And click SET CLOCK.
5. First increase the CORE by 10 (will change the Shader too) and click on SCAN for Artifacts.
6. Run for 10 mins. If no artifacts then..
7. Increase Memory by 10 units and scan for artifacts again for 10 mins.
8. Keep repeating in increments of 10.
9. Once you start getting artifacts -- you have hit the threshold.
10. Decrease in steps of 2 or 5 repeat artifact study. (This time run tests for at least 20 mins).
11. Once you hit a stable threshold save the profile. (At times you might get a system crash/or hang..again this means..you have crossed the threshold). Re start and run test below the previous value.

KEEP A MONITOR ON THE TEMPERATURES AT ALL TIMES. GOING ABOVE 85c IS RIKSY.

When ever you log - in to the system, the card will be at normal state. Leave it like that. Only when launching graphic intensive applications "load" your OC'ed profile using ATI tool.

This should keep your card safe, and get you a good OC limit.

Best of luck..be patient...enjoy the extra FPS.