Quick Advice For GTX660 OC

[19Dan81]

Hey, everyone.

I would like to Overclock my 660 and I was going to do the OC through the Evga Precision Tool. Before I undertake the clock (bearing in mine this is my first experiment with OC) I would just like to make sure what I'm about to do will not harm my GPU in any way.

In the Precision Tool, I am going to adjust the Power Target from 100% to 110% and the GPU Clock Offset to +110mhz. I'm not going to alter memory targets or voltage - is this a safe OC?

Many thanks again, you guys are a wealth of information

 

[Netroxen]

Since you're new I'll elaborate on a very important piece of information that is commonly misunderstood regarding overclocking. Unless you're running some new-age bio-metric computer, under no circumstances will a GPU/CPU become damaged because of a high clock speed. The primary cause for a chip failing is because of excessive heat or too high a voltage being applied to the core. With that at hand, bear in mind that the 6XX series cards are all voltage limited to prevent damage being caused, increased amounts of RMA products and thus an increased loss to the manufacturer due to failed overclocks... While the voltage can be increased on the 6XX series cards, it works within manufacture specified limits. Therefore, overclocking the actual card is essentially fail-safe and won't damage it at all. So the next thing to take into account is the heat, make sure to create a custom fan profile in Precision X and ensure the GPU doesn't exceed 85c for prolonged periods, aim for the 65-70c mark. Even with that in mind, the actual damaging point is 120c, with 105c being the built-in shut-down temperature for the GPU. Unless you're running a stock release card, I wouldn't worry.

So yes, you're safe 98% - In Precision X, set your voltage offset to max (This will be 132% or 126% depending on the card) and increase the core/mem offset accordingly until you notice instability. Use Unigine Heaven/Valley to stress test the card.

Good luck bud!

 

[19Dan81]

Thanks for your reply. Very insightful and it's been taken on-board.

I was only able to up the Power to 109% at maximum and I stopped at +110mhz. This changed the default clock from 980 mhz to 1090 mhz, the boost from 1033 to 1143. Running 3dMark 11 and Heaven showed a 600 point increase in 3DMark and 12 point score increase on Heaven - so a 10% increase overall.

I didn't touch the Memory Clock offset - is this worth doing?

Thanks again for the time to reply.

 

[Netroxen]

The 6XX series cards increase the boost clock depending on the TDP overhead. So the card essentially overclocks itself according to its stability.
The offset is used to increase the clocks further above what the card does by itself.

The memory clock could be argued as the most beneficial to increase on the 6XX series because of the limited bus width. However a good balance of both should be good.

However ONLY increasing the core clock may yield negligible performance increases beyond a certain point, that's because the core and memory run in conjunction with each other, continually transferring and fetching data constantly.

The best way I can explain this is with a balloon.

Think of the neck of the balloon as the memory speed, now imagine that you squeeze the balloon to push all the air out. The higher amount of pressure being forced through the neck of the balloon would be the core clock. Now imagine that you enlarge the neck of the balloon and repeat the same process, the same pressure is applied however the air escapes faster because there is more room for air to escape. It's the same thing with the memory speed. At some point the core clock becomes obsolete because it simply can't be supplied with enough information to process at the speed the memory can supply it. Same thing.

So yes, it would be very beneficial to overclock the memory...