Hi guys, recently I bought a new configuration for my pc that includes a new one gtx 460 so I put it in sli with the old one. The sli works really well (around 140 fps in alien vs predator) but in some games like crysis warhead, crysis 2 and metro 2033 is hard to keep the 60 fps rate, the top card temp went up to 75c (which is good) and the case fans went crazy. I decided to overclock it just a little CC806, SC1612, MC1860 and I set the fan to 75% and it ran very smooth, the temps didnt go higher than 50c on the top card. My question is, should I keep the cards overclocked when gaming knowing that the fan is at 75% speed, or it will decrease the cards durability?, also I have a bad psu I dunno if I shouldn't overclock them, here are my specs:
Gigabyte 990fxa ud3
AMD Phenom II 955
Gigabyte gtx 460 1024 mb
EVGA gtx 460 1024 mb both running at 715, 1430, 1800 stock
thermaltake tr2 rx 750w :S
thermaltake v4 with 1 side 120mm fan and 2 upper 80mm fan.
I have the same cards in SLI and I run them at 800 core clock and i leave the fans at auto and I generally never see higher than 65c. Though I have an Antec 900 and good ventilation. Have had no problems with that setup and it runs great. I think you could even turn your fans down a bit if its loud and you will be fine.
You would have to keep an eye on the temps to determine what the overclock is doing to the cards , the greatest enemy to any silicon is heat and the cooler you are able to keep them the better. If when gaming your temps don't go over 50c them you should be fine. The side fan is a great fan spot to have a fan because it blows directly on the cards and if you can research somr different fans you could get one the has a higher cfm. I happen to think it's always fun to do modifications and when I look at my computer I see what I have put together and then I modify the case to suit my needs because when you but a case it is in a stock configuration and you may want to change just one thing to make it better. For example in your case I would have the two 80's on top , a 120 in the back , a 140 in the side and a 140 in the front. You could also take a 80mm fan and with some velcro mount the fan at the end of the two cards so as to blow directly between them towards the rear. So you see , there are always different ways to modify your case to suit your needs.
Why do you say you have a bad psu ?
According to hardware secrets it can't deliver it's labeled waltage, actually one must avoid getting beyond 600w, currently I'm aprox at 520w, I think I'll get a notua cooler to the side instead of the 120mm generic I've atm. Sadly I can't put any fan at the front 'cause the case seems stuck and I don't wanna force it. Thanks a lot for your repplies!
75C-85C is normal when the GPUs are in full load while gaming, above that you should start to worry about your cards.
Running your fans @ 75% will reduce the life span, but it will happen after a long time... so no worries but you should worry about the noise, i can't bear with my fan noise above 50%.
For the PSU, Thermaltake are known for their Toughpower series only anything lower than that have creepy reviews when going SLI or CF but i guess it's safe enough to deliver the required wattage for the 460s in SLI.
Temperature depends on a lot of factors, the most important is the ambient temp, also a good case with superior airflow allows the PC components to run cool and give you more headroom for overclocking.