ok OC sacanner work in this GPU 
 
EVGA OC Scanner v1.3.0 - Released 7/16/2010

• OC Scanner is now available for all EVGA graphics cards!

• Bugfix: GPU temperature protection message box was reopened indefinitely leading to a stack of message boxes.

i fix the problen of the green spots it was the memory clock i pout it in 454Mhz and everithing is ok

Ok, good ..I always recommend to somebody that wants to overclock their video card is to go look at the EVGA Product Spec PDF's and try the clockspeeds of the next faster card, if it works ok then go to the next faster one, etc..Some cards will overclock good and some simply will not.
http://www.evga.com/support/specs/default.asp?fam=19
 
 

i gonna give it a look thanks for the recommendation

ok i have played with these cards abit and they are much more sturdy that 1 might think.
 
i have had mine at a whopping 92c while i was messing with it. i had it volt modded and also voltmodded the memory. it was at 900/2400/570
 
honestly i was impressed with the results but it didnt last long :(
 
ohh yeah temps :P 70ish is fine and you clocks wont hurt it that much. also there is no fan control for these cards. the fan only has 2 speeds. stop and go. if you want to make it cooler zip tie a 60mm fan to the heatsink, that got mine down to about 60 with the above OC. i got it down to sub 50 on air but that took much more modding.