Overclocking GTX480 sli

[chriso132]

Hi, i overclocked my 480's yesterday on stock cooling, the max i got was 850 on the core clock and 2100 on the memory clock. There was a lot of graphical glitches though so i eventually worked out that the best balance was about 810 on the core clock and just stock on the memory clock. This was my first graphics card overclock. Its maxing at about 72 degrees under load with heaven benchmark and im getting about 55 fps. 850 on the clock was only getting about 2 or 3 fps more. Is this ok ? is it safe to keep my cards overclocked at 810 on the clock ? and is there anyway to get rid of the glitches or artifacts i think there called =p when using a higher clock.

Thanks =)

 

[RavenXXX2]

Did you give it more voltage at 850 core?

TBH 480 SLI is beastly enough with no oveclocking, I would settle at 810 core and yeah as long temps stay below 95c, should be fine.

 

[chriso132]

didnt have the option to, im not sure where i get the msi afterburner version with the option to overclock the voltage.

 

[chriso132]

Even at that, i dont think its worth the extra couple of fps for about another 10 degrees.

 

[iB CoMpL3XiTy]

810Mhz Core clock seems very respectable. When you start to get aftifacts its usually because the overclock isn't stable and needs more voltage to become stable, or the GPU is gettings too hot.

I would recommend you load up GPU-Z (Freeware), install it and go to the 'Sensors' tab, here you will find temperature infomation for the graphics cards Core, memory chips and VRM (VDDC) chips.
Then load up a program like Furmark or MSI Kombuster (designed to apply maximum stress to graphics card(s)
Run the program for 30Mins and see if there are any artifacts, if so then you know your overclock isn't stable and/or your graphics cards are getting to hot (In which case either reduce the overclock or apply a small bump in Vcore and test again)

Monitor temps with GPU-Z, I wouldn't let the Core go above 95C, I wouldn't let the Memory go above 95C and I wouldn't let the VDDC's go above 110C.

MSI Afterburner will allow you to adjust the Core voltage for your graphics cards.

 

[RavenXXX2]

Use the latest MSI AB you need to go in to settings and unlock voltage control, my 480 runs at 850 core @ 1.075v as shown in AB, check what your default core volts are and raise them to 1.075v and test for stability.

 

[chriso132]

Whats your memory clock at raven and ill try the same settings. is this completely safe to run at if the temps are ok ?

 

[RavenXXX2]

1950 for memory, gains are negligible when clocking the memory on a 480 and it can destabilize any decent core clock so I leave it low.

If temps are fine it's OK, 1.075v is the max safe volts for a 480 recommended by Nvidia, so its fine.

 

[chriso132]

ok thanks ill try those settings, whats your temps at whe running furmark ? and is that stock cooling ?

 

[subbytna]

Use the latest MSI AB you need to go in to settings and unlock voltage control, my 480 runs at 850 core @ 1.075v as shown in AB, check what your default core volts are and raise them to 1.075v and test for stability.

the guy has SLI 480's surely there isn't a game that he can't max out the settings with 2 of them? Does he need to OC...or is it just for e-peen

 

[RavenXXX2]

Stock cooling and I don't run furmak, it's way over the top and not always a good indicator of stability, test stability with games or benchmarks like unigine heaven. In heaven I max out at 80c.

 

[Speedy Pete]

But its like having a w12 engine without the turbo's! of course he needs to oc !

 

[chriso132]

subby i know what you mean. im just wating to see what i can do with them. Maybe use the settings when benchmarking.

 

[chriso132]

Aye, pretty much what speedy says =p

 

[Razor Time]

the guy has SLI 480's surely there isn't a game that he can't max out the settings with 2 of them? Does he need to OC...or is it just for e-peen

It depends on what game you are playing and res. Metro and Crysis (16xQAA and TRSAA) run my 480's upto 80% gpu load with vsync on and a clock speed of 890Mhz/2150 @ 1080p.

All other games don't need the cards to be clocked at all.