how do i know, how much to overclock my gpu?

[gdon12]

I have the Gateway Official Site: Shop - Desktops – LX6200-01 Product Details - LX 6200 01 Product Details
I just recently purchased a new PSU and a new GPU 650 w corsair Newegg.com - CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 Power Supply - Power Supplies and a Newegg.com - SAPPHIRE 100259L Radeon HD 4870 512MB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Desktop Graphics / Video Cards 4870 512 sapphire radeon.
So the default has it on 750/900 and my fan speed is usually on at 50% when with the temperature at around 44 Celsius.
I tried on putting it to the maxed 850/1200 (with the fan being automatically controlled) but my Comp bugged out on me, and it turned to a blue screen basicly stating i need to restart, so i restarted doing it again, and i got artifacts and got the blue screen so i restarted again. I was a little hesistant on using it so i let it chill for about 10 minutes, and put everything back to default. My question is, how much can i overclock to? would it be possible to max it out again? and what should be my average Temp?
Also, when i maxed it out i let the fan get automatically controlled by the comp.

 

[Da Viksta]

you may have overclocked too much, trurn it down to a nice 850/1000 and work your way up....it may not be a temp issue but a power issue, you cant get enough power to the memory chips to get em to operate that fast....

 

[BongWizard]

woah woah woah!! slow down! there's no way you can OC the memory by a third with stock cooling... in fact, you'll be lucky to hit 1GHz with stock cooling... what you should really be working is the core

leave the memory alone for now and increase the core freq by 5-10MHz each time, testing for artifacts each time (ATITool is good, or you can just run the SM2 and 3 tests in 3dmark06)... when you do start to get artifacts, back the core down about 5MHz... this is gonna be your top core speed with stock voltage. now you can do the same thing with the memory

as for temps, the RV770s run quite hot... if you leave the fan on auto, it could get up to around 100C... if you decide to change the fan speed (which you should, of course), try not to let it get to more the 80C at extended full load

 

[philbar71]

do like bong said. up the core 5mhz at a time, test with ati tool. 80c seems a little too high. when i got my card up to 860mhz core it craps out at about 65c does not like to go any higher than 65c, even on stock clocks. so be careful, 850mhz on a 4870 seems too high without a volt mod.

 

[BongWizard]

i've seen my cards run up to 83C after about 3 days of straight folding, so temps around there dont bother me too much these days

 

[philbar71]

i'm pretty paranoid about temps on my hardware, so all of my fans are hard wired to a fan controller, even the video card fan. it's nice when i want to change the fan speed in game. my card starts getting artifacts at about 65c, no matter what the clock speed.

 

[gdon12]

leave the memory alone for now and increase the core freq by 5-10MHz each time, testing for artifacts each time (ATITool is good, or you can just run the SM2 and 3 tests in 3dmark06)... when you do start to get artifacts, back the core down about 5MHz... this is gonna be your top core speed with stock voltage.

When u say increase it by 5-10 mhz each time, do i increase it every 5 minutes or just increase it and test it? Btw whats stock cooling ? im guessing the fan that the GPU came with (sorry im quite new at this im trying to learn. My temps hasnt even gone close to your temps, havent seen this gpu pass 53C with its default.
1 more thing, when i try to test out for artifact what should i increase at 5mhz at a time, the Gpu clock or memmory clock? and Whats the difference between memory clock and gpu clock? i am mainly doing this for framerate, the game left 4 dead runs nice and smooth but the game spiderman web of shadows keeps like pausing/skipping (is this even an issue of my Gpu?).

 

[AP4LIFETN]

your memory clock is most likely unstable...GDDR5 is quadruple the memory speed, so 900mhz = 3600mhz effective speed...1200mhz = 4800mhz effective speed...thats a REALLY BIG OC on memory

 

[Chad711]

the most you will probably get out of that is 840/1100

 

[BongWizard]

When u say increase it by 5-10 mhz each time, do i increase it every 5 minutes or just increase it and test it? Btw whats stock cooling ? im guessing the fan that the GPU came with (sorry im quite new at this im trying to learn. My temps hasnt even gone close to your temps, havent seen this gpu pass 53C with its default.
1 more thing, when i try to test out for artifact what should i increase at 5mhz at a time, the Gpu clock or memmory clock? and Whats the difference between memory clock and gpu clock? i am mainly doing this for framerate, the game left 4 dead runs nice and smooth but the game spiderman web of shadows keeps like pausing/skipping (is this even an issue of my Gpu?).

you're right, stock cooling is simply the heatsink that comes with the card

increase the clock, then do an artifact test... this way you'll know where you start getting unstable

you wanna increase the GPU clock first... this is the cycling frequency of the GPU core... after you've hit your max core clock, you can go on to increase the memory frequency (which refers to the speed at which the memory bus is addressed)

oh yeah, the issues you've got with Spiderman is not a GPU problem... its more than likely a driver level issue. have you got Hydrid CFX enabled? are you sure your 4870 is set as the primary graphics adapter?