6750m extreme overclocking guide

[Necriss]

Using battery power I get the high temps you're reporting. Plugging into magsafe gives me 79-85 overclocked.

Your fan speeds might be set to passive, to fix this go into Windows 7 power management, control panel --> power options --> additional profiles --> profile (high performance).

 

[Necriss]

oops double post

 

[noogin]

Any difference between ATI Tray Tools and MSI Afterburner?

 

[Inara]

I find it hard to believe that you only get 79 degrees using 850/1050

been using 750/900 for past couple weeks and pleased with results, highest temps get are 90 degrees with fans on max and 82-84 average

I have mine overclocked at 700 900 and i can see a peak temp of 89, with the fan working at 95% sometimes . I think it is not safe to go ahead in this way, if our fan loses efficiency because of the dust, for example, we ll have a fried gpu in my opinion

 

[Necriss]

Another interesting discovery, stock clocks (600/800) can be undervolted from 1.000V to 0.855V, runs perfectly (benched with crysis 2), 0.850 blacks out. This explains why the card can be overclocked to ~800/1000 without adding volts, its already running more than enough.

You can also undervolt and maintain a stable overclock, 750/950 running nicely on 0.955V.
Here are my current ATT profiles, feel free to use them as a reference.

As for the power benefits of undervolting it'll be nice if someone else can test that for us

 

[adrian1480]

very cool finding on the undervolting.

looks like I'm going to have to throw my 17" hat into the ring. curse you, Necriss!

 

[cdrgold]

I have a problem. Whenever i try to overclock, and i click apply, the screen goes black and nothing happens. I then have to hold down the power button to reboot. I'm not sure what is causing this

 

[aznguyen316]

Good stuff here. Stock volts I was fine around 820/950. I'll probably lower it to 800/950 or so and call it good for Crysis 2.

Anyway what are you guys using to check temps? GPU-Z doesn't read my temps.. says max is at 43C which I know isn't right after playing Crysis 2.

HWMonitor and realtemp read CPU temps but GPU is like sky high in the thousands lol.

 

[cdrgold]

I have a problem. Whenever i try to overclock, and i click apply, the screen goes black and nothing happens. I then have to hold down the power button to reboot. I'm not sure what is causing this

Turns out i didn't change the voltage. Tried running at 880 and 990, screen ended up freezing and flashing to a black screen

 

[henrikrox]

Would anyone mind posting a vid comparing the fps pre overclock and then after. Deciding if i Want to install bootcamp again.

Wouls be awesome.

At maybe 800/950 or somthing

 

[Arondel]

Another interesting discovery, stock clocks (600/800) can be undervolted from 1.000V to 0.855V, runs perfectly (benched with crysis 2), 0.850 blacks out. This explains why the card can be overclocked to ~800/1000 without adding volts, its already running more than enough.

You can also undervolt and maintain a stable overclock, 750/950 running nicely on 0.955V.
Here are my current ATT profiles, feel free to use them as a reference.
Image

As for the power benefits of undervolting it'll be nice if someone else can test that for us

It would also be nice to see the temperature difference on idle and load.

 

[ninja2000]

I will do some undervolt testing tomorrow, will be great for sofa gaming (i always underclock to play on sofa and overclock for desk gaming).
I have a kilowatt meter so will also work out load power.

Also guys, if you are having problems with fan profiles in bootcamp just use macfan and set a desktop icon for gaming fanspeeds (i use 4200rpm). Macfan will stay at this constant desired fanspeed unless temps get too high and it will then increase

 

[Necriss]

Turns out i didn't change the voltage. Tried running at 880 and 990, screen ended up freezing and flashing to a black screen

Freezing or screen going back is either unstable clocks or insufficient voltage. 880 is a bit on the extreme end some may be able to manage it at 1.05-1.06v, try toning it down to 850 with 1.03-4v.

I will do some undervolt testing tomorrow

Awesome hope the results are good.

 

[TXBDan]

How do you deal with switching between the integrated and discrete graphics cards? Do the profiles switch automatically when the graphics card does?

 

[Necriss]

How do you deal with switching between the integrated and discrete graphics cards? Do the profiles switch automatically when the graphics card does?

Intel HD 3000 is disabled under boot camp? For automatic profile switching use Game Profiles or create a hotkey to restore default clocks in ATT.

 

[TXBDan]

oh i see. how come my GPU core is 100mhz and mem at 150mhz? does it scale as needed or something?

 

[Necriss]

oh i see. how come my GPU core is 100mhz and mem at 150mhz? does it scale as needed or something?

yup, card automatically underclocks into 2D mode(100/150) when unneeded.

Anyway what are you guys using to check temps? GPU-Z doesn't read my temps.. says max is at 43C

GPU-Z should read temps fine, try using ATT's monitoring graph or flashOSD, source is named "GPU t". If its still inaccurate its probably a hardware fault.

 

[Inara]

I will try an underclock of 0.955 V plus a 750/950, if a manage to keep the max temp to 85 C (as peak) and the fan will not work up his 90%, I will be very happy (I want to have a safe room both on the fan capability and on the GPU).

I will keep you posted

Edit: 600-800 @0,955 V allows me to run 3dmark 2006 cooler of 2-3 C , I need some time to do extensive tests with Team Fortress 2 and Borderlands

 

[Icy1007]

For anyone who is not retarded: DO NOT DO THIS!!!

 

[adrian1480]

For anyone who is not retarded: DO NOT DO THIS!!!

come again?

 

[Icy1007]

come again?

Overclocking a laptop is just asking for trouble.

 

[Necriss]

Overclocking a laptop is just asking for trouble.

Not in this case
I can confirm that undervolt with overclock runs faster and cooler than stock settings muhahahaha

 

[tezro]

Looking very nice, especially the underclocking+lower temps.
However, this is a Windows only thing so how are we getting this in Mac OS X too?
Probably would require a EFI modification if possible, or does the ATI tools save it to the EFI directly instead of using a profile?

 

[ninja2000]

undervolting update

Right guys, I have spent the morning undervolting and testing!
I capped the cpu at 2.1ghz so the temps didn't affect my gpu temps. I also set the fans at 4200rpm (my gaming fan speed).

I am furmark stable with the following speeds:

450/600 @ 0.8v = 45watts
550/700 @ 0.85v = 48watts
750/800 @ 0.95v = 57watts and max temps 61c
I can overclock the ram but it didnt give me any extra fps over 800. Also I can probably push each step more but just wanted to get some rough figures.

I did a quick dow2 benchmark to see if the game was still playable at the lower clocks with my current setting - 1920x1200 all high but no AA

450/600 = 29-62-8.3 ave/max/min fps so still playable. at my normal 750 overclock I get 44-98-15 fps

 

[Mackan]

Looking very nice, especially the underclocking+lower temps.
However, this is a Windows only thing so how are we getting this in Mac OS X too?
Probably would require a EFI modification if possible, or does the ATI tools save it to the EFI directly instead of using a profile?

There exists no such overclocking tools for OS X. It's a real pity. I don't think there is any technical limitation here, it's just that there aren't enough people interested in writing such tools for OS X.