6750m extreme overclocking guide

By default 6750M runs 600/800 (core/mem) at 1.00V, however these clocks run fine at 0.855V. This means it is possible to overclock using lower than stock voltage which will enable faster performance and lower operating temperatures (e.g. 750/950 at 0.955V). A win/win situation. You can always choose to overvolt (>1V) for a higher overclock (above 800 core). I'm not responsible for any damage to your hardware as a result of this guide, exercise caution and keep an eye on your GPU's temperature.


FINAL UPDATE : ~800/900 @ 0.955V is the best all-round overclock. Performance gains through overvolting and going above 800 core and 900 mem are minimal and not recommended.


Tools needed:
ATI Tray Tools (ATT) - http://forums.guru3d.com/showthread.php?t=320467
GPU-Z (optional, for double checking) - http://www.techpowerup.com/downloads/SysInfo/GPU-Z/



Right click on ATT in the taskbar and go into Overclocking.


Ticking "Include clocks in profile" allows you to save the current clocks as a profile for easy access or for automated overclocking under "Game Profiles".

If going higher than 1V, ensure MBP is plugged into magsafe adapter and windows power options profile is set to performance.
Press on "Set Default Clocks" to reset card to original state. Only Overclock when needed and never overvolt on battery power.

edit 25/4/11 - Max recommended is ~870 core (give or take 10MHz)/1050 mem @ 1.05v

edit 27/4/11 - Overclocked 750/950 @ 0.955V running at lower temps than stock 600/800 @ 1V


edit 28/4/11 - Cleaned up guide, added osd,hotkey,game profile usage





Game Benchmarks

Crysis 2



Bulletstorm, 600/900 vs 880/990 on 1680x1048, High Settings, Med Post Proc





Go ahead, experiment and post your results + benchmarks !

 

Played Bulletstorm for 20minutes on 880/990 with no crashes, I'll do some 3dmark tests later on. 80-90 temps in GPU-Z under load.


edit- Card info reported by ATT, interestingly the MAX VDDC is rated at 1.260v doubt its accurate as card goes wildly unstable above 1.1v.

Display adapter ATI display adapter (0x6741)
Core Name NI WHISTLER
Driver Version 11.2
Release Version 8.812-110104a-112011C-Apple

Level 0 : GPU/MEM/VDDC 100.00/150.00/0.900
Level 1 : GPU/MEM/VDDC 400.00/793.75/1.000
Level 2 : GPU/MEM/VDDC 600.00/793.75/1.000

Core clocks Min 50.00 - Max 600.00
Memory clocks Min 75.00 - Max 793.75
VDDC Min 0.410v - Max 1.260v

Video BIOS Information
Version 013.011.000.010
Part Number 113-C0170K-04G
Date 2011/01/19 18:58
Vram Type GDDR5

 

Breaking 10k in 3dmark 06 (850/1050 @ 1.050V), these clocks are stable, temps ~80, for some reason I only get ~8600 w/o oc'ing while the norm reported is ~9500, must have a bad chip or 2.3 cpu makes a 1k score difference

 

Just trying to find the limits of the card But a few extra fps in graphics intensive games does make quite a difference.

 

You definitely have a better chip, best I can do is 800/1000, 820 runs ok in some games on 1v but crysis 2 doesn't seem to like it. Memory max freq is ~1100, Not sure about core tried up to 880 on 1.05v, 900 sounds a little too far.

 

Try 800/1000 (core/mem)

850/1050 @ 1.04v . Average 79 deg, would be lower if custom fan control worked.

 

You may need to re-apply thermal paste, a few threads about that. Increasing volt does affect heat, at 1.1v card would overheat and shutdown so I suggest 1.05v and under. 850/1050 @ 1.04v seems to be working well so far.

 

After much testing, 870/1000 @ 1.035v seems to be the best stable clock I could achieve, it may be different for everyone. These cards seem to have a core limit of 880, 900 would crash no matter how many volts given.

@Rotsu, I dont know what to make of that, did you check fan speeds?