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6750m extreme overclocking guide

N

Necriss

macrumors member
Original poster
Apr 22, 2011
61
0
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.
oc1o.jpg


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
gpunderclock.jpg


edit 28/4/11 - Cleaned up guide, added osd,hotkey,game profile usage
oc3u.jpg

oc4h.jpg




Game Benchmarks

Crysis 2
crysis2benchmark.jpg



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

880core.jpg




Go ahead, experiment and post your results + benchmarks !
 
Last edited:
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
 
Last edited:
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 :(

3dmark06ah.jpg
 
wow man,great stuff,your a champion,ive been using msi but will give this a try,can you pls report back after more testing?say give it a couple of days to see how stable,have to be careful with overclocks say what?;),g1.
 
eeeeh...increasing the voltage worries me.

were you not getting enough speed with a simple OC? I'm getting similar numbers with just a basic OC. 750/950, I believe it is.

via Afterburner (instead of ATI Tray tools)
 
Cant wait to try this when back from holiday. Hopefully it will give me performance increases in Angry Birds :)

Thanks for the info!
 
adrian1480 said:
were you not getting enough speed with a simple OC? I'm getting similar numbers with just a basic OC. 750/950, I believe it is.
Click to expand...

Just trying to find the limits of the card :) But a few extra fps in graphics intensive games does make quite a difference.
 
Necriss said:
Just trying to find the limits of the card :) But a few extra fps in graphics intensive games does make quite a difference.
Click to expand...

I hear you, man. I just don't want you to fry your stuff. volt-modding a laptop GPU seems like a very dangerous decision. at least with our desktop cards, we can just replace the card, you know? I'll be keeping an eye on the thread and I hope the best for you.

Maybe I worry too much. idk.
 
adrian1480 said:
I hear you, man. I just don't want you to fry your stuff. volt-modding a laptop GPU seems like a very dangerous decision. at least with our desktop cards, we can just replace the card, you know? I'll be keeping an eye on the thread and I hope the best for you.

Maybe I worry too much. idk.
Click to expand...

Not that danger.

When I first got my Acer 5740G, I OC it up to 700Mhz right off with volt increase and use it as a gaming machine for year, not having a single issue with it.

The only thing that will danger it is the temperature....
As long as you can keep it down, I doubt you will have any issue with it.
 
How far can you overclock on the stock 1v voltage?

I am at 820/1000 stable. I am half tempted to see how much extra I can push it with 1.05v but to be fair, everything I have been playing runs great at 1980x1200.
 
ninja2000 said:
How far can you overclock on the stock 1v voltage?

I am at 820/1000 stable. I am half tempted to see how much extra I can push it with 1.05v but to be fair, everything I have been playing runs great at 1980x1200.
Click to expand...

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.
 
Thanks for the response!

I havent tried any higher than 1000 on the memory, I havent found any games that are memory bound even at 1200. I get almost no improvement from 800 to 1000.
The core makes a massive difference though. Shogun 2 goes from unplayable (20-30fps) to playable (30-40fps) at 1200p.
 
Necriss said:
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 :(

Image
Click to expand...

I had the same problem, I achieved 6500 at stock freq and 7400 with an oc 700/900, then I reinstalled win 7 with the same oc I achieve 10650, like you. For this reason I suggest a fresh installation before going on with an extreme oc, just my two cents.
 
To whoever is doing this. Can you take a really close look at the max load temperature of the GPU specially after a long period of gaming session and report it please? It's quite dangerous for the GPU to go into the 90s temps for long time. If 90c is the mac temp then i might try this as well.

To the OP, can you record the temps for heavy games like crysis 2 for example? Let's say after an hour of gameplay? Thanks :)
 
That is good temps for that kind of overclocking....Increasing voltage did not increase the heat? that's is surprising. My Machine hits 90c with 800/1000 without changing the voltage. That's weird.:confused:
 
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?
 
Thx for the help op. Great thread. Will try 800/1000 on stock clocks after easter. Thx for answer.

And also thanks for testing it out for us:)
 
Necriss said:
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
Click to expand...

It probably is accurate, just not easily reachable on every die, plus you have to take into account the notebook that the die is in as well. Not every notebook will be able to deliver that voltage (consistently at least). Cooling is the other issue.
 
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
 
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