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Overclocking Late 2012 iMac GTX680MX

Fried Chicken

Fried Chicken

Suspended
Original poster
Jun 11, 2011
582
610
I'm using MSI afterburner to overclock the GTX680MX.
This is netting me 60fps Ultra on BF3 with Anti-Aliasing off.

I'm pushing the Core Clock to 920 Mhz (+230) and the Memory Clock to 3000 Mhz (+503).

This is causing my GPU to run in the high 70's low 80's and I think it hit 91 C at some point.


I heard the maximum operating temperature is 98C for the GPU.

What are the risks with overclocking? I've never overclocked anything before.
 
Fried Chicken said:
What are the risks with overclocking? I've never overclocked anything before.
Click to expand...

Er, a broken computer?

Seriously you should take care and a close eye on the temperatures and personally I would not push the overclock that far, especially on the core overclock.
 
Chippy99 said:
Er, a broken computer?

Seriously you should take care and a close eye on the temperatures and personally I would not push the overclock that far, especially on the core overclock.
Click to expand...

Since the GPU automatically clocks back at 98C, is there still an inherent risk to the GPU?
 
Fried Chicken said:
Since the GPU automatically clocks back at 98C, is there still an inherent risk to the GPU?
Click to expand...

Yes. You are stressing the components more than was allowed for in the Apple design and with an All in One where space is at a premium and heat control difficult, there probably isn't a lot of headroom to play with. In particular the GPU will draw more current than catered for in the design. You could break the PSU, GPU, motherboard and possibly more. If you don't go mad, then the risks are moderate, but there is still a chance your beloved Mac might crash and never reboot.
 
I´ve wirtten this a bunch of times, but I'll mention it a last time... Don't overdo the memory overclock. It doesn't help the framerate in a noticable way. My favourite overclock is 250/375, or maybe 230/350 if your card has a lower tolerance. The gpu ram overclock setting obviously has more leeway than the GPU overclock.Any higher than those settings doesn't make any sense, as the framerate difference will be very small, and you'll only get unecessary heat. Also, set the fan at a higher static speed to avoid those temperature buildups (max 2500rpm, but less for older, less demanding games), and also disable cpu turbo boost.

And, yes overclocking can be fairly safe if you know what you're doing. Don't start overclocking blindly, always do research first.
 
Mac32 said:
I´ve wirtten this a bunch of times, but I'll mention it a last time... Don't overdo the memory overclock. It doesn't help the framerate in a noticable way. My favourite overclock is 250/375, or maybe 230/350 if your card has a lower tolerance. The gpu ram overclock setting obviously has more leeway than the GPU overclock.Any higher than those settings doesn't make any sense, as the framerate difference will be very small, and you'll only get unecessary heat. Also, set the fan at a higher static speed to avoid those temperature buildups (max 2500rpm, but less for older, less demanding games), and also disable cpu turbo boost.

And, yes overclocking can be fairly safe if you know what you're doing. Don't start overclocking blindly, always do research first.
Click to expand...


So where can I learn?
 
Fried Chicken said:
Thanks for this.

I've followed the instructions and I have the desired results.
I wish the apple windows fan drivers would keep the CPU/GPU cooler, I don't like having a fixed fan speed using Lubbo's Fan Control.
Click to expand...

For fan control, try Macs Fan Control instead. Much better than Lubbo's. :)
http://www.crystalidea.com/macs-fan-control

If you have a fusion/hard drive, make sure the hard drive doesn't get hotter than high 50s celsius. When the hard drive reaches 60C, that's not good in the long run. Another reason why SSD is great. The SSD in my iMac w/680MX goes up to typically 40C when gaming, the highest I've seen is 42-43C celsius after playing something like Crysis 3 for several hours with overclocked GPU.
For temp monitoring HWiNFo32/64: http://www.hwinfo.com/download.php
 
If you are not increasing the voltage, the risks are very low. Yes, your card might overheat, in which case you will experience graphics artefacts and/or crashes - just lower your overclock and try again. It is advisable to run a burn test (some sort of very GPU-intensive application) for prolonged periods of time when testing the over clock for stability - watch your temperatures and abort/lower the clocks if you do not feel comfortable with the heat. You can use the temperatures reached during the burn test while at the default clocks as reference. Generally, high overcooks are not advisable due to the iMac's thin profile and therefore limited thermal envelope. Make sure that the temperature reaches a plateau quickly and does not climb - the later is a sign of inadequate cooling.

P.S. If you actually increase the voltages, you might well fry your card. I do not recommend a novice to do this.
 
is 90c ok?

hey im running late 2012 27 IMAC fully speced and i started to over clock my 680mx last night while playing bf4. i used presision x. my temp goes up to 90c and stays there. is that bad? i cant find anywhere that tells me what the max temp for the 680mx is so if anyone knows please let me know.

i am running 200/250.

thanks
 
I have my overclock set to 324 on core and 500 memory. Seems crazy, I know I never use it. Max temp is 95c. This only problem I have is when the memory is set to 504, then it crashes. Under load it sounds like an airplane, because the fans are oc'd 30%. I'd say this is the best Machine
to overclock from Apple. (My normal everyday overlclock for arma, bf, civ, etc. is 500 mem and 250 core.
 
Last edited:
The sign of a good game is if it plays well no matter how fugly it looks.

Drop the res down a bit and enjoy it, safe in the knowledge that your hardware (which you spent a lot of money on) will last many more years, long after that £40 game you bought got boring.

Some of us here can only dream of buying a high spec iMac and if I could I'd be doing everything in my power to make sure it lasts.

I'm not trolling, I'm simply asking is it worth it? If money isn't an object or important, buy a dedicated gaming rig or a PS4 or something.
 
Twimfy said:
The sign of a good game is if it plays well no matter how fugly it looks.

Drop the res down a bit and enjoy it, safe in the knowledge that your hardware (which you spent a lot of money on) will last many more years, long after that £40 game you bought got boring.

Some of us here can only dream of buying a high spec iMac and if I could I'd be doing everything in my power to make sure it lasts.

I'm not trolling, I'm simply asking is it worth it? If money isn't an object or important, buy a dedicated gaming rig or a PS4 or something.
Click to expand...

Why would you then buy a beautiful looking, expensive computer for gaming, and then run games in non-native resolutions (which looks like crap compared to native). This doesn't make any sense. If you have only so much money, get a proper gaming PC, and if you also need a laptop for school work buy a MacBook Air or something.
 
Mac32 said:
Why would you then buy a beautiful looking, expensive computer for gaming, and then run games in non-native resolutions (which looks like crap compared to native). This doesn't make any sense. If you have only so much money, get a proper gaming PC, and if you also need a laptop for school work buy a MacBook Air or something.
Click to expand...

I'm not sure if you're agreeing with me or disagreeing?

All I was saying is that if you've bought an expensive iMac, you surely can't have done it specifically for gaming, nobody realistically does that UNLESS they're expecting to take a slight performance hit in some circumstances.
 
Twimfy said:
I'm not sure if you're agreeing with me or disagreeing?

All I was saying is that if you've bought an expensive iMac, you surely can't have done it specifically for gaming, nobody realistically does that UNLESS they're expecting to take a slight performance hit in some circumstances.
Click to expand...

thats pretty much what i was doing.
look i wanted a imac for audio work, so i got one. i love playing games, so i play them on my expencive high spec imac.i just wanted to know if i could make it even beter. I know anyone could go buy a gaming pc for much less but i spent my money on this, so i want to make it the best i can, feel me?

peace:)
 
Twimfy said:
I'm not sure if you're agreeing with me or disagreeing?

All I was saying is that if you've bought an expensive iMac, you surely can't have done it specifically for gaming, nobody realistically does that UNLESS they're expecting to take a slight performance hit in some circumstances.
Click to expand...

I did it.

I got the top spec iMac for gaming and it did cost more.
But, otherwise I would have had to lug around 2 computers, one gaming machine and one mac.
Plus I also get the advantage of having gaming machine power on the mac side.
Not to mention my gaming machine is built with the quality of the apple hardware that will last for 5+ years.

And it's playing current games on ultra at 1440p at 60fps.
And if I needed an upgrade, I could sell this one and get a new one with
the latest and greatest graphics specs.
 
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