Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
I continue to be impressed by this card:

Tomb Raider

IMG_%20%2076.jpg

IMG_%20%2077.jpg

IMG_%20%2078.jpg
 
I think I can achieve 9000+ once the official driver is out. Every time I try to overclock beyond normal threshold, it restarts my iMac. So far it's 28% faster than 680M by any means, it might be possible to push up to 9700.
I managed to achieve 1170mhz (100% stable) with my Retina Macbook Pro (650m), using the same method.

now the driver official driver is out and supports the 680mx. do you overlock beyond? or is 290/500 the highest possible?
 
hi When I am playing Crysis 3 (The only game I have at the moment) Love it :)
I have a Temp around 84c-86c on GTX 680MX

When I have it overclock to 200/250 I have the same temps.. start to wondering, is that possible? little scarred about the high temps.

When I have it overclock (MSI Afterburner) I have also the fans via lubbos set to minimum fan speed 1200rpm and max to 2100rpm, Have also tried to sett it to 2500 but it sounds to mutch I think hehe..and is it Normal that lubbos direct go upp to my max settings (2100) when I click apply?


My i5 CPU is around 80c-85c MAX is thats normal? I have also Disable the turbo like Mac32s advice (no different on my iMac)

I have play Crysis 3, 3-4 hours everyday and it works great overclock! no problem at all, no rebooting. just worry about the temps..


sorry for my English :) and all the questions..:)
 
hi When I am playing Crysis 3 (The only game I have at the moment) Love it :)
I have a Temp around 84c-86c on GTX 680MX

When I have it overclock to 200/250 I have the same temps.. start to wondering, is that possible? little scarred about the high temps.

When I have it overclock (MSI Afterburner) I have also the fans via lubbos set to minimum fan speed 1200rpm and max to 2100rpm, Have also tried to sett it to 2500 but it sounds to mutch I think hehe..and is it Normal that lubbos direct go upp to my max settings (2100) when I click apply?


My i5 CPU is around 80c-85c MAX is thats normal? I have also Disable the turbo like Mac32s advice (no different on my iMac)

I have play Crysis 3, 3-4 hours everyday and it works great overclock! no problem at all, no rebooting. just worry about the temps..


sorry for my English :) and all the questions..:)

Hi bd,
I have the 3.4ghz i7 CPU (which is hotter during load than the i5), and my CPU temp is now at max 77-78C when playing Crysis 3 for several hours. GPU max at 81-82C. This is 680mx overclocked to +250/+375, no vsync. I set the fan speed at 2500rpm, and just use headphones. Then you don't notice the fan noise very much. :)
You turned off CPU turbo mode by setting max CPU speed to 99% (advanced power options in control panel), right?

Regarding your temperatures, others can probably give a more informed answer to that. However, I think you should turn up the fan to 2500rpm all the time when playing Crysis 3. In a closed system like the iMac very high CPU and GPU temperatures could affect other components. Do you have a regular hard drive or SSD? Make sure your hard drive is not hitting 60c, hard drives are extra susceptible to high temperatures. 80c is normal for a GPU at full load (Crysis 3), but personally I'm uncomfortable with going beyond 80c in an iMac.
 
Last edited:
Hi bd,
I have the 3.4ghz i7 CPU (which is hotter during load than the i5), and my CPU temp is now at max 76-77C when playing Crysis 3. GPU max at 79-80C. This is 680mx overclocked to +250/+375. I set the fan speed at 2500rpm, and just use headphones. Then you don't notice the fan noise very much. :)
You turned off CPU turbo mode by setting max CPU speed to 99% (advanced power options in control panel), right?
Playing older or less demanding games now (like Crysis 1, Alan Wake etc.) gives very manageble temps, the CPU temps are in the high 60s. :)

Regarding your temperatures, I'm not an expert in that area. However, I think you should turn up the fan to 2500rpm all the time when playing Crysis 3. In a closed system like the iMac very high CPU and GPU temperatures could affect other components. Do you have a regular hard drive or SSD? Make sure your hard drive is not hitting 60c, hard drives are extra susceptible to high temperatures. 80c is normal for a GPU at full load (Crysis 3), but personally I'm uncomfortable with going beyond 80c in an iMac.

Alan Wake is a very demanding game, even by today's standards. I have to turn down a ton of settings on my iMac to get the frame-rate up, especially in 1440p.
 
Alan Wake is a very demanding game, even by today's standards. I have to turn down a ton of settings on my iMac to get the frame-rate up, especially in 1440p.

Absolutely, but less demanding than Crysis 3. :p Weird, I have everything at max except for antialiasing, and get a framerate at 40 and higher pretty much all the time as far as I can remember. I also said less demanding, since my GPU and CPU temps here are lower compared to Crysis 3. I first tried Alan Wake with low settings on my 2009 MacBookPro, and I got like 1 fps...if that. lol :)
I was disappointed by Alan Wake, love the setting and the concept, but it quickly got boring (still in ep.2). This game would have been so much better with some added adventure game-like puzzles IMO.
 
Last edited:
anyone tried dota 2 on max reso and max settings + vsync on? what fps r u guys getting?
 
Thanks MAC32 for your time and answer :)

Yes I turned off CPU turbo mode by setting max CPU speed to 99%, how can it be possible that i have 80c-81c on CPU just i5? you think the disable CPU turbo have better effect on i7?

I have a 1TB Fusion drive. thanks will check the temp on the HDD.

Your GPU max at 79-80C how can that be? when I have 84c-86c when its not overclock? and when overclock to 200/250 its around same for me...is it the the fan speed? most try on 2500RPM time to pick up my old headphones :)
 
Thanks MAC32 for your time and answer :)

Yes I turned off CPU turbo mode by setting max CPU speed to 99%, how can it be possible that i have 80c-81c on CPU just i5? you think the disable CPU turbo have better effect on i7?

I have a 1TB Fusion drive. thanks will check the temp on the HDD.

Your GPU max at 79-80C how can that be? when I have 84c-86c when its not overclock? and when overclock to 200/250 its around same for me...is it the the fan speed? most try on 2500RPM time to pick up my old headphones :)

Hi there! Man, I'm spending way too much time playing computer games after I got my iMac. The 680mx kicks butt. :D
It's definately the fan speed. I did notice my GPU got up to 80-81 after playing Crysis3 for several hours, but that's at +200/+300 and +250/+375 (hardly any temp difference between those overclocks). Now playing STALKER with Complete addon at +285/+425 100% stable, nice game!

Just download Lubbos fan speed controller, then set your fans to 2500rpm and enjoy. :)
Pretty nice that disabling CPU turbo boost also gives a higher stable GPU overclock, at least for the i7 CPU.
 
Hi there! Man, I'm spending way too much time playing computer games after I got my iMac. The 680mx kicks butt. :D
It's definately the fan speed. I did notice my GPU got up to 80-81 after playing Crysis3 for several hours, but that's at +200/+300 and +250/+375 (hardly any temp difference between those overclocks). Now playing STALKER with Complete addon at +285/+425 100% stable, nice game!

Just download Lubbos fan speed controller, then set your fans to 2500rpm and enjoy. :)
Pretty nice that disabling CPU turbo boost also gives a higher stable GPU overclock, at least for the i7 CPU.

Be careful with those overclocks. You can hear the capacitors straining (coil whine) if you put your ear to the back of the iMac with those kinds of clocks. I don't know if the coil whine is bad in the long term, but it's definitely there. Tough to hear over the sound of the fans, but before they ramp up - you can hear it.
 
Btw. Try out HWiNFO64 for monitoring functions. It doesn't report all temperatures correctly, but the most important ones work (HD/SSD, ram, GPU, CPU etc.). It also has a nice tweakable OSD funtion, so you can see fps/GPU temp etc. in game.
 
Be careful with those overclocks. You can hear the capacitors straining (coil whine) if you put your ear to the back of the iMac with those kinds of clocks. I don't know if the coil whine is bad in the long term, but it's definitely there. Tough to hear over the sound of the fans, but before they ramp up - you can hear it.

Hm, could you describe this coil whine? I'm not hearing any difference in sound from my iMac gaming/overclocking or not. I turned down the fan speed, and even tried a couple of different games and overclocking settings.
 
Last edited:
Hm, could you describe this coil whine? I'm not hearing any difference in sound from my iMac gaming/overclocking or not. I turned down the fan speed, and even tried a couple of different games and overclocking settings.

It's a buzzing from the center of the iMac (it's the GPU). Stick your head round the back/center and you'll hear it, though with more difficulty when the fans spin up. It's really easy to hear it in games like Far Cry 3, Crisis 3, Alan Wake etc (games that really tax the GPU). With the overclock it's much, much easier, since it's pretty much inaudible without an overclock unless you shove your head behind your iMac.

If you alt-tab out of one of those games etc, the buzzing instantly stops. I can't hear the noise unless I listen behind the iMac with the GPU overclocked. It's VERY faint without the overclock.

Now, my first 2012 i7/680 iMac was a tad "faulty" in that I could hear the buzzing from 6 feet away without any overclock. My replacement now is much, much quieter, though an overclock of the GPU presents the capacitor buzzing pretty obviously if I listen for it before the fans ramp up. And like I said, if I put my head around the back, it's a very obvious buzzing (to me at least - I know people have variable tolerances to this sort of thing).

It sounds like this:

http://www.youtube.com/watch?v=tDRDAXkH35Y

Ignore the fan noise in that video. The electrical sound is very similar to what it sounds like. Apparently this coil whine is normal in high-end GPUs, but that doesn't mean I like it.
 
Last edited:
@Mac32 yeh same her, have gaming more this week then all last year :)
what is the temp for you in Crysis 3 with no overclock, normal fan speed and no disable turbo bost?


@WilliamG are you sure its not a cable or something touching the fan? I had it to and I have heard more people have it... someone was saying try to tilt the iMac to the side and it will go away... It work for me.. :)
 
Yeah, WilliamG, sounds like a cable slightly hitting the fan blade. Doesn't coil whine sound more like a high pitched even tone? Anyhow, not hearing anything different soundwise overclocking or not. Think I'm gonna continue to overclock the 680mx, it makes a big difference in framerate.
Going from only using laptops for 6 years, to gaming on a beautiful 27'' screen is pretty awesome. :D

Bulldog, I strongly advise against gaming with normal fan speed. Just accept some fan noise, and use a headset. Your roommates/neighbours will thank you also. ;)
 
Agree Mac32 putt the fan speed upp when gaming is a must... and I will..still curios what temp you get in Crysis 3 with no overclock, normal fan speed and no disable turbo bost :cool:
 
@Mac32 yeh same her, have gaming more this week then all last year :)
what is the temp for you in Crysis 3 with no overclock, normal fan speed and no disable turbo bost?


@WilliamG are you sure its not a cable or something touching the fan? I had it to and I have heard more people have it... someone was saying try to tilt the iMac to the side and it will go away... It work for me.. :)

Yeah, WilliamG, sounds like a cable slightly hitting the fan blade. Doesn't coil whine sound more like a high pitched even tone? Anyhow, not hearing anything different soundwise overclocking or not. Think I'm gonna continue to overclock the 680mx, it makes a big difference in framerate.
Going from only using laptops for 6 years, to gaming on a beautiful 27'' screen is pretty awesome. :D

Bulldog, I strongly advise against gaming with normal fan speed. Just accept some fan noise, and use a headset. Your roommates/neighbours will thank you also. ;)

It's not a cable. Like I said, it goes away as soon as you alt-tab out of the game (fan still running full pelt), and the GPU is not under load. I've no issues with the fan inside my iMac. If you don't hear the noise (especially when overclocking), that's lucky for you, I guess. :)

My Crisis 3 temps were in the high 70s to mid-80s. Nothing unusual.
 
ahh if its go away when alt-tab then its not the clicking from the cable...

so mid-80c is full normal on the new imac then? :D

What have you the rpm on in lubbos when gaming?
 
ahh if its go away when alt-tab then its not the clicking from the cable...

so mid-80c is full normal on the new imac then? :D

What have you the rpm on in lubbos when gaming?

For the GPU, yes. Anything under 90C is good enough for me. Not really reasonable to expect much less when slamming the GPU.

I don't use Lubbos. Not seen a reason to...
 
Well, playing older games like STALKER, you can set the fan at a much lower speed like 1700-1800, and still have moderate temperatures while gaming/overclocking. For Crysis 3 I would definately crank up the fan speed. :)

Btw. sorry for going of topic, but I'm trying to get STALKER: Clear Sky to work. Everytime I enable dx10 mode in the game, it crashes very quickly and I get a black screen. If anyone know a solution to this problem I would be very grateful..
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.