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Any way to run a MBP cooler?

therealseebs

therealseebs

macrumors 65816
Original poster
Apr 14, 2010
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Okay, long story short: It is desireable to run a video game on a MBP (current model). It runs. It runs smoothly and stuff. Problem is:

1. It runs fans at max speed all the time.
2. It runs pretty hot.

The game hasn't got a setting for throttling its frame rate. Is there anything reasonably sane we can do to make things run cooler? A way to tell the CPU to run at a lower clock rate (or the GPU) would be fine; we could be totally happy with half the frame rate and slower fans.
 
therealseebs said:
Okay, long story short: It is desireable to run a video game on a MBP (current model). It runs. It runs smoothly and stuff. Problem is:

1. It runs fans at max speed all the time.
2. It runs pretty hot.

The game hasn't got a setting for throttling its frame rate. Is there anything reasonably sane we can do to make things run cooler? A way to tell the CPU to run at a lower clock rate (or the GPU) would be fine; we could be totally happy with half the frame rate and slower fans.
Click to expand...

1. Normal, it needs to cool itself not to fry.
2. More power being used = more heat, that's simple thermodynamics.

No, you can't make it run any cooler, you're gaming on a laptop, what exactly do you expect?
 
Well, what I was hoping for was the equivalent of a setting that some of my other laptops (not macs) have had, where you can set the CPU to "always run at half speed". Then it runs a ton cooler. Yes, it's slower; slower's fine. So, say, a 1.6GHz CPU might have a setting for "never go above 800MHz". And yes, I know that more power used = more heat. My request is for a way to tell the machine not to use that much power, by slowing it down.

FWIW, I have a workaround which is basically to have a background shell script which stops the game and restarts it in 5ms intervals. Amazingly, this works quite nicely; fans go to maybe 2800rpm instead of 6k, machine stays cool, frame rate drops from 40ish to 20ish and game is still perfectly playable. I find this sort of offensive but hey, it works.
 
OP, I don't see why you're so annoyed by the fans and heat. You're playing a game that produces a lot of heat on a computer less than an inch thick. The heat has to go somewhere. Obviously, the computer is designed to tunnel it away from the silicon so that you don't blow your expensive processor. The place it ends up going is into the air (fans) and into the case (aluminum case = massive heatsink). If you're gonna game on a laptop this thin, made of this material, you should be expecting it.
 
You might want to give some specifics; what game and what computer are you using.

Most games let you set wait for V-sync or vertical sync. That basically means that you video card will only send out frames in sync with your monitor. Forcing it down to 120, 60 or 30 fps. Lots of games have a way to cap the frame rate in their console as well.
 
Some stupid replies here. Quite a few games actually come with a frame rate limiter, so you can lower power consumption (and heat & fan noise), if desired.

The game in question apparently has no frame rate limiter. I don't think there is a possibility in OSX to down clock the CPU manually. In windows (bootcamp) this might be possible. For older MBPs there is something called coolbook, but this doesn't work anymore.

Which game is this? Rift in Crossover? MBP and OSX version?
 
While the MBP definitely runs hotter and the fans kick in at a higher RPM when gaming, there's no reason from a hardware longevity standpoint to throttle the framerate. As has been stated already in this thread, the aluminum body acts as a giant heat sink, so instead of simply relying on the fans to dissipate the heat, the entire case is acting like an external radiator and venting heat directly to the outside. A lot of Mac users are coming over from windows and laptops with plastic and/or composite cases that don't transfer heat directly through the body, so people automatically assume something's wrong with the machine because of it. If you measure the fan exhaust for a 15" MBP and a Dell XPS M1530 or equivalent, you will see that the temperature of the air leaving the cases is virtually the same. The only real difference is that aluminum draws heat away from the core components, whereas other materials do not.

A lot of games default to running at the max framerate possible unless V-Sync is enabled in the game's video preferences. V-Sync will limit the framerate to what your monitor can support. It's usually the GPU that's generating the excess heat, so limiting the CPU speed will not make as big a difference as one might presume. My MBP runs cool and quiet when surfing the net, working with iWork/iLife/Aperture, but once the dedicated GPU kicks in, the heat and fan speeds ramp up accordingly.
 
There is actually the possibility of downclocking and undervolting the GPU until it is barely fast enough to cough up the menu in the game, and that should fix heat problems for most older games with simple graphics.
 
Are you playing on your lap and frying your balls? If that is a no, then put some headphones on and enjoy the game you're playing :)
 
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