Boot Camp, the iMac, and system quietness

September 11, 2006 11:41 AM

Gaming on the iMac -- how does the ATI Radeon X1600 (and its fan) handle the 3D graphics load?

Last time, I asked about gaming on the iMac via Boot Camp, and you gentle souls assured me that yes, Half Life 2 runs with few hiccups.

I've seen this machine in person, and it's way quiet. Not Mac Mini quiet, maybe, but quiet. Which gets me to wondering: with the middle of the road ATI Radeon X1600 in the machine, how does Apple keep the iMac up to its standards of quietness?

Most ATI and Nvidia cards I've seen sound like F-15s gassing up in a windtunnel. Is the Radeon X1600 specially modified for the iMac to reduce the volume of the fans? Or is this an especially quiet card?

Whisper-quiet hardware headhunted me from Linux to the Mac Mini in the first place. I'd like to continue this experience with the iMac. Any thoughts on the GPU volume of this machine -- or anything related to gaming under Boot Camp -- would be greatly appreciated!

posted by Gordion Knott to Computers & Internet (5 answers total)

If it's anything like the MacBook pro, the fan can speed up as things heat up. It's a stock X1600. If you're in Windows-land, there are tools out there to over/under clock the CPU and GPU.
posted by rbs at 11:49 AM on September 11, 2006

I've been playing WoW and Half-Life 2, and the computer has yet to get loud. I've played WoW for long stretches of time without the fan turning on. Half-Life I bought recently, and I imagine it taxes the video card much more than WoW, but so far I haven't noticed the fan firing up loudly with that game either. The iMac is awesome.
posted by chunking express at 12:08 PM on September 11, 2006

They use a low-power laptop version of the chip, and they underclock it (300MHz when it's designed for 475MHz, I think). Also, yes, the fans come on automatically when you start running intensive programs, so it will get slightly louder.
posted by cillit bang at 12:15 PM on September 11, 2006

The same way they do it in most Macs. Big heatsinks, thermal friendly cases, and large fans. You could make a quiet-ish PC gaming rig if you wanted to.
posted by damn dirty ape at 12:20 PM on September 11, 2006

cillit bang got it. the iMac uses the Mobility Radeon X1600, the same GPU used in laptops and on top of that, they underclock it. Depending on which iMac you have, the default setting is around 300-400MHz for the core and the same range for the memory. People have reported that ATITool says it could go up to 540MHz core/597MHz memory, obviously with a lot more noise and heat.

Here's a discussion thread.
posted by junesix at 3:24 PM on September 11, 2006