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dtfgator

macrumors newbie
Original poster
Oct 28, 2009
6
0
A few months ago I purchased a new 21.5" iMac, with the i3 @ 3.2ghz and the 5670 GPU. However, I as get more competitive in Starcraft 2, I want a graphics card that can handle the game better, while still keeping my sexy iMac and its design capabilities (I'm a graphic designer, so Mac is pretty much a requirement).

Essentially, I have been digging around, and discovered that the iMac uses a standard PCI-E 16x slot to connect the graphics card the the motherboard. This means that I could in theory install any graphics card that would fit inside the case. However, due to size restraints, very few cards would actually fit, and most of them are either expensive custom cards, or budget "Sub-Par" GPU's.

I was pondering the possibility of designing a PCI-E Male-to-Male Adapter with a ribbon cable, and then a PCI Female end after that, in order to run the cable outside of my case, and install / attach a high-end card outside.

And then we run into driver issues with Mac.. I figured that I could most likely use the Radeon HD 5770 card (1gb), because it is supported in the Mac Pro, so it should work here too..

However, we run into another issue. The iMac cards are Bus-Powered, meaning that they don't require additional PCI Power connectors from the PSU (Which is small and low-ish powered in the iMac), but the 5770 does require additional PCI Power Connectors.


So.. Whats the solution here? Go for a nicer 1gb 5670 card and connect it externally for a slight boost, figure out a way to rig up an "External PSU" to run the 5770, or simply keep it the way it is, and buy a Mac Pro next time around?


I'd love your input and suggestions, or, if you know any details about the wattage of the iMac PSU, and if it has any PCI Power connectors that go the the GPI, I would appreciate that greatly.

Thanks!
 
iMacs use mobile GPUs so you would have to get a mobile GPU for MXM slot. OWC sells ATI 5750 (aka 5850M) which is meant for 27" iMac but it is possible that it would work in 21.5". Nobody has tried so you would be the guinea pig. There are two sizes on MXM modules and it is likely that the GPU used in 21.5" iMacs uses MXM-A cards which are 35mm shorter than MXM-B cards.

However, like said above, you are better off with waiting for a new one and then upgrading. Or build a separate Windows gaming rig.
 
iMacs use mobile GPUs so you would have to get a mobile GPU for MXM slot. OWC sells ATI 5750 (aka 5850M) which is meant for 27" iMac but it is possible that it would work in 21.5". Nobody has tried so you would be the guinea pig. There are two sizes on MXM modules and it is likely that the GPU used in 21.5" iMacs uses MXM-A cards which are 35mm shorter than MXM-B cards.

However, like said above, you are better off with waiting for a new one and then upgrading. Or build a separate Windows gaming rig.

The heat pipe may have to be modded as well.
 
Have you been gaming under windows? A nice upgrade is to get windows7, install it in your computer (upgrade in fps already) and then overclock it some in windows7 (more gain in fps)

owc does sell mobility 5850 for 27 inch, but it'd be up to you to test it out to see if it works for 21.5 inch.
 
$400 for that!?!?!?!!!!

No thanks, I'd much rather build my dream rig (6990, anyone) than get that card for the same price.. Or just upgrade the iMac..

And of course I have it gaming under a somewhat *cough* legal version of Win 7 Ultimate. Also I was able to get the GPU up to 900 mhz no problem in CCC, when still using SMC fancontrol.
 
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