Sign in with
Sign up | Sign in
Your question

External Graphics Card Question

Last response: in Graphics & Displays
Share
March 24, 2012 3:06:49 AM

Hey, sort of an odd question here. My curiosity on this matter doesn't necessarily stem from a desire to increase performance, but to push my hardware to it's limits. I'm wondering if it would be POSSIBLE (please don't reply saying that it'd be too expensive, go build a gaming rig, etc. I know this isn't really feasible; I just would like to know if it can be done.) to rig an external graphics card to an iMac through a PCI-e slot, namely the PCI-e mini slot that the Wireless Wifi card connects to. If that was to be removed, would it be possible to route an external graphics card module thru that slot and then run a secondary monitor to it, which could then utilize the new card and the processing power of the iMac for gaming? Again, this is simply theoretical, and I would like to know, if it can or cannot be done, the technical reasons why.


Tyrannus
a b U Graphics card
March 24, 2012 3:23:17 AM

I've never heard of such a thing existing, that is any sort of external solution for a GPU, connecting to a Mac no less, to improve performance.

m
0
l
Related resources
a b U Graphics card
March 24, 2012 3:55:19 AM

Yes, it is possible. You already seem to know about external GPU stuff, so I won't go into the details, but I've heard of people doing it. I'll see if I can find the guy.
m
0
l
a b U Graphics card
March 24, 2012 3:57:09 AM

^ News to me.
m
0
l
March 24, 2012 9:51:04 PM

Interesting kajabela. If you find any info please let me know. And as for the Thunderbolt solution, that would be perfect, except... the iMac in question doesn't have a Thunderbolt port. Which is why I'm interested in ghetto rigging it to a PCI slot somehow. And the only one I've even heard of anything removable being connected to so far was the PCI-e Mini slot that the Wifi card connects to... Hence my curiosity. Not sure that it can be done, in fact I'm sure there's a plethora of reasons why it can't. But it never hurts to ask knowledgeable people :) 

Tyrannus
m
0
l
a b U Graphics card
March 25, 2012 8:34:53 PM

Oh, sorry. I've heard of it being done on Windows laptops, but never an iMac. That would be a pretty intense case mod, to start with. Anything more I tell you will be off Google.
m
0
l
March 25, 2012 9:02:20 PM

I think your bottlenecks would be two things:

1. Getting your system to recognize and use the card, which would probably be difficult on a Mac (since they are build to run on pre-configured setups only).
2. The bandwidth (is this the right word?) of the PCI-E mini slot. A graphics card is going to use a lot of data, which is why they normally go in x16 slots. I'm guessing your mini slot simply can not carry as much data at one time, and so that may make it totally pointless to try.

The reason the Thunderbolt solution is the best is because Thunderbolt can carry an insane amount of data very quickly, which makes something like an external GPU solution feasible.
m
0
l
March 26, 2012 1:34:15 AM

Learned a couple things. Found a link: http://www.hwtools.net/adapter/pe4h.html which shows an adaptor that can convert PCI3 x16 (thru their addon card) to either expresscard (which the iMac doesn't have, obviously) or... drumroll... PCIE MINI! So I'll use this adaptor to attach their addon card to the slot where the Airport Extreme is in the iMac, after I remove it. Then I'll try to rig the graphics card to that addon card, with it's own independent power supply. So maybe when I have a few hundred extra bucks, and a week off work, I'll try n rig this thing up. I've not gotten my hopes up that it'll work, but I'll never know unless I give it a shot. And as for case-modding, the only modification I'd have to make to the iMac itself would be a small hole in the grid at the bottom of the case so I can run that adaptor cable thru it. The rest of everything I'm planning on using will be attached to that cable and will be able to sit nicely on my desk. If anyone has any suggestions, or anything useful, feel free to share :)  I can always use more advice. But this is just the rough draft of my plan.

OH a sidenote: The graphics card is obviously going to be run with Windows XP thru bootcamp, if I didn't already mention that, which I don't think I did.

Tyrannus

EDIT: Yes, I am aware that converting PCIe to PCIe Mini will reduce it to x1 instead of x16... trying to figure out how to get around that.
m
0
l
March 26, 2012 3:38:47 AM

Here's my question now.. If i was to do this, and I connected a very high powered card to the iMac via this setup, is the performance hit 'hard capped' so to speak (like, diminishing returns: at one point, no matter how you upgrade the card, the bus lane won't be wide enough to increase performance anymore, or it will become too miniscule to notice, even with fps monitors and such), or would performance increase as a percentage of the graphics card's base performance? Like if I added a card with X amount of processing power and Y amount of memory, would the performance of the rig Z increase like this: (And I'm using 50% decay of standard performance when the card is run thru the rig as an example)

(X + Y)(.5) = Z

Or would it be like..

When X + Y <= 1,
(X + Y)(.5) = Z
When 1 < X + Y < 2,
(X + Y)(.12) = Z
When 2 < X + Y < 3
(X + Y)(.01) = Z

If this doesn't make any sense to you, I'm sorry.. This is just the best way i can describe it.

Tyrannus
m
0
l
!