I was wondering how good thunderbolt is for adding a beefier PCI graphics card to my MacBook Air.
If I use a PCI enclosure like this, will the card integrate with the Mac to enhance the performance of the computer or a display?
Unfortunately, there isn't currently a graphics card on the market that has a Thunderbolt-aware driver. Without that, the solution isn't going to work. All of the manufacturers of such enclosures have stated that there is significant demand for exactly what you're inquiring about here, and you might be best served to join some of their mailing lists to keep up with changes, i.e. cards that become compatible. Magma for instance, has a list of "coming soon" cards on their site for their particular enclosure, but not a single graphics card. Yet.
Don't also forget - Thunderbolt in its current state has a theoretical maximum bandwidth of 10Gbps (that's gigabits), or 1.25 gigabytes, per second and is made up of a DisplayPort signal coupled with PCIe 2.0 x4.
As you may be aware, most high end graphics cards on the market are PCI 2.0 (or even 3.0 now) and run best with an x8 slot or ideally, x16. That kind of bandwidth — from 4GB/s on PCIe 2.0 x8 to 16GB/s on PCIe 3.0 x16 — is way over the ability of Thunderbolt.
So, even if there is eventually a card that would work, with a Thunderbolt-enabled driver that was available for your Mac - you won't likely get much more performance out of it that you couldn't get out of, say, the GeForce 650M chip in the current 15-inch Retina MacBook Pro (mid-2012).
For practicality's sake, I'd suggest thinking about how if your current laptop's graphics capabilities don't suit your needs, perhaps you might consider upgrading. It will be likely be a long time before there's a card that will run in the configuration you are contemplating.
I have read nothing but high marks for this sort of PCI expansion when you want to get any PCI card to work with a Mac.
As long as the card itself would work when it's in a Mac Pro, there's no reason to think an Air wouldn't recognize it. Any program that can offload calculations to the GPU would see a speed boost, but unless you ran an external monitor - the built in display of your Air would still be driven by the on-board GPU and not the external GPU.
The idea is a solid one on the way. First off you DON'T NEED an external monitor unless it is on the Mac operating system. This isn't much a problem as macs can EASILY do boot camp. You can use Nvidia Optimus software or LucidLogix GPU virtuMVP software to just offload the rendering of the integrated GPU onto any other discrete GPU ergo the external card. The problem isn't the external enclosure or the virtuMVP software. I talked to lucidlogix and they stated it WILL work provided the driver installs correctly and they wont because PCI Express dont play nice with thunderbolt sadly. So screw the bandwidth because many others have tried it with PCIE x1 via expresscard or the x1 slot beneath the laptop (windows long time ago) & anyway thunderbolt 2 is comin out so that there is double but regardless, you WILL see performance in general. Now there are hacks to getting cards to work externally however, they were based off of the old methods. http://www.journaldulapin.com/2013/08/24/a-thunderbolt-gpu-on-a-mac-how-to/ Try if you want but those methods require expresscard. It's on its way, I can't try this out myself because I can't afford those external thunderbolt chassys at the moment & they dont sell em in circuits like the old methods :(
They do have them, for PCIe cards.