What's a good graphics card for Yosemite on a Mac Pro 1,1? I'd like to upgrade my Mac Pro 1,1 (using the EFI workaround hack) to run Yosemite so all my Macs are running the same version of OS X.

This old box is only used as an HTPC, so smooth 1080P video playback and good UI response is all I need -- I don't game or do anything serious on it.

Can anyone recommend an inexpensive card? Or barring a specific card, anything I should avoid or look for in a card so it plays nice with Yosemite?

I'm currently running 10.7.5, so ideally I'd like a card that has no trouble with that version as well.

I'm leaning toward an XFX HD 6670 (link below), since I hear it works OOTB on these boxes with Lion, but I have no information about whether it works well with the final version of Yosemite.

http://www.amazon.com/XFX-650MHz-PCI-Express-Graphics-HD667XCLF3/dp/B00AHV7NNE/ref=cm_cd_ql_qh_dp_t
I ended up going with the aforementioned card (the "XFX HD 6670 650MHz 2GB DDR3/HDMI/DVI/VGA PCI-Express Graphics Card HD667XCLF3") and it worked brilliantly in both Lion and Yosemite.

I've only been using the DVI output, not HDMI, so I can't say anything for sure about the HDMI output.