Hi! Short version: I need a GPU which supports metal for my 5.1 flashed Mac Pro 2009. Would GTX 680/780 be possible? I'd like to flash to Mac EFI as well. My GT120 might not last much longer it seems, and I'd need it to be fully compatible. Long version: I got a 2009 Mac Pro for free a few years back which has been sitting in storage since, as I have a 2008 Pro with GTX 285 which has been serving me well. The 2009 Mac Pro only had 3GB of RAM and the cheapest Xeon CPU (quad 2.66) and no Wifi, but recently I discovered that it is identical with the 2010 board, and therefore tried the 5.1 flash; 10 minutes later I had a Mac Pro 2010, and 30 minutes after that again - High Sierra instead of El Capitan. So I'm ordering a X5690 (single GPU tray), and I've already upgraded to 16GB RAM, and I also want a GPU for it, so I can support Mojave. There's a lot of GTX 680's for sale. I found one called "Classified" with 4GB RAM for approx $50 which seems like a decent price (2GB's are more expensive...). There are also 780's with 3GB(?) that cost around $80, which is also fine. Searching around I can't seem to find a EFI firmware for the 780, but there seems to be one for GTX 680? Especially this thread seems promising, but I can see some that have problems with the firmware and newer OS X versions...? 1. Does it support Metal? 2. Is a firmware for 780 available? 3. Is a firmware for 680 4GB "Classified" available? (what is Classified anyways?) 4. Do I need to replace the ROM chip like I had to with my 2008's GTX 285? Thanks! Update: The 4GB classified version is gone... But there are a bunch of different 680’s and 780’s at roughly the same price ($50-$100). Would appreciate ant thoughts on the matter. I love the cMP, and it would be great to be on Mojave rather than El Capitan, and single 6 core HT rather than dual quad core (less heat/noise).