I havent tested any of the 6900 series, but 7000 series do not work. I believe GTX 580 and HD5870 to be the fastest that work. For AGP it is the HD3850 followed by the HD4760. The HD4760 might be faster when AA/AF is applied in certain situations.
it seems like Radeon PCI-e 2.1 cards do work, as all cards from the 5000 series on are 2.1 cards, maybe even some 8000 and 9000 series cards work. Nvidia didn't make any 2.1 cards, they went straight from 2.0 to 3.0
https://en.wikipedia.org/wiki/List_of_AMD_gra … rocessing_units
https://en.wikipedia.org/wiki/List_of_Intel_g … rocessing_units
https://en.wikipedia.org/wiki/Comparison_of_N … rocessing_units
Also, it looks like some of the higher 6000 cards do work as per this thread
https://forums.anandtech.com/threads/asrock-4 … .311715/page-38
Check out pages 36-37
"All, I just installed a Powercolor dual fan 1GB variant of the Radeon HD 6950 and it is running fine on my Asrock 4coredual-sata2 r2.0 with the 2.20A BIOS, an Intel E5700 Pentium Dual Core overclocked to 3.6Ghz, 2x2GB Patriot DDR2-800 5,5,5,15 running at DDR2-640 4,4,4,12, Creative Sound Blaster Live PCI sound card, a Seagate 1TB 7200RPM HD, and a Viewsonic P225F with Windows 10 Pro 64-bit. I picked this up at Newegg for $70.00, with a $20 rebate and an instant $10 Newegg card. I have a Rosewill 530W single rail 12V 41amp PS. There should be no issue as far as power is concerned. Unfortunately, I had to give up my IDE ports on the motherboard for my DVD-ROM/Writer drive due to the 10.83" length of this card. It is absolutely huge. I almost never use a ROM drive anyway. Just an FYI.
Update, I was able to connect a PATA DVD/RW drive with a standard ribbon cable to the motherboard with no clearance issues with the card. I was using one of those SATA/PATA-IDE adapters plugged into the motherboard and a SATA DVD/RW drive. It was way too tall to fit under the card. The ribbon cable just fits.
I also was able to swap out the 1GB card with a Sapphire 2GB HD 6950. It powers down to 250 core 150 memory and runs much cooler than the Powercolor product that stays at 450 core and 1250 memory (I believe) for some reason. There is a 12 degree difference delta between these cards because of this. The Sapphire card is idling at 32C with 30% fan, whereas the Powercolor is idling at 44C at 30% fan. I will fiddle more with the Powercolor card to see if I can get it cooler. I am using MSI Afterburner for both cards with a custom fan setup."
"The 6870 is a PCIE 2.1 card and that works on my 4CoreDual-SATA2 R2.0 board.
I'm not sure if masterofunivers is running the last bios update from PC Treiber, that may have provided support for PCIE 2.1?"
"Thanks for that info Masterofunivers.
I followed your instructions and it all worked out well, I got AMD 4770 card drivers installed and the kids are playing their favourite games again on this 4CoreDual-SATA2 R2.0 rig with Windows 10 64bit. I also tried out my other card AMD 6870, it worked OK also on this motherboard with Win 10 64bit.