I figured it'd be helpful to start a new thread that includes not instructions, but just a list of Radeon 4870 cards that can be flashed to work in Mac Pros. I'll update the list as more news comes in.
Note that using PC cards requires the use of a special cord that uses a smaller PCIe six-pin connector found only in G5s and Mac Pros. You can cut the cable, buy the correct plug, and make your own cable, but I won't go into that here. If you want to buy the cable and live in the US, AMD sells them at this link:
http://shop.ati.com/product.asp?sku=3280778
ATI Reference 4870 (512 MB)
Sapphire 1st Gen 4870 (512 MB) (102-B50701-10-AT)
Sapphire HD4870 512M GDDR5
PCI-E DUAL DVI-I/TVO
PN 288-XXXXX-XXXXX
SKU# 11133-03-20R
At Newegg: http://www.newegg.com/Product/Product.aspx?Item=N82E16814102810
HIS Radeon HD 4870 512MB GDDR5
HIS S/N: H081230050
PN: H487F512P
UPC is 4895139000740
At tiger direct:
http://www.tigerdirect.com/applicat...ffiliateID=X3Th4gZi_iQ-ZYbigRtlMH3VoAJ2J_W5CA
More on this as it develops, but it appears that these cards work with the Mac EFI ROM without modification. The majority of cards will not and require modification using the process as follows.
Onto modification of PC 4870 cards to work properly in a Mac Pro: (by pipomolo42)
This will necessitate a PC to extract the card's ROM. You will also need the Mac 4870 ROM posted in the now lengthy thread about this.
1. Get the 128k vgabios of your PC card. (pc4870.rom) Get the Mac 4870 ROM, and get the fixrom.py script pipomolo42 prepared for us.
2. Run the following commands in a shell.
According to pipomolo42, these commands will extract the EFI part of the Mac ROM, get the number of 512 byte blocks of the BIOS part of the PC ROM, convert that to a size in bytes, then add the EFI part right after the BIOS, then fixes the last ROM indicators and checksums.
3. Flash the ROM.
A huge thank-you goes out to netkas, The Rominator, and pipomolo42 for coming up with these and figuring out the process.
Some other things to keep in mind:
You will need the Apple specific PCIe cables to drive this card, which can be purchased from ATI's site (U.S.). Some PC 4870s require 8-pin PCIe taps. Avoid these.
Is it possible to use a PCIe 6-pin splitter (if so, which should be used?) to drive the 4870 on its own from one of the motherboard sockets, as long as it splits out to the specific cables?
Apple's 4870 drivers are in a beta state right now (or at least incomplete). This might explain the disappointing performance of the 4870 relative to the 8800 GT in the Nehalem benchmarks posted by Barefeats. Of note, the 4870 still seems to perform better in Harpertown Mac Pros. 10.5.7 should resolve the situation. And it appears to be close to release.
For some reason, it looks like one of the DVI ports is not dual-link - single link only. Could be a dealbreaker if you're dying to run two 30" monitors.
The 1 GB cards work. The 4870x2, as of now, does not. It requires more elaborate ROM wrangling that has not yet been figured out.
Analog output apparently is not working from these cards. Shouldn't be an issue unless you're dying to use a CRT or a VGA cable.
Netkas has graciously put a walkthrough up here:
http://netkas.org/?p=90
Any clarifications or updates will be edited in here.
One other note of interest: eBay user Bruinmacs, who is known for selling working flashed PC cards, has put a 4870 up for sale. Unfortunately, it's pricey ($335+shipping). His items can be found here:
http://search.ebay.com/_W0QQsassZbruinmacs
Note that using PC cards requires the use of a special cord that uses a smaller PCIe six-pin connector found only in G5s and Mac Pros. You can cut the cable, buy the correct plug, and make your own cable, but I won't go into that here. If you want to buy the cable and live in the US, AMD sells them at this link:
http://shop.ati.com/product.asp?sku=3280778
ATI Reference 4870 (512 MB)
Sapphire 1st Gen 4870 (512 MB) (102-B50701-10-AT)
Sapphire HD4870 512M GDDR5
PCI-E DUAL DVI-I/TVO
PN 288-XXXXX-XXXXX
SKU# 11133-03-20R
At Newegg: http://www.newegg.com/Product/Product.aspx?Item=N82E16814102810
HIS Radeon HD 4870 512MB GDDR5
HIS S/N: H081230050
PN: H487F512P
UPC is 4895139000740
At tiger direct:
http://www.tigerdirect.com/applicat...ffiliateID=X3Th4gZi_iQ-ZYbigRtlMH3VoAJ2J_W5CA
More on this as it develops, but it appears that these cards work with the Mac EFI ROM without modification. The majority of cards will not and require modification using the process as follows.
Onto modification of PC 4870 cards to work properly in a Mac Pro: (by pipomolo42)
This will necessitate a PC to extract the card's ROM. You will also need the Mac 4870 ROM posted in the now lengthy thread about this.
1. Get the 128k vgabios of your PC card. (pc4870.rom) Get the Mac 4870 ROM, and get the fixrom.py script pipomolo42 prepared for us.
2. Run the following commands in a shell.
Code:
dd if=4870.ROM of=efi.part bs=1 skip=63488 count=49152
blocknum=`printf %d "'\`dd if=pc4870.rom bs=1 skip=2 count=1 2>/dev/null\`"`
size=$(($blocknum * 512))
dd if=efi.part of=pc4870.rom bs=$size seek=1 conv=notrunc
python fixrom.py pc4870.rom pc4870.romAccording to pipomolo42, these commands will extract the EFI part of the Mac ROM, get the number of 512 byte blocks of the BIOS part of the PC ROM, convert that to a size in bytes, then add the EFI part right after the BIOS, then fixes the last ROM indicators and checksums.
3. Flash the ROM.
A huge thank-you goes out to netkas, The Rominator, and pipomolo42 for coming up with these and figuring out the process.
Some other things to keep in mind:
You will need the Apple specific PCIe cables to drive this card, which can be purchased from ATI's site (U.S.). Some PC 4870s require 8-pin PCIe taps. Avoid these.
Is it possible to use a PCIe 6-pin splitter (if so, which should be used?) to drive the 4870 on its own from one of the motherboard sockets, as long as it splits out to the specific cables?
Apple's 4870 drivers are in a beta state right now (or at least incomplete). This might explain the disappointing performance of the 4870 relative to the 8800 GT in the Nehalem benchmarks posted by Barefeats. Of note, the 4870 still seems to perform better in Harpertown Mac Pros. 10.5.7 should resolve the situation. And it appears to be close to release.
For some reason, it looks like one of the DVI ports is not dual-link - single link only. Could be a dealbreaker if you're dying to run two 30" monitors.
The 1 GB cards work. The 4870x2, as of now, does not. It requires more elaborate ROM wrangling that has not yet been figured out.
Analog output apparently is not working from these cards. Shouldn't be an issue unless you're dying to use a CRT or a VGA cable.
Netkas has graciously put a walkthrough up here:
http://netkas.org/?p=90
Any clarifications or updates will be edited in here.
One other note of interest: eBay user Bruinmacs, who is known for selling working flashed PC cards, has put a 4870 up for sale. Unfortunately, it's pricey ($335+shipping). His items can be found here:
http://search.ebay.com/_W0QQsassZbruinmacs
