Hey guys,
after spending some time with reading the threads concerning the Radeon HD 4890, I decided to try it myself. First the important information:
Maker: PowerColor
Model#: AX4890 1GBD5-UH
Full Product Name: PowerColor HD4890 Plus (Retail, 2x DVI, TV-Out) -> that's the product name which was used by the vendor here in Germany where i ordered the card
Item#: JCXOUA (Alternate, details: see URL below)
Core Clock: 900MHz
Memory Clock: 1000MHz
Output: 2 DVIs and 1 S-Video
Link: Link to Alternate (Germany),
Link to PowerColor,
Link to Newegg (according to the Model#)
The interesting thing about the card I received: it looks like the one kronoss received from newegg (pictures in
his thread). First thing i thought "Damn, they sent me the wrong card!". Also according to the pictures on the website of PowerColor it's a
PCS or
PCS+-version of that card, but not a
Plus. The backside of my card says "AX4890 1GBD5-UH" and also the box says "Plus". The difference to the
box on PowerColors' website is the sticker you also find on kronoss' picture (
Professional Cooling System, left below
DUAL DVI / HDMI). But this all are points I realized AFTER flashing a wrong ROM
Thank goodness I made a copy of the original ROM (didn't found anyone in Powertech's database) with GPU-Z. After the flashing process the Mac didn't boot and stopped with a red light stating a fail of CPU B on the mainboard. So I called a friend of mine telling him that we have to "repair" my broken HD4890. To make the long story short: after flashing a self-made ROM (big thanks to Peloche for his beautiful mindmap/guide creating custom EFI-ROMs) via a DOS boot-disc and with a PCI-card in the PC, the Mac booted in the usual way with grey apple-screen. In the end I installed the QE_CI-Package for 10.6.2 and everything is fine now

Works perfect under Mac OS and also in BootCamp. As second power source I use an ATI-cable (had one of these in the box of the Mac 8800GT, which is broken since a month now), got no error messages up to now ("Power cable not connected correctly" or something else). The only annoying thing is the cooler. Under heavy load he makes noise. It's acceptable, but it could be much lower. Unfortunately it seems impossible to mount a Accelero Twin Turbo, because of the condensators right to the big heatsink. Any suggestion for an alternate cooler would be nice
In the end I want to thank all those people who contributed their hard work in order to get 48xx-cards working on our beloved Mac Pro
As attachement I submit the original ROM (RV790PC) and the modified EFI-ROM (EFIROMFX).
MD5Sums:
RV790PC.bin: 9944bce9c7e633d240298311e99cc805
EFIROMFX.rom: 5896e871127e8855be2fa2d26f2fc195
RV790PC.bin.zip: c2ebc7e7e218d14c541b6efa1167ba82
EFIROMFX.rom.zip: e188fbb119627fa8b34e6d12ce4f6f4b