While we have had great success with the 4870 and 4890 via the "rom stitch" pioneered by Pipomolo42, we have had ZERO (0) luck with Nvidia.
Today I decided to start simple. After reading about 7800s working while 7300s were in, I decided this would be a good combo.
I got an XFX 7800 and an XFX 7600. I chopped the EFI part of 7300GT ROM out and stitched it with the XFX cards, Using the Pipomolo method. I was able to get BOTH cards to do the grey boot screen, perfectly clear from artifacts. Oddly, the 7600 does it at a very low res...as if it hasn't properly gotten EDID from display. The 7600 then stops displaying after spinning grey screen, never showing blue.
If you have another card in to view from, the 7600 shows up in profiler as if it is working, but no luck getting displays to fire. (gonna try the splitter)
The 7800GT on the other hand is almost fully functional.
It shows grey boot screen and boots into OS X 10.6.2 just fine.
Sometimes the cursor is a messy square, or invisible, but otherwise card seems to function fine.
My feeling is that this seems to prove that EFI ROM is parsing the PC BIOS enough to find boot clocks and ram timing. I doubt that the G70 7800GT and the G73 7300GT could run same ROM, so for EFI to display clear screen, it seems to be getting values from PC BIOS.
Next I will try 7800GTX.
In case you wonder why I bother with old cards nobody cares about...I am hoping to learn enough to get G92 and GT200 series cards "sewable".
If anyone has a 1st Gen Mac Pro and a 7800GT with a 128K ROM chip and would like to confirm working single card ROM, please speak up.
Today I decided to start simple. After reading about 7800s working while 7300s were in, I decided this would be a good combo.
I got an XFX 7800 and an XFX 7600. I chopped the EFI part of 7300GT ROM out and stitched it with the XFX cards, Using the Pipomolo method. I was able to get BOTH cards to do the grey boot screen, perfectly clear from artifacts. Oddly, the 7600 does it at a very low res...as if it hasn't properly gotten EDID from display. The 7600 then stops displaying after spinning grey screen, never showing blue.
If you have another card in to view from, the 7600 shows up in profiler as if it is working, but no luck getting displays to fire. (gonna try the splitter)
The 7800GT on the other hand is almost fully functional.
It shows grey boot screen and boots into OS X 10.6.2 just fine.
Sometimes the cursor is a messy square, or invisible, but otherwise card seems to function fine.
My feeling is that this seems to prove that EFI ROM is parsing the PC BIOS enough to find boot clocks and ram timing. I doubt that the G70 7800GT and the G73 7300GT could run same ROM, so for EFI to display clear screen, it seems to be getting values from PC BIOS.
Next I will try 7800GTX.
In case you wonder why I bother with old cards nobody cares about...I am hoping to learn enough to get G92 and GT200 series cards "sewable".
If anyone has a 1st Gen Mac Pro and a 7800GT with a 128K ROM chip and would like to confirm working single card ROM, please speak up.
