Hello there

Recently, i got this nice set of 8 cards for MAC, which is included:
- 2 Geforce Ultra 5200 64Mb 128 bit.
- 3 Radeon 9600 Pro/XT 64/128/256mb each.
- Some green Radeon... unfortunately dead/ no detect.
- and a bonus. 2 pcs Geforce 6800 Ultra DDL MAC edition.

So the goal is to run 6800U into PC.
I checked all available online info, and there is not too much of it. A couple failed attempts to run the card from PC. So let's try it.

I inserted the card in to my AGP Pro slot of PC and start it. PC has no signs of life, fan on card not spinning.
Let's check what we missing here.
- vmem 2 phases 2.0v check ok.
- nvdd 3 phases 1.2v check... fail.
- check power source on nvdd mosfets. 3.0v present. This is too low.
Digging deeper i noticed one strange thing. Usually MAC cards has an ADC monitor port connector and an ADC power socket pins to motherboard side.
This geforce has no ADC Monitor but has ADC pins. So i attaches some voltage to ADC pins and trace where is goes.
And it goes to NVDD power rail.

So this Geforce using ADC 25V power rail to supply a voltage to NVDD. ADC 25v --> 1st buck converter down to 12V --> A very big COIL 😀 --> NVDD 3 phase buck converter

First i attached 25v from my lab source to ADC pins and started the PC.

Yes it's has been detected by nvflash.

I flashed with 6800Ultra bios and run into Windows. And it's been detected correctly, installed the drivers and...

So i flashed to 6800GT
The warning is gone, and card works as expected.

I modded 6800GT bios to run on ULTRA speed (425/550) and it's running fine. GPU has all 16 pipes, VRM has full 3 phases for GPU and 2 phases for memory. So this is ULTRA.

Now, i do not want to run the card with 25V attached. What if i can attach 12V directly to output of 1st buck converter.

And it's working!

So, all we need is to attach some power connector to the point before the BIG COIL. Let's do this:

Now i have fully working Geforce 6800U DDL MAC Edition running on PC.

(here should be a picture of running 6800 but i ran out of limit of attachments)

Now. Downsides:
- DVI does not work. both. Probably it may be fixed by doing some modding work with nvidia bios.
- DSUB output is working but it's a little bit blurry. Higher resolution - more blurry. And i understand this, most likely APPLE does not have a DSUB monitors for this at all -)
- Weird PCIE external connector must be attached to the card.

ps
both 6800U cards are working fine.