>>>> In theory - if you succeed to find (or make) some AGPx1->PCI riser
>>>> [...] you can try PCI card in AGP slot

>>> I see if I can find it.

>> Good luck. I've never seen such thing.

> xserve G4 have similar 90° riser.
> You need AGP 1x v1.0, 3.3V and PCI v2.1 3.3V 66MHz.

Very nice find, I wasn't aware of this riser. The AGP side seems compatible with the Pegasos 2 and the (64-bit) PCI side seems compatible with (32-bit) Radeon HD cards. Would be cool if someone tried in his Pegasos and compared performance with the same Radeon HD card installed directly in 33 MHz PCI slot.