>> Building fast X server for PX product line is very difficult, indeed,
>> ULTRIX faq recommends to replace PX with TX for moderate 2D rendering
>> performance.
>
> I can confirm this - using the Ultrix X server on a PX was similar
> performance to using a plain CFB (PMAG-A) graphics card.

PX framebuffer memory is inaccessible from processor and PX rendering
engine (it runs very fast itself) is controlled by 'command packet'.
Due to the extremely tight bandwidth of the communication channel,
transfering 2D images into PX framebuffer behaves as a real bottom
neck.

Given the fact how much modern X desktops depend on 2D image loads
(think of facy animated browsers), PX is not an attractive hardware
for moderate X server environments.

Long time solution is to acquire HX (PMAGB-B) card.  It's as cheap as
$10 on eBay.

Tohru Nishimura