Where on the web can I find information on how to build a computer
graphic card using an off-the-shelf GPU, such as an Ati Radeon 9800 or
a nVidia GeForce FX 5900? Info on GPUs that are a couple of years old
is okay too but I am hoping to get something detailed enough so I
could tweak and swap things on the card and get it to work with decent performance.

Hi ggc-ga,

  Since no one has tried to answer your question, I am atleast
giving my comments:
You need atleast the following information to make a decent
graphics card(assuming you have expertise in high speed pcb
chip design and have the specialized tools/equipment required to handle
the unique packaging such as flip chip/ball grid array).
-Detailed specification of the graphics chip(Electrical,Physical
 and Mechanical)
-Few application notes.
You should be able to get both of this from the manufacturer.

Another easier way to comeup with a better graphics card, is to
think about mods/tweaks to existing high end graphics cards using
the gpu's of interest.  Here again you have to figure out reading
the detailed specs of the gpu, understand the design, try to figure 
areas of improvement.  You should find lots of tweaks in forums meant
for overclocking, extreme gaming etc.

If you really want to design a good graphics card, but do not care
about the cost, you may want create a design that will use multiple
gpu's for which the specs are available in detail.  You could probably
use any of the high speed fpga's in your glue logic.

Best of luck.

Regards
ldavinci-ga

Hi ldavinci-ga,

Appreciated your comments - thanks!

I've got a fair amount of knowledge on high speed PCBs and chips over
the years fiddling stuff so I think I should be good enough to get
started. For GPUs, my problem is the detailed specifications and
application notes are not available - the GPU makers don't deal with
individuals. There has got to be someone out there who got some of
these toys figured out.

I noticed there were water-cooled over clocked graphic cards out there
and these are really cool. But I am hoping to do something myself - in
fact your suggestion of using multi-GPUs are very interesting. GPUs
are just massive (but specialized) processors themselves, right?

I will keep looking ...

Regards,


ggc-ga

Hi  ggc-ga,

  I do understand the difficulty in getting the gpu specs. from the
manufacturer.  But you could think about an alternate route of
either contacting developers of opensource projects(such as XFree86),
who might have been handed the specs for the development of an accelarated
driver. You could also try approaching opensource friendly manufacturers 
directly, who knows what you can get!.

  I do understand most of the tweaks/mods are about cooling,s/w driver hacks,
you might still find few board level mods, except that they are hard to come
by(since the risk of damage is very high).

  GPU's for sure are complex beasts(more of an io optimized complex risc
processor, with lot of onboard/external memory). So, for a graphics card
with multiple GPU's you probably should start with a simpler/older GPU.
But it could be a good learning experience that should eventually lead
you to your ultimate quest of a DIY graphics card that surpasses the
commercially mass marketed ones in performance.

Regards
ldavinci-ga

Hi ldavinci-ga,

Thanks again for the follow up and the tips. Really enjoyed this exchange.

I will continue digging and hope I will find what I need eventually.  

Have a nice weekend!

Regards,


ggc-ga