[micrex22]

The GXT4500P (single GPU) and GXT6500P (dual GPU) were released in 2002 as 64-bit PCI-X cards for the RS/6000 platform, however they can also operate in a 32-bit PCI slot as well--obviously at a performance loss. They were generally paired with the T115, T117, T119 and T120 monitors, the T120 being a fairly famous cheaper substitute to the T220/221. Hilariously enough they're not compatible with all VGA monitors--including IBM's own L190, I suspect this is due to the way AIX and/or the GXT cards handle VGA signals. It's fairly common when dealing with old IBM video cards to experience some weirdness, for instance the microchannel XGA-2 cards can have display problems at different resolutions like 800x600 on certain CRTs; but that's getting a little off topic. Needless to say if you're running a VGA monitor, expect there not to be a seamless experience with *all* monitors.

Because it may come up or be wondered upon, the GXT135P was never designed by IBM and is in fact a Matrox GPU with PowerPC firmware. Therefore it does not run graPHIGS. XiG did release a 3rd party driver to this card for AIX to take more advantage of its capabilities and enhance a few things since IBM just slapped it in as an afterthought because it wasn't developed in-house like the 4500 and 6500. Reference: http://www.xig.com/Pages/Hdwe/Graphics/GXT135P.html
Please be advised XiG doesn't sell any of their souped up matrox AIX drivers anymore, so... that's the end.

• GXT4500P: graPHIGS, OpenGL 1.2
  
• GXT6500P: graPHIGS, OpenGL 1.2.1
  

I'm (guessing) the 6500 has a firmware update that allows it to support OpenGL 1.2.1 over the 4500's 1.2? Or perhaps it was deliberate by IBM? I'm not sure. At any rate because the card came out in 2002, the OpenGL versioning support is on the older side of things, unfortunately. IBM also lists 'X11' and 'motif' under the API section but... that's not really the same as OpenGL, graPHIGS, GLide, DirectX etc. Any card will run X11 afaik.

The GXT4500P and GXT4500P are only supported under AIX and not Linux (they require at least AIX 4.3.3 and higher), to my knowledge nobody was written any open source Linux drivers, or drivers at all. I am also not aware of how widespread graPHIGS usage was, I couldn't count a single person who has expressed usage of the API. I wouldn't even have known it was a thing without looking at the spec sheets for these cards.

Systems these cards were approved to run in:

• RS/6000 7044-170 (both)
  
• RS/6000 7044-270 (both)
  
• RS/6000 7043-150 (GTX4500)
  
• RS/6000 7043-270 (both)
  
• IntelliStation POWER 9111-285 (both)
  
• IntelliStation POWER 7047-185 (both)
  
• IntelliStation POWER 9114-275 (both)
  
• IntelliStation POWER 9112-265 (both)
  

Eventually IBM just re-used the same old GXT4500 and 6500 cards in the later IntelliStation POWER series and never refreshed the card platform, meaning these were the last for the AIX CAD cards. I'm guessing this was due to the high amount of R&D and cost to design and build these cards and the shrinking market for them; not all IntelliStations sold were used for CAD so that would make the market demand for these cards even less than the amount of machines sold. That does mean they were actively produced from 2002 all the way up to 2009: which is impressive as I imagine the memory modules would have gotten fairly difficult to source at that point. They wouldn't have actively manufactured the old memory ICs in 2009, unless IBM still had contacts for it.

According to IBM's marketing at the time:

Ideal for mid- to high-end MCAD, front-end graphic processing and other floating-point-intensive applications, the IntelliStation POWER 265 with GTX6500P graphics convincingly beats comparably configured HP 3700 and Sun Blade 1000 workstations in CATIA V4 benchmarks.2 A new generation of IBM 3D graphics technology—the GXT4500P and GXT6500P with 128MB unified frame buffer—delivers up to a 15-20% boost in performance over the GXT4000P/6000P adapters, at a new lower price. Both PCI graphics accelerators feature analog and digital output, 24-bit double buffer with resolutions up to 2048 x 1536 at 60 Hz, and API support for OpenGL 1.2.1, graPHIGS, and X11. Advanced 3D features include an on-board geometry accelerator, hardware lighting, IBM IntelliStation Workstations: Performance on Demand 24-bit Z-buffer, 4/8-bit overlay, 8-bit double buffered Alpha, 8-bit stencil, up to 110MB texture memory, dual texture, and 3D texture. The GXT6500P has an additional geometry and lighting processor that further increases performance.

2. Jan. 2002 CATIA V4.2.2 R2 TAGITT results. Each system configured with 512MB memory, 9.1GB SCSI hard drive, and CD-ROM drive. HP 3700 at 750 MHz with fx 5 or fx 10 pro adapter; Sun Blade 1000 at 900 MHz with Expert3D adapter. All performance data contained in this publication was obtained in a specific environment, and is presented as an illustration. The results obtained in other operating environments may vary. http://www-1.ibm.com/servers/eserver/pse...urces.html

In terms of running these adapters, you can in fact run *two* GXT4500Ps in an IntelliStation POWER 185 with dual monitor support, however only one GXT6500P can be ran in the system at any given time. This restriction could change depending on other systems, but I only have the one and limited experience outside the 185 (which is probably the oddest in the bunch, anyways). If you're settling for the anemic Matrox GXT135P, you can stuff a total of four of them in a system and (presumably) get quad monitor support out of AIX! Some day in the future I may consider two GXT4500Ps if I want to dabble in AIX mutli-monitor support, that is if my 185 ever becomes a workstation I like to use on a daily basis.