I asked Mike Harris, RedHat's XFree86 maintainer, a couple of questions regarding a conversation Spot and I were having on IRC regarding Spot's Voodoo5 card. I thought Mike's answer might be of interest to owners of 3Dfx based video cards, so I am posting it here.
I had seen somewhere awhile back that the XFree86 drivers only support using one of the chips on the Voodoo5. Is this correct?
Correct. Only one chip is supported for any Voodoo hardware. As such, a Voodoo 5 turns into a Voodoo 4 under Linux. SLI mode of the Voodoo cards is not supported.
IAre the maintainers working on a driver that uses both chips?
No. At the time 3dfx collapsed, the hardware level documentation of the Voodoo 4/5 was not publically available. Some of the DRI project members had the specs and had worked on the code, however it was not ever completed, and will never be completed now. I've talked with Darryl, and his opinion was that even if the specifications were available publically to the community, the hardware is sufficiently complicated that it would require direct communication with actual 3Dfx engineers in order to get it working in SLI mode.
Since 3Dfx no longer exists, and Nvidia holds all of that information now, it is highly unlikely that SLI will ever be supported on any 3Dfx hardware.
All 3D and 2D development of tdfx hardware has more or less frozen on the DRI, Glide3, and XFree86 sides of things. If anything, I fear the code will rot now until it is unusable.
One of the down sides to locked away information. ;o(
----end forwarded message----
Doesn't sound to good for any future development on the 3Dfx drivers. :'(