It appears that an Russian based enthusiast that ,Big_Sam, had managed to get SLi working on an Intel chipset board. By using his ASUS P5WD2 Premium, flashed to BIOS version 0519, and switched “PCI Express 4x” mode for the second graphics slot from the BIOS. Then, connected the boards using SLi connector and installed ForceWare 66.72 drivers dated October, 2004. He got 2 pieces of 6600GT to work in SLi mode, but with a very restricted amount of applications supported.

Although ATI’s CrossFire multi-GPU technology support was officially
implemented for the 955X chipset, operation of two NVIDIA GeForce graphics cards
has been still impossible for the Intel core logic solutions. But even though
there is no official support for the SLI technology on core-logic sets from
Intel Corp., some enthusiasts still manage to make NVIDIA’s multi-GPU work on
Intel 955X-based mainboards.
 

Enthusiast Manages to Start the SLI on Intel 955X
 

A Russian hardware enthusiast from the forums of Overclockers.ru web-cite has
managed to enable SLI support on ASUS P5WD2 Premium mainboard. In order to make
two NVIDIA GeForce 6600 GT work in SLI tandem on the ASUS P5WD2 Premium, the
enthusiast known as Big_Sam flashed BIOS version 0519, set “PCI Express 4x” mode
for the second graphics slot from the BIOS, connected the boards using MIO
connector and installed ForceWare 66.72 drivers dated October, 2004, with SLI
benefits available in a very restricted number of applications.
The latest BIOS version 0519 for this mainboard officially enabled only ATI’s
multi-GPU CrossFire support, but, apparently, also allows running the platform
built on it in the SLI mode provided that a special NVIDIA ForceWare drivers
that lack check capability for supported platforms are installed.
Having installed a pair GeForce 6600 GT graphics cards in with Intel Pentium
4 660 processor and 1GB of memory, the experimenter managed to somewhat improve
the system performance. In 3DMark03 testing suite he reached 13 427 points, or
50% higher compared with what a single GeForce 6600 GT graphics card could
provide.
 

Drivers Limit Platform Support
 

Theoretically, there are no technical problems with enabling operation of
CrossFire or SLI multi-GPU technologies on any applications that have two PCI
Express slots for graphics cards, but developers of CATALYST and ForceWare
drivers have implemented functionality that checks whether a particular platform
has been verified by the driver development. In case a platform is not
officially supported, the driver does not allow multi-GPU configuration to
operate.
 

An ASUS representative is reported to have said that at this point all the
questions about SLI support on Intel’s chipsets are solely up to NVIDIA: there
are no hardware limitations in Intel chipsets or mainboards based on them that
could prevent from having SLI up and running.
 

ForceWare drivers Release 65 were released in October, 2004, to support
multi-GPU SLI technology, graphics cards with 512MB frame-buffer, improved
DirectX 9.0c and OpenGL performance as well as enhanced support for certain
video capabilities and HDTV.
 

The drivers enabled SLI operation on both NVIDIA nForce4 SLI as well as Intel
E7525 platforms, but while the former became popular, the latter was used only
by Alienware in a handful of systems it managed sold. It is unclear whether the
driver did not have an ability to check for supporting platform, or just checked
for physical availability of two electrical PCI Express x16 slots. In addition
to ForceWare drivers 66.72, which are, according to some web-sites, WHQL
certified, there is also version 66.93, which was officially released by NVIDIA
Corp.