GhislainG :
Are you sure he didn't have two gt 9500s each running a separate monitor or the second one used for something else? I can't find anywhere in the specs that SLI is supported; besides the Intel chipset does not support SLI.
"Next-generation dual and quad-core Intel® Xeon®
processor and chipset technology help enable your
staff and business to accomplish more in less time.
With dual Gen2 PCI-e interfaces, the HP xw6600
leverages an architecture than can deliver up to
twice the graphic performance of previous systems.
Add more visual capability and flexibility with the
HP xw6600’s support of up to four 3D displays or
up to eight 2D displays. And, with an energy-wise
system design you can help lower your energy
consumption and reduce your power costs with
80 watt processors and an 80 PLUS efficiency
power supply."
This was taken off the xw6600 PDF Manual
What do you think?