HKEPC has stumbled across a few interesting findings
regarding the non-SLI compatible nForce 5 variants. A motherboard manufacturer
by the name of Magic-Pro has an nForce 550 motherboard that is compatible with SLI—the
A2N5. This is quite strange as NVIDIA doesn’t certify the nForce 550 for SLI
operation but somehow Magic-Pro has found a way around it. The A2N5 has two
full length PCI Express x16 slots with eight lanes routed to each slot—similar to
an nForce 570 SLI setup. NVIDIA drivers were able to detect two graphics card
and open up SLI options on the Magic-Pro A2N5.
The A2N5 was than compared to other nForce 550 motherboards
and it was found the nForce 550 chipset lacked a resistor that was found on
other nForce 550 core logics. This is similar to how nForce 4 Ultra boards
were modified for SLI compatibility. After further examination HKEPC did
further experimentation with an MSI K9N Platinum nForce 570 motherboard. The K9N
Platinum nForce 570 motherboard appeared to have the resistor soldered in place
that prevented SLI operation. It was removed but SLI operation was still
disabled on the motherboard.
There was more to just unsoldering a single resistor to
enable SLI operation on nForce 550 and nForce 570 chipsets. A couple more
resisters had to be removed around the second PCI Express x16 slot to divide
the sixteen PCI Express lanes to both slots. After removing more resistors
HKEPC achieved success and was able to mod the MSI K9N Platinum nForce 570
motherboard to allow SLI. SLI performance on modified nForce 550 and 570
motherboards came out identical to a regular nForce 570 SLI motherboard.
nForce 550 and 570 users shouldn’t rejoice quite yet.
Although the modification appears to work well, don’t expect it to be working
for too much longer. If previous nForce 4 Ultra modifications is a hint of
things to come expect NVIDIA to find a way to prevent SLI support on
uncertified motherboards. While this modification is a hard mod the chipset ID
still remains the same so expect NVIDIA to use this to its advantage. nForce 570 and 570 SLI only have a price differential of about $20 right now, so for those not handy with a soldering iron, the modification might not be worth the elbow grease either.
quote: And that software could check a serial number burned into a permanent ROM chip required on every motherboard (or in each chipset)