No more than 107Mhz, in the 790i above that speed the GX2 start to freeze when overlocked..
An important tip for Nvidia 790i Chipset: try to maintain the HT Mutiplier at 4x / 4x and the SPP <-> MCP Ref clock at least at 230Mhz, that will give a big boost on system tests, much higher than PCie speed in fact ..
:yepp: