It depends on the multipliers available on the botherboard. If you have the Motherboard Manual handy, check and it should tell you the maximum speed it will support. If not, you might want to check the motherboard manufacturer's website to see if they have any information listed there!
This is determined by the particular motherboard model, there are 3 major revisions. The SE440bx supports a differient processor from the SE440bx-2, and there are 2 major versions of the SE440bx-2. The two versions of this board are determined by the serial number on the motherboard. The first SE440bx-2 motherboards were physically limited by the processor power supply that was built onto the MB. So your best bet is to go to intel's web site after getting your serial number off the motherboard, (which if your not sure where to find it intel's site will tell you where to find it)and compare it to what you have and the datasheets from them will be able to tell you what the largest processor the MB will handle is.
Have a good one Jonathan