What is this temperature? CPU core? MB temp?
The Core i7 930 can run perfectly fine up to 100C, although I wouldn't feel too comfortable if it started hitting 80C. This is when under full load, not sure if your temperature is idle or partially loaded or?
Realtemp and coretemp are good monitoring programs, they can monitor each core's temperature for your processor
It is a good idea to clean the clase fairly regularly, to prevent any major build up of dust. You will also benefit from it being quieter