Never hurts to load the SDR's again, but I would start by running SELVIEW and checking the SEL log to see what is causing the high speeds.
(no SDR's loaded would do it, but it sounds like you did load then already)
Other options include CPU over heating due to Heatsink installation
Incorrect fan headers connected
a really hot server room
air inlets or outlets blocked.
BMC not functioning (you should see error messages when the BMC / SELVIEW / SDR try to flash)