I have a T1000 and X4100. The fans on the x4100 slow down following the initial boot up sequence. The T1000 fans; however, seem to run always at high speed, with lot of noise. Is this the normal behavior for the T1000?
Indeed, those specifications are for perfectly acceptable co-existence.
Glance at the chart I found at Wikipedia:
For you to actually know what the system is doing, you'll need a meter.
Guessing wouldn't be an accurate way to measure.
If you are in North America, go to Radio Shack for their #33-2055 unit.
If your T1000 is malfunctioning, you'll need to get Sun to repair it per its warranty or your service contract.