Our cryogenic cooled Pentium 4 system turned in a SYSmark 2000 score of 191, which is a normal score that can be expected of a 1.5GHz CPU. We did not change anything about the system itself, not did we run any part of the system 'overclocked' or in any other way out of specification. The only thing that is different from the other conventionally cooled systems is the fact that the Pentium 4 CPU is kept at -40C at all times. For those of you that are interested in how we obtained such low temperatures under full load. The cryogenic system uses a combination of peltiers, liquid cooling and vapor-phase refrigeration to be able to handle such heat loads at sub-zero temperatures.



Fig 8. The SYSmark 2000 benchmark score of the cryogenic cooled Pentium 4 system, which is about average for a 1.5GHz CPU.

The other configurations can be found in the table below, which also indicates whether a CPU and heatsink combination was able to finish the test run and whether it turned in a SYSmark 2000 score. We allowed the system to cool down for half an hour between test runs to get accurate results while the system case was closed for all tests and case temperature was in the 35...40C range at all times.

	Booted into OS?	Completed SYSmark 2000 run?	SYSmark 2000 score
CPU, no heatsink, no thermal paste, no fan	fail	fail	fail
CPU, aluminum heatsink, no thermal paste, no fan	success	fail	fail
CPU, aluminum heatsink, thermal paste, no fan	success	fail	fail
CPU, aluminum heatsink, no thermal paste, with fan	success	success	190
CPU, aluminum heatsink, thermal paste, with fan	success	success	190
CPU, copper base heatsink, no thermal paste, no fan	success	fail	fail
CPU, copper base heatsink, no thermal paste, with fan	success	success	190
CPU, copper base heatsink, thermal paste, no fan	success	success	190
CPU, copper base heatsink, thermal paste, with fan	success	success	190