Abstract: A cryostat cooling system cools the central processor (CP) circuit boards of a computer to enhance the performance of the electronic components of the central processor. The cryostat includes a pair of concentrically positioned circular cylindrical shells. The inner shell is suspended from the outer shell by a thin (small cross-section) thermal isolation support ring. A vacuum chamber is formed between the inner and the outer shells. The top of the inner shell is covered by an inner shell top plate having a pair of openings through which the CP boards are inserted. A pair of containment vessels are mounted below the inner shell top plate to receive the CP boards. An inlet supply tube is connected to the containment vessel to supply liquid nitrogen. Overflow vents permit excess liquid nitrogen and nitrogen gas to flow from the containment vessels into the interior of the inner shell.