 It is similar to the VAX 8700, but is not upgradable to the VAX 8800.The VAX 8500, code-named ""Flounder"", is a lower-performance variant of the VAX 8550, with microcode used to insert nops during operation to limit performance.The VAX 8530, code-named ""Skipjack"", is an upgraded VAX 8500 with the nops removed for improved performance.