The CDC 7600 was the Seymour Cray-designed successor to the CDC 6600, extending Control Data's dominance of the supercomputer field into the 1970s. The 7600 ran at 36.4 MHz (27.5 ns clock cycle) and had a 65 Kword primary memory using magnetic core and variable-size (up to 512 Kword) secondary memory (depending on site). It was generally about ten times as fast as the CDC 6600, and could deliver about 10 MFLOPS on hand-compiled code, with a peak of 36 MFLOPS. In addition, in benchmark tests in early 1970 it was shown to be slightly faster than its IBM rival, the IBM System/360, Model 195. When the system was released in 1969, it sold for around $5 million in base configurations, and considerably more as options and features were added.