Given that there was a space race and an arms race, it should be surprising to no one that there was also a supercomputing race. The Soviet Union's high-perfomance computing programs were, of course, shrouded in secrecy. The information here is, and sadly will probably remain, rather sketchy. Please send anything further to KevinK@acm.org.
Leonard Broukhis' BESM-6 Nostalgia Page contains a surprising wealth of information on this series of "high-performance" numerical computers, including source code for an emulator!
The SVS (1980) and Elbrus-B (1988) were successors to the BESM-6 machines, using relatively more advanced technology. For some strange reason, Moore's law never seemed to apply in the Soviet Union, however, and these home-grown machines fell further and further behind their western counterparts. Fortunately there was another solution...
Right up until the end of the Cold War, there was a brisk, if risky, traffic in American supercomputers and minisupercomputers to the Soviet bloc. The Soviets and their allies were, in principle, embargoed from importing anything much more powerful than an Apple II, but the profit motive, as Lenin noted, should not be underestimated. Machines were ordered for delivery to neutral third countries and delivered to unnamed warehouses or even farms. Machines were bought and resold several times in order to muddy the trail. The main clue to the manufacturers (and presumably the CIA) was that these machines were often ordered without a service contract. Obviously illegal procurement attempts were blocked by the US government, or by the supercomputer vendors themselves, but quite a few machines slipped through.