It was the successor to "guTS" (Gigahertz Unit Test Site) and the purpose of both was to build a processor able to reach very high frequencies.
Project work was conducted by fewer than twenty engineers over a course of two years.
The idea was to use aggressive circuit design techniques, a carefully crafted floorplan and microarchitecture while keeping a short six stage pipeline.
While guTS only supported a subset of about 100, mainly integer instructions, of the PowerPC instruction set, Rivina used the complete 64-bit PowerPC specification including dual precision floating point and address translation.
The processor comprised over 19 million transistors, manufactured using IBM's CMOS 7S, 0.22 μm copper fabrication process.