Supercomputing in Queensland 1993
If the 1970s and 1980s were the age of discovery about computers and information technology by universities and research organisations then the 1990s were perhaps the age of the Internet and Supercomputers.
CSIRO Computing History notes that by 1991 an arrangement for the joint supercomputing facility at Leading Edge Technologies (Cray X-MP) and CSIRO (Cray Y-MP in 1990) was not going to survive. A proposal by Cray Research led to the installation of a new CSIRO Cray Y-MP 4E at the University of Melbourne in August 1992 .
The CSIRO Cray at Leading Edge Technologies was shut down in February 1993 and transferred to the University of Queensland. The machine was a Cray Y-MP 2D/2-16, S/N 1409, 2 CPU rated at 666 MFLOPS (Mega FLoating points Operations Per Second), 128 MB ECL 15 nS memory, 256 MB MOS memory (slower) and 10GB disc at 96 Mbps.
It was certainly a good upgrade at the time from an IBM 3081 because the demand for engineering computation was increasing rapidly at UQ. The 3081 was not oriented to engineering processing, which often requires significant manipulation of floating point data. The 2 CPU 3081 likely had a capacity of about 20 MFLOPS. I was not aware of the exact contractual arrangements for the acquisition of the Cray, but I do recall that power consumption hadn't been considered in the 'How would you like a Cray?' conversation. UQ required considerable upgrades to the incoming computer room power supply. The IBM 3081's 25 kW power consumption was dwarfed by the Cray's 100 kW, which used ECL technology (a type of circuit that enables high performance).
The Cray was replaced in 1995 by a Silicon Graphics system rated at 6.4 GFLOPS.
Cray Y-MP installed at Prentice Computer Centre, The University of Queensland, 1993
Photo The Courier Mail 28 Sep 1993
Cray with covers off

Cray Y-MP modules, ECL (Emitter Coupled logic) which traded high power consumption for fast switching.
Each module had four boards mounted each side of the two copper plates, which were cooled with freon.
The chips were an ECL gate array designed by Cray which gave the Y-MP a 6 nS CPU clock cycle.
IBM 3081
The IBM 3081, that the Cray Y-MP replaced, used an equally impressive technology that was designed in the late 1970s.
A CPU consisted of 24 TCMs (Thermal Control Module), each of which contained 100+ chips, of approximately 700 switches per chip. The TCMs dissapated ~330 watts of power. They were helium filled and water cooled.
The chips were soldered upside down onto the ceramic substrate which contained up to 33 layers of wiring. This was TTL (Transistor Transistor Logic) technology, similar to the 74xx series of IC's widely available at the time. This architecture enabled a CPU clock cycle time of 26 nS.