The Cray T3E


Picture of T3E
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This is a front shot of our T3E. This is an air-cooled machine in the maximum configuration possible for air-cooled machines, 136 processors. The six cabinets each have 6 slots (see below), Cabinets are numbered from 0 to 5 left to right. Cabinets 0 and 3 contain a clock board. All other 4x6+2x5=34 slots contain a processor module. Each module mounts 4 processors, hence the total number of 136 processors.

Picture of T3E front side
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This is a front shot into one opened cabinet. You see essentially six power supplies (3.3V), one for each of the six slots within the cabinet. The small panel top left is environmental and power monitoring. The big switch at the bottom switches between 400 VAC or 208 VAC three-phase supply.

Picture of T3E back side
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This is a backside shot into one opened cabinet. You see the six slots, where the left slot carries a clock board, and the other five slots carry a processor module. The boards are all vertically arranged. Like in the liquid- cooled models the PCB is mounted onto a cold plate. The cold plate, however, is not cooled by ciculating cooling liquid, but has a large heatsink mounted on the other side (where there is another processor module for the liquid cooled machines). This enables the vertical air flow through the machine to remove the heat.
On the top side and on the bottom side of the modules you see the torus wiring. On the bottom we have additional Gigaring wiring, connecting each processor module via Gigaring to the I/O subsystem.

Picture of Torus Wiring
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This picture shows the top part of the torus wiring. Each module has a row of connectors on the top and on the bottom. All torus connections are wired via these connectors. The wiring extends in between cabinets. The particular cabinet shown has no neighbour to the right, to torus flatcables extend only into the left neighbour cabinet.