Cooling and Timing Tests of the ATLAS Fast Tracker VME boards

The Fast Tracker Processor (FTK) is an ATLAS trigger upgrade built for full event, low-latency, high-rate tracking. The FTK core, made of 9U VME boards, performs the most demanding computational task. The Associative Memory Board Serial Link Processor (AMBSLP) and the Auxiliary card (AUX), plugged on the front and back sides of the same VME slot, constitute the Processing Unit (PU), which finds tracks using hits from 8 layers of the inner detector. The PU works in pipeline with the Second Stage Board (SSB), which finds 12-layer tracks by adding extra hits to the identified tracks. In the designed configuration, 16 PUs and 4 SSBs are installed in a VME crate. The high power-consumption of the AMBSLP, AUX and SSB (respectively 250 W, 70 W and 160 W per board) required the development of a custom cooling system. Even though the consumption expected for each VME crate of the FTK system is high compared to a common VME setup, the 8 FTK core crates will use ~ 50 kW, which is just a fraction of the power and the space needed for a CPU farm performing the same task. We report on the integration of 32 PUs and 8 SSBs inside the FTK system, on the infrastructures needed to run and cool them, and on the tests performed to verify the system processing rate and the temperature stability at a safe value.