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Spreadsheet-based Energy Accounting

Knowing the average number of operations per second on a unit is generally all that is needed to work out its average energy, once the joules per operation are known.

The Xilinx Xpower 28 nm Zynq spreadsheet models about 415 pJ per ARM clock cycle and 23 pJ per DSP multiply. BRAM reads of RAMB18x2 (36 Kbit) units take 8.5 pJ and writes about 10 percent less.

The formula earlier for 45nm, 5.0 + 1.2e-4 / 8.0 *m_bits gives 5.5 pJ but twice as much for a write.


44: (C) 2008-17, DJ Greaves, University of Cambridge, Computer Laboratory.