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. 2016 Jan 6;9:484. doi: 10.3389/fnins.2015.00484

Table 2.

The energy scaling for all the operations is given.

Operation Analog energy scaling Digital energy scaling Repetitions per batch
MATRIX OPERATIONS
Multiplication: A(t)T × yk O(N × M) O(N3∕2 ×M3∕2) p
Multiplication: A(t) × xk O(N × M) O(N3∕2 ×M3∕2) p
Multiplication/Training: (ykA(t)xk)×sgn(xk)T O(N × M) O(N3∕2 × M3∕2) p
VECTOR OPERATIONS
Threshold: thresholdC (A(t)Tyk) O(N × 2b) O(N × b) p
Subtraction: ykA(t)xk O(M × 2b) O(M × b) p
Sign function: sgn(xk) O(N × 2b) O(N × b) P
COMMUNICATION
Vector: (ykA(t)xk) O(N × M) O(N1∕2 × M3∕2) P
Vector: sgn(xk)T O(M × N) O(N3∕2 × M1∕2) P
Matrix: g(t) O(N2 × M) O(N3∕2 × M3∕2) 1
SERIAL OPERATIONS
Read: g(t) O(N2 × M) O(N3∕2 × M3∕2) 1
Write: A(t+1)=A(t)ηpg(t)(t) O(N2 × M) O(N3∕2 × M3∕2) 1

We consider the finite precision case such that 2b < M.