|HP PA 7100||3||0.80||$1300||1.0||196||66||27%||$73|
IC cost = ( Die cost + Testing cost + Packaging cost ) / Final test yield
Packaging Cost: depends on pins, heat dissipation, etc...
|HP PA 7100||$73||504||PGA||$35||$16||$124|
or CPU execution time = (CPU clock cycles for pgm) / (clock rate)
CPU clock cycles for pgm = (Instructions for pgm) * (avg. clock cycles per instr.)
or CPI = (CPU clock cycles for pgm) / (Instructions for pgm)
CPI tells us something about the Instruction Set Architecture, the Implementation
of that architecture, and the program measured
MFLOP/S = Floating point Operations / (Time * 10^6)
This is very machine dependent and FP operations are often not where
time is spent
Benchmarks should represent large class of important programs
Improving benchmark performance should help many programs
Uses a standard list of programs, some real programs, includes OS calls, some I/O.
One program: 99% of time in single line of code
New front-end compiler could improve dramatically. Compare these two results on the same machine but using different compilers.
Add SPECbase: one flag setting for integer programs & one for FP
Harmonic mean (or weighted harmonic mean) of rates (e.g., MFLOPS):
n/SUM(1/Ri) or n/SUM(Wi/Ri)
Normalized execution time is handy for scaling performance
(e.g., time on reference machine ÷ time on measured machine)
But do not take the arithmetic mean of normalized execution time, use the geometric_ mean (prod(Ri)^1/n) because this does not depend on which is the reference machine.
Unfortunately, geometric mean rewards all improvements equally:
program A going from 2 seconds to 1 second as important as
program B going from 2000 seconds to 1000 seconds
ExTime w/o E Performance w/ E Speedup(E) = ------------ = ----------------- ExTime w/ E Performance w/o ESuppose that enhancement E accelerates a fraction F of the task by a factor S and the remainder of the task is unaffected then,
ExTime(with E) = ((1-F) + F/S) * ExTime(without E)
Speedup(with E) = ExTime(without E) /
((1-F) + F/S) * ExTime(without E)