15-347 Spring '98
Performance Measurements on the Alpha 21164s
The machines we're using for class have the following characteristics:
- Based on DEC Alpha 21164 CPU.
- Our clock frequency program measures them at 433 MHz
- The timer interval (delta) is .976 milliseconds (very short!)
In Lecture 8, we presented results on matrix multiplication on a
DECStations & a Sparc20. The following reports the results for an Alpha.
- I had to crank the matrix sizes up to 500 X 500 to get really bad
(out of cache) performance.
- The numbers are about an order of
magnitude better than the SPARC20.
The following shows the unblocked
- The actual block matrix code
shown in the notes didn't run very well. I had to tweak the loops to
get rid of the "max" operation. As an example, the code for the bijk is available online.
The following is the resulting performance: