I have conducted the results on the coachbench benchmark. Each one performs repeated access to data items on varying vector lengths. Timings are taken for each vector length over a number of iterations. Computing the product of iterations and vector length gives us the total amount of data accessed in bytes. This total is then divided by the total time to compute a bandwidth figure. This figure is in megabytes per second. Here we define a Megabyte as being 10242 or 1048576 bytes. In addition to this figure, the average access time in nanoseconds per each data item is computed
and reported.
But I just got the result in the following form: why there is a sudden decrease in the time by increasing vector size.
output:
C Size Nanosec
256 11715.798191
336 11818.694309
424 11812.024314
512 11819.551479
.... ......
..... .....
4194309 9133.330071
I need the results in the following form. How I get this result.
The output looks like this:
Read Cache Test
C Size Nanosec MB/sec % Change
------- ------- ------- -------
4096 7.396 515.753 1.000
6144 7.594 502.350 1.027
8192 7.731 493.442 1.018
12288 17.578 217.015 2.274
Sorry mistakenly I have written coachbench.. The correct one is Cachebench Benchmark
C Size Nanosec
256 11715.798191
336 11818.694309
424 11812.024314
512 11819.551479
.... ......
..... .....
4194309 9133.330071
But I am confused in this, that if we increase the vector size then for writing or reading the data will be coming from the main memory because it will not be present in the cache then, in this case, the time should be increased. But I am confused that why it's decreasing when we increase the vector size.
Dear Sir, If I am wrong please do correct me.
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