Hi,
We found the following document on Cortex-A9 performance.
List of ARM microarchitectures - Wikipedia, the free encyclopedia
Which claims 2.5 DMIPS/MHz per core for Cortex-A9 2GHz@2 core. However, our Dhrystone result on Cortex-A9 1.2GHz@2 core only showed roughly 1 DMIPS/MHz per core.
We downloaded the Dhrystone benchmark from the following link and cross-compiled it with gcc version 4.5.2.
dhrystone 2.1 - Download, Browsing & More | Fossies Archive
We realize that Dhrystone measurements will vary due to differences in compilers and OS. And I would like to know whether our result is reasonable or not?
Best,
Ying
No I don't think that result is reasonable
I think the test should fit in the cache so the memory speed shouldn't matter.
I'm sorry this is the is it plugged in question but just to be certain.
What flags did you supply to gcc, did you specify gcc -O3 -Ofast -mcpu=cortex-a9 -mfpu=neon-f16 –DNDEBUG (the fpu option shouldn't really matter but just to have a standard set, only the -O3 should have a large effect)
How are you certain it was running at 1.2GHz rather than thermally throttled like many smartphones do after they done some hard work for a while?
Thank you for all your suggestions. Finally I found that our processor is actually set to run at 800MHz. Therefore, it would be reasonable to have 2.5 x (800/1200) = 1.66 DMIPS/MHz/core. Although I got 1.37 DMIPS/MHz/core by gcc 4.5, I can get 1.6 DMIPS/MHz/core by gcc 4.9, which is close to the official value.
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