openssl – AMD vs Intel
The openssl Phoronix benchmark is interesting because the IPC on Intel Haswell system (1.66) is considerably higher than the IPC on AMD Ryzen (1.12). In this post, I’ll explore to look for causes.
Continue reading →Tag Archives: analysis technique
topdown equivalent metrics for AMD Zen?
Intel processors provide a useful set of performance counters for doing topdown analysis, particularly at the first topdown level. This first level asks questions in the following hierarchy: Is a Uop dispatched? If yes, is it retired? If yes –> … Continue reading →
Investigating Intel performance counters for backend memory costing…
I’ve implemented the first level for topdown performance counter analysis and also done an initial analysis of ~15 workloads from recent Phoronix article. A logical next step is to expand the “backend bound” category to first separate CPU-bound vs. memory-bound … Continue reading →
Off CPU analysis, getrusage, wait4 and related techniques…
As I looked to analyze x264, I saw that the On CPU metric was considerably less than other benchmarks like openssl or c-ray that are On CPU almost 100% of the time. I also noticed that my Ryzen 1700 box … Continue reading →
Top down performance counter analysis (part 2) – wspy
As described in top down performance counter analysis part 1, top down analysis is an approach that uses key performance counters to characterize an application and then successively drills down with further refinement. On Intel x86 processors, this first level … Continue reading →
Top down performance counter analysis (part 1) – likwid & perf
In this posting I summarize top-down performance counter analysis to evaluate workloads and show how this can be measured on Haswell using likwid-perfctr and perf. In part 2 to follow, I’ll describe how top down metrics have been added to … Continue reading →