After working mostly with different ARM processors in the 200...400 MHz range in lots of Embedded Linux projects over the last years, we have seen an interesting development in the market recently:

• ARM cpus, having been known for their low power consumption, are becoming faster and faster (example: OMAP3, Beagleboard, MX51/MX53).
• x86, having been known for its high computing performance, is becoming more and more SoC-like, power friendly and slower.

If you read the marketing stuff from the chip manufacturers, it sounds like if ARM is the next x86 (in terms of performance) and x86 is the next ARM (in terms of power consumption). But where do we stand today? How fast are modern ARM derivates?

The Pengutronix Kernel team wanted to know, and so we measured, in order to get some real numbers. Here are the results, and they turn up some interesting questions. Don't take the "observations" below too scientifically - I try to sum up the results in short claims.

As ARM is explicitly a low power architecture, it would have been interesting to measure some "performance vs. power consumption" data. However, as we have done our experiments on board level products, this couldn't be done. Some manufacturers tend to put more peripheral chips on their modules than others, so we would have only measured the effects of the board BoMs.

root@target:~ lat_ops 2>&1

grep "^float mul:" | cut -f3 -d" "

root@target:~ list="rd wr rdwr cp fwr frd bzero bcopy"; \
for i in $list; \
do echo -en "$i\t";  done; \
echo; \
for i in $list; \
do res=$(bw_mem 33554432 $i 2>&1 | awk "{print \$2}"); \
echo -en "$res\t"; done; \
echo MB/Sec

awk "/rd\twr\trdwr\tcp\tfwr\tfrd\tbzero\tbcopy/ { getline; print \$3 }"