Wilco (Wilco.Dijkstra@ntlworld.com) on 1/12/11 wrote:
---------------------------
[snip]
>Well, obviously any benchmark that shows Cortex-A9 to be faster than Atom is not
>going to be good enough, is it? But why don't you Google for A9 benchmarks yourself? I found this in 30 seconds:
>
>http://www.open-chess.org/viewtopic.php?f=24&t=775&start=10
>
>Palm Pre 500mhz (Webos1.4.5): ~8.000 NPS
>APAD Rockchip 600mhz (android1.5): ~10.000 NPS
>Palm Pre oc. 800mhz (Webos1.4.5): ~13.000 NPS
>ZT-180 10,2" Pad : ~15.345 NPS
>Palm Pre oc. 1Ghz (Webos1.4.5): ~16.000 NPS
>Archos 101 (android 2.1): ~78.300 NPS
>Iphone4 800 Mhz (IOS): ~80.000 NPS
>HTC HD2 with 1Ghz (android2.2): ~100.000 NPS
>Samsung Galaxy Tab: ~108,500 NPS
>Advent vega tegra2 1Ghz (android2.2): ~131.700 NPS
>Dell Streak (Steves 1.4.5, OC 1150Mhz): ~133.000 NPS.
>Netbook Intel Atom N270 1.6 Ghz (Windows XP): ~143.000 NPS
>Advent vega tegra2 1Ghz 2cores (android2.2): ~220.500 NPS
>
>Laptop T7600 2.2Ghz 1 core, (windows vista64): 1.000.000 NPS

Those numbers seem to reinforce Linus Torvalds' point.
The highest performing (single core) ARM is noticeably
slower than a rather ordinary Atom and an Atom is about
a decimal order of magnitude slower than a typical desktop
x86 processor.

Here are some CoreMark scores:

NVIDIA Tegra 250 (gcc 4.4.5), 2646.38 CoreMark at 1 GHz
Intel Core i5-650 (gcc 4.4.5), 10379.90 CoreMark at 3.2 GHz
Intel Atom N270 (gcc 4.4.1) 2 threads, 4567.25 CoreMark at 1.6 GHz
Intel Celeron (gcc 4.1.2), 2737.85 CoreMark at 1.2 GHz


I do not know the effectiveness of Atom's SMT for CoreMark.
It is probably greater than on realistic workloads. (One
might argue that gcc's x86 target is more mature.) Tegra
is about 4 times slower than Core i5 (a typical desktop
x86) and just about even with an _old_ x86. (One of the
problems with the low-end CPUs--Atom or Cortex A series--is
the poor memory systems attached to them.) I _think_ that
Tegra uses an A8 (or derived core), so an A9 might add 25%
to that score.

Performance per MHz or per Watt are not valid metrics
when one is concerned with maximum performance. (Even for
a laptop--given the power consumption of current displays--
the CPU does not gain much from being extremely power
efficient. ARM might be able to undercut Oracle's T-series
servers [given a larger address space] in the near future,
but no announced ARM is close to an Intel x86 server chip
in performance.)