Intel TurboBoost in practice

[Norikatsu Shigemura]

Hi mav.

On Sat, 24 Jul 2010 16:53:10 +0300
Alexander Motin <mav at freebsd.org> wrote:
> PS: In this case benefit is small, but it is the least that can be
> achieved, depending on CPU model. Some models allow frequency to be
> risen by up to 6 steps (+798MHz).

	I tested on Core i7 640UM (Arrandale 1.2GHz -> 2.26GHz) with
	openssl speed (w/o aesni(4)) and
	/usr/src/tools/tools/crypto/cryptotest.c (w/ aesni(4)).

	http://people.freebsd.org/~nork/aesni/aes128cbc-noaesni.pdf [1]
	http://people.freebsd.org/~nork/aesni/aes128cbc-aesni.pdf [2]

[1] $ /usr/bin/cpuset -l$i /usr/bin/openssl speed -elapsed -mr -multi $n aes128-cbc
 $i = 0 1 2 3 0,1 0,2 0,3 1,2 1,3 2,3 0,1,2 0,1,3 0,2,3 1,2,3 0,1,2,3
 $n = numbers of core, $((`echo $i | wc -c`/2))

[2] $ /usr/bin/cpuset -l$i ./cryptotest -t $n -z 50000 8192
 $i = 0 1 2 3 0,1 0,2 0,3 1,2 1,3 2,3 0,1,2 0,1,3 0,2,3 1,2,3 0,1,2,3
 $n = numbers of core, $((`echo $i | wc -c`/2))

	In my environment, according to aes128cbc-noaesni.pdf, at least,
	30% performace up by Turbo Boost (I think).

	And according to aes128cbc-aesni.pdf, at least, 100% performance
	up by Turbo Boost (I think).

	And I understand reducing single thread performance by Hyper
	Threading:-).

-- 
Norikatsu Shigemura <nork at FreeBSD.org>