From: "Phil Endecott" Subject: Re: Power measurements Date: Mon, 25 Jun 2007 10:10:51 +0100 Message-ID: <1182762651706@dmwebmail.belize.chezphil.org> References: <467F633B.3000909@interia.pl> Mime-Version: 1.0 Return-path: In-Reply-To: <467F633B.3000909@interia.pl> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: cpufreq-bounces@lists.linux.org.uk Errors-To: cpufreq-bounces+glkc-cpufreq=m.gmane.org+glkc-cpufreq=m.gmane.org@lists.linux.org.uk Content-Type: text/plain; format="flowed"; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: cpufreq@lists.linux.org.uk Rafa=C2=B3 Bilski wrote: >>> % dmesg | grep eps=20 >>=20 >> Thanks, yes, I found this after I posted my last message. Apparently it >> should use 860 mV at 1.2 GHz and 844 mV at 400 MHz. >>=20 > Most C7-Eden CPU's have same voltage on=20 > high and low frequency. Looks like Your's has different voltages. If=20 > You don't see 844mV at 400MHz then probably VID pins aren't connected=20 > to VRM on motherboard. > Mode MHz Voltage (mV) Power (W) > P0 1200 860 7 > P1 400 844 3 May I ask where these numbers come from? >> My aim is to make this machine as >> power-efficient as possible, which I've achieved mainly by working on >> the PSU (the first one I had was < 40% efficient, now I'm up to about >> 70%), and by using a solid-state disk. It's getting increasingly >> difficult to find things to improve! > Newer PSU's should have 80%-85% efficiency. But 70% isn't that bad. Don't believe that until you've measured it. The numbers that they advertise are always in the best conditions,=20 which is normally maximum load. If you operate it in different=20 conditions the performance will be worse. For example, the power=20 supply that is giving me 70% efficiency advertises itself as having=20 >80% efficiciency. > You should probably poke some registers in northbridge. I don't=20 > know much about newer VIA chipsets, but older (CLE266) had many bits=20 > which could improve power savings - dynamic clock stop to different=20 > chipset components, ACPI C3 can put memory to sleep and so on.=20 > Unfortunatly these bits are disabled by default and are never touched=20 > by BIOS. Is there any documentation available for any of this? Hmmm, I really should learn something about ACPI. > Btw. Can You benchmark Your's C7 for me? I would like to compare it to=20 > my P4-M which is eating much more power. I'm not sure how much exacly=20 > because I had to change FSB frequency, but something about 25W. > Maybe "nbench"? Here is nbench for my Jetway J7F2 with VIA C7 @ 1.2G with the=20 'ondemand' governor: BYTEmark* Native Mode Benchmark ver. 2 (10/95) Index-split by Andrew D. Balsa (11/97) Linux/Unix* port by Uwe F. Mayer (12/96,11/97) TEST : Iterations/sec. : Old Index : New Index : : Pentium 90* : AMD K6/233* --------------------:------------------:-------------:------------ NUMERIC SORT : 354.96 : 9.10 : 2.99 STRING SORT : 39.736 : 17.76 : 2.75 BITFIELD : 1.1172e+08 : 19.16 : 4.00 FP EMULATION : 46.664 : 22.39 : 5.17 FOURIER : 2729.8 : 3.10 : 1.74 ASSIGNMENT : 8.4321 : 32.09 : 8.32 IDEA : 1042.5 : 15.94 : 4.73 HUFFMAN : 525.7 : 14.58 : 4.66 NEURAL NET : 4.7302 : 7.60 : 3.20 LU DECOMPOSITION : 298.8 : 15.48 : 11.18 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3DORIGINAL BYTEMARK RESULTS=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D INTEGER INDEX : 17.572 FLOATING-POINT INDEX: 7.148 Baseline (MSDOS*) : Pentium* 90, 256 KB L2-cache, Watcom* compiler 10.0 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3DLINUX DATA BELOW=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D CPU : CentaurHauls VIA Esther processor 1200MHz 1200MHz L2 Cache : 128 KB OS : Linux 2.6.21-1-686 C compiler : gcc version 4.1.3 20070601 (prerelease) (Debian 4.1.2= -12) libc : libc-2.5.so MEMORY INDEX : 4.507 INTEGER INDEX : 4.295 FLOATING-POINT INDEX: 3.964 Baseline (LINUX) : AMD K6/233*, 512 KB L2-cache, gcc 2.7.2.3, libc-5.4.38 * Trademarks are property of their respective holder. The results for 'performance' are INTEGER INDEX : 17.530 FLOATING-POINT INDEX: 7.157 i.e. essentially the same. For 'powersave' (400 MHz) the results are: INTEGER INDEX : 5.828 FLOATING-POINT INDEX: 2.379 which is almost exactly 1/3 of the speed. For comparison a 1 GHz C3 gives: INTEGER INDEX : 13.785 FLOATING-POINT INDEX: 5.219 Comparing the C3 and the C7, the C7 gives 14.61 integer-index per GHz=20 and the C3 gives 13.79 integer-index per GHz, so the C7 is 6% faster=20 per GHz. For floating point it's 14% faster per GHz. (I think my C3=20 probably has slower RAM, but I'm not sure about that.) How does this compare with your Intel chip? Regards, Phil.