On Friday 09 March 2007 11:07, pHilipp Zabel wrote: > On 3/8/07, Nils Faerber <[EMAIL PROTECTED]> wrote: > > Pierre Hébert schrieb: > > > It doesn't seem so bad : my [EMAIL PROTECTED] shows 199bogomips, so at > > > 200MHz 100bogomips seems correct (s3c2440 has the same cpu as s3c2410). > > > I don't know if the bogomips indication is a value in which we can > > > really trust, these little devices are really efficient even at > > > 100/200bogomips. > > > > The bogomips result is a little different depending on the core > > architecture. So for the Samsung CPU bogomips ~= 1/2 MHz. > > OK, good to know! > > A PXA270 I have on my desk has the ~ 1:1 bogomips to MHz mapping... > > I guess this depends on how many cycles the __delay(loops_per_jiffy) loop > > ENTRY(__delay) > subs r0, r0, 1 > bhi __delay > mov pc,lr > > takes on the given cpu. > On the S3C2440 subs takes 1S and bhi takes 2S+1N cycles. > Is information about the PXA27x instruction cycle times available > somewhere?
If you are interested in estimating cpu clock frequency, you can try a simple test program I have written some time ago: http://ufo2000.xcomufo.com/maemo/testfreq.c A few references related to arm cpu performance. Instruction timings and optimization guide for ARM9E: http://arm.com/pdfs/DDI0222B_9EJS_r1p2.pdf Instruction timings and optimization guide for ARM11 (used in OMAP2): http://arm.com/pdfs/DDI0360C_arm11mpcore_r0p3_trm.pdf Instruction timings and optimization guide for Intel XScale: http://download.intel.com/design/int...e/27347302.pdf Instruction timings and optimization guide for Cortex (used in OMAP3): http://arm.com/pdfs/DDI0337C_cortexm3_r1p0_trm.pdf Comparison of ARM7 and ARM9: http://arm.com/pdfs/comparison-arm7-arm9-v1.pdf Comparison of ARM9 and Cortex: http://arm.com/pdfs/13128.pdf _______________________________________________ OpenMoko community mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/community
