Date: Fri, 26 Nov 2004 13:24:14 +0900 From: Rob <spamrefuse@yahoo.com> To: freebsd-stable@freebsd.org Subject: Re: make -j$n buildworld : use of -j investigated Message-ID: <41A6AFEE.8030001@yahoo.com> In-Reply-To: <20041126025251.GA94802@xor.obsecurity.org> References: <opsh0jp9ge8527sy@smtp.local> <3282.1101377849@thrush.ravenbrook.com> <41A698A5.6010601@yahoo.com> <20041126025251.GA94802@xor.obsecurity.org>
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Kris Kennaway wrote: > On Fri, Nov 26, 2004 at 11:44:53AM +0900, Rob wrote: > >>Nick Barnes wrote: >> >>>On Thu, 25 Nov 2004 16:19:02 +0900, Rob <spamrefuse@yahoo.com> wrote: >>> >>> >>> >>>>> time(minutes) * speed(MHz) * nproc / 1000 MHz >>> >>> >>>Looking at your examples, it seems you divide by 1e5, not by 1000. >> >>Sorry, yes you're right. >> >> >>>In other words, buildworld is CPU bound and takes about 6e12 clock >>>cycles. Use -j<nproc>. >> >>My main point is: when using "-j<nproc>", I am able to predict how long >>the buildworld takes on a range of 'mainstream' systems like the ones I >>have (pentium-II to pentium-IV and dual-pentium-III): >> >> time(minutes) = 1e5 / ( speed(MHz) * nproc ) >> >>P-II 333 MHz : 300 min. >>P-III 700 MHz : 142 min. >>P-III 2x800 MHz : 62 min. >>P-IV 2000 MHz : 50 min. >> >>Within a few minutes, all these times are correct. >> >>I still have to test my P-I/150 MHz also running 5.3, and verify >>that buildworld will take approx. 670 min. > > > Of course, there are other factors that you don't consider that have a > huge impact on buildworld time, in particular disk performance. The formula then only applies to following disk configs (mainly UDMA33 and UDMA100): P-I (150): pcib0: <Host to PCI bridge> pcibus 0 on motherboard pci0: <PCI bus> on pcib0 atapci0: <Intel PIIX3 WDMA2 controller> port 0x9000-0x900f,0x376,0x170-0x177,0x3f6,0x1f0-0x1f7 at device 7.1 on pci0 ata0: channel #0 on atapci0 ad0: 2445MB <QUANTUM FIREBALL EL2.5A/A08.1100> [5300/15/63] at ata0-master WDMA2 P-II (333): pcib0: <Intel 82443LX (440 LX) host to PCI bridge> pcibus 0 on motherboard pci0: <PCI bus> on pcib0 atapci0: <Intel PIIX4 UDMA33 controller> port 0xf000-0xf00f,0x376,0x170-0x177,0x3f6,0x1f0-0x1f7 at device 7.1 on pci0 ata0: channel #0 on atapci0 ad0: 3079MB <QUANTUM FIREBALL EX3.2A/A0A.0D00> [6256/16/63] at ata0-master UDMA33 P-III (700): pcib0: <Host to PCI bridge> pcibus 0 on motherboard pci0: <PCI bus> on pcib0 atapci0: <VIA 82C596B UDMA66 controller> port 0xe000-0xe00f,0x376,0x170-0x177,0x3f6,0x1f0-0x1f7 at device 7.1 on pci0 ata0: channel #0 on atapci0 ad0: 6149MB <QUANTUM FIREBALL EX6.4A/A0A.0D00> [13328/15/63] at ata0-master UDMA33 P-III (2x800): pcib0: <Intel 82443BX (440 BX) host to PCI bridge> pcibus 0 on motherboard pci0: <PCI bus> on pcib0 atapci0: <Intel PIIX4 UDMA33 controller> port 0xb800-0xb80f,0x376,0x170-0x177,0x3f6,0x1f0-0x1f7 at device 4.1 on pci0 ata0: channel #0 on atapci0 ad0: 43979MB <IBM-DTLA-307045/TX6OA50C> [89355/16/63] at ata0-master UDMA33 P-IV (2000): pcib0: <Host to PCI bridge> pcibus 0 on motherboard pci0: <PCI bus> on pcib0 atapci0: <Intel ICH2 UDMA100 controller> port 0xa800-0xa80f,0x376,0x170-0x177,0x3f6,0x1f0-0x1f7 at device 31.1 on pci0 ata0: channel #0 on atapci0 ad0: 152627MB <WDC WD1600JB-00FUA0/15.05R15> [310101/16/63] at ata0-master UDMA100 Regards, Rob.
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