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 <[EMAIL PROTECTED]> 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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