On Wed, Jul 02, 2008 at 05:56:03PM +0200, Keld Jørn Simonsen wrote: > I should have done something else this afternoon, but anyway, I was > inspired to write up this text for the wiki. Comments welcome. > > Keld > [...] > Many SATA controllers are on-board and do not use the PCI bus. Anyway > bandwidth is limited, but it is probably different from motherboard to > motherboard. On board disk controllers most likely have a bigger > bandwidth than IO controllers on a 32-bit PCI 33 MHz, 64-bit PCI 66 MHz, > or PCI-E x1 bus. Sorry to ask... are you sure the on-board controllers are *not* on the PCI bus? They are not physically over the PCI bus, but still connected via the same upstream-controller, I think, and still limited. I'm not familiar in this area, but the mainboard diagrams (the ones with pretty pictures, not electric ones) show that the on-board controllers 'hang' on the same PCI or PCI-E bus as the physical slots. > RAM sppec may be a bottleneck. Using 32 bit RAM - or using a 32 bit > operating system may double time spent reading and writing RAM. > > CPU usage may be a bottleneck, also combined with slow RAM or only using > RAM in 32-bit mode. Sorry, what is "32 bit RAM"? I never heard of this. Do you mean dual-channel versus single-channel? thanks! iustin -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
