On Wednesday 22 October 2003 02:21, Bob Hillegas wrote: > Assuming I'm installing a software raid, is there any consensus on which > controller is best suited to that duty? > > Best scsi and best IDE. What you first have to take in mind is that the PCI bus can be a bottleneck. The 32bit/33Mhz PCI bus can manage 133MB/s (without overhead). If you e.g. connect two fast IDE-Harddisks, like the WD-Raptor (which has max. ~ 60MB/s read performance) and do a RAID0, then you would theoretically achieve 120MB/s - if you pipe this out to a 100MBit NW, you get around 130MB/s. I'd say this is already too much for the PCI bus as there is around 30% overhead included. There are two workarounds to this problem: - Use 64-bit PCI Hardware (expensive) - Use onboard Controller that are directly connected to the Southbridge - but notice: Not all onboard controllers are directly connected, many are simply connected to the 32-bit/33Mhz PCI bus. Moreover the controllers vary with the CPU Load. I only know that e.g. the SATA RAID controller from Silcon Image (sil3112A) has a low CPU load but AFAIK the sil3112 is a simple PCI device. An example of an IDE-Onboard controller that is connected to the Southbridge is the Intel ICH5(R) southbridge that is implemented in the 875/865 intel chipsets. Moreover you have to find out if these IC's are properly supported with Linux. Sorry - with SCSI I have not much knowledge. Best Regards, Hermann -- x1@aon.at GPG key ID: 299893C7 (on keyservers) FP: 0124 2584 8809 EF2A DBF9 4902 64B4 D16B 2998 93C7 - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
