> I have been using an older 64bit system, socket 754 for a while now. It > has > the old PCI bus 33Mhz. I have two low cost (no HW RAID) PCI SATA I cards > each with 4 ports to give me an eight disk RAID 6. I also have a Gig NIC, > on the PCI bus. I have Gig switches with clients connecting to it at Gig > speed. > > As many know you get a peak transfer rate of 133 MB/s or 1064Mb/s from > that > PCI bus http://en.wikipedia.org/wiki/Peripheral_Component_Interconnect > > The transfer rate is not bad across the network but my bottle neck it the > PCI bus. I have been shopping around for new MB and PCI-express cards. I > have been using mdadm for a long time and would like to stay with it. I > am > having trouble finding an eight port PCI-express card that does not have > all > the fancy HW RAID which jacks up the cost. I am now considering using a > MB > with eight SATA II slots onboard. GIGABYTE GA-M59SLI-S5 Socket AM2 NVIDIA > nForce 590 SLI MCP ATX. > > What are other users of mdadm using with the PCI-express cards, most cost > effective solution? > > I agree that SATA drives on PCI-E cards are as much bang-for-buck as is available right now. On the newer platforms, each PCI-E slot, the onboard RAID controller(s), and the 32-bit PCI bus all have discrete paths to the chip. Play with the thing to see how many disks you can put on a controller without a slowdown. Don't assume the controller isn't oversold on bandwidth (I was only able to use three out of four CK804 ports on a GA-K8NE without saturating it; two out of four slots on a PCI Sil3114). Combining the bandwidth of the onboard RAID controller, two SATA slots, and one PCI controller card, sustained reads reach 450MB/s (across 7 disks, RAID-0) with an $80 board, and three $20 controller cards. - 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
