May 26, 201214 yr So the motherboard I am using has one pcie x16, one pcie x1 (which my intel nic is using) and 2 pci slots. I intend on putting the br10i in the x16 slot for 8 additional sata drives (the motherboard has 4 ports) -- so that gives me a total of 12 ports. I will have 3 x ss-500 (5x3 trays) in my prominent 9 tower, for 15 drive bays. So I will have 3 drive bays free. I was wondering if it makes sense to get 2 x pci 2 port sata controllers to handle the extra 3 bays. (there will be one unused). The motherboard supports pci 2.2 which is the 66mhz frequency. Shouldn't a pci 2.2 two port sata card be able to handle reads of 100MB/s from two drives on the same controller? Using a pci 2.2 card with two drives on the controller: would this be a bottleneck for parity checks?
May 27, 201214 yr The problem is, there are barely any standard PCI cards that use the 66mhz "extra feature" of PCI-X slots, or in standard PCI slots. But you also have to remember that alot of devices can be connected to the PCI slots. I'm not sure how new your board is, but it can be possible that the Audio codec, IDE & Floppy, Serial & Parallel ports are all connected to the one PCI Bus. Maybe also Ethernet. So if you have PCI Gigabit Ethernet and a capable harddisk on a SATA PCI controller, they have to share the 133MB/s bandwidth already when transferring data over the network. I use this only with slow or not so important harddisks...
May 27, 201214 yr Yes, using standard PCI slots to attach more than 1 drive will be a bottleneck for the system in the following cases: multiple writes at the same time, multiple reads at the same time, parity checks, failed drive simulations, failed drive recovery. As already explained, none of the non-server motherboards will support anything other than the bog standard 33Mhz PCI bus which limits you to a MAXIMUM 133 MB/s. Once you put two drives on there then the theoretical fastest you can ever get is 66MB/s in the listed situations above. In reality you will get less than that due to various overhead factors. It's best to completely ignore the PCI bus for anything more than 1 drive.
May 28, 201214 yr Author ok so 1 hard drive per pci slot (i have two of those slots).. that gives me 2 + 4 (motherboard) + 8 (br10i) = 14.. darn 1 short of the 15 bays 3 x ss-500 offers me, lol.
May 28, 201214 yr What you don't understand is, PCI is ONE BUS. ALL the devices that are on PCI have to share the same 133MB/s bandwidth. The only machines with real independent PCI(-X) slots was some SUN server...
May 28, 201214 yr Author ok so it sounds like i should free up my pci-e x1 slot by removing the gigabit nic and buy a PCI gigabit nic instead. Then buy a pci-e x1 2 porta sata controller, which will get me about 90MB/s to each of the drives, since I have a pci-e 1.1 motherboard.
May 28, 201214 yr Author Actually now I am thinking about just replacing the motherboard on that machine with my gigabyte p35-ds3l motherbaord which has three pci-e x1 slots. IT's also pci-e generation 2 (2.1 i think). Hopefully the br10i would work in one of these two motherboards!
May 28, 201214 yr Actually now I am thinking about just replacing the motherboard on that machine with my gigabyte p35-ds3l motherbaord which has three pci-e x1 slots. IT's also pci-e generation 2 (2.1 i think). Unfortunately, no. I have a p35-ds3r (and just checked the spec for the p35-ds3l rev2.0). No PCI-E Gen2 for us.
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