Hey people. I`m in the process of building a file server but have come up against a question I need answered before going to far. I am using a dual p3 pc for the file server, 2 sata raid cards will be plugged into the board as well as a network card. my question is this. Will all that load cause any problems with data transfer? I`ll be using it mostly as a file store for my htpc
If it's normal 32-bit 33MHz PCI, then yes it will... but what transfer speeds do need? If you're only using it with one other computer it still should be fine. If each SATA card has four HDDs attached, thats a max. of roughly 4x70Mbit per card, so 560Mbits from them... while PCI only supports 250Mbit/s or 127Mbits/s per card, I'm not sure. Assuming you're allowed to use more than 250Mbit/s per card, that leaves ~550Mbits for you LAN card... but even video streaming doesn't use that much bandwidth, so it should be fine. ch424
Lets try this again shall we? The PCI bus is limited to 133 MBytes sec theoretically, but youll never get more than about 120MB through it (so lets say 1 gbit) One card can steal all the bandwith if it needs it even if youre using quite old drives, 8 of them will easily max that straight out, especially if youre only having a single array (depends on the cards youre getting, but you may not be able to have a single array from 2 cards) now lets pretend you want a gigabit network card, the PCI bus limits this as well, as you wont get more thn 50MB/sec transfer out of it if its even the only one on the bus, let alone with 8 drives So you can do the maths there, a network card that is capable of 120MB/sec and an array/arrays capable of a combined max of around 400MB/sec on a bus that has a max of 120MB/sec The PCI bus would be a major bottleneck in the system, however it would still work. I'd reccommend looking into a board with PCI-X - a 64/133 slot gives you 8x the bandwidth of standard 32/33 PCI
The problem is I have the dual p3 sitting doing nothing. IT`s gonna be the htpc pulling off it and maybe 2 computers pulling the odd file off it. If I could find a dual p3 board that has pcix slot for cheap enought Id do that.
well ebay and here are your best bets, if you can find a board, it wont cost a great deal, its just the matter of fining a pci-x one At the end of the day, it will still work at a reduced with 32/33 pci, but it wont be ideal. It may be worth saving some money and just going for single drives over an array, unless youre going for an array for the redundancy rather than the speed
Im not actually running it in raid though. I will be running an lvm on it. I dont care so much about the out and out speed its more about having one large drive for storage.
Master_tad is almost right, there is bus arbitration to help prevent a card from stealing all the bandwidth, and delayed transactions can help too. Still, assuming a 60 MBPs, 3 drives will mav out the bus. However, if you look at the data rates needed for streaming video, you should be OK because the actual data rate required should be much lower. IF yo were intending to build a server to work a database taking info from, say, an internet store front all day, then I'd be concerned. But also consider all the 'high performance' SCSI based arrays running off of a 64 bit PCI slot along with all the other stuff connected to the bus. Also keep in mind that it doesn't need to be a card to be on the bus. Also, there is the possibility of a second PCI host to split things up and divide the load. If there are 64 bit PCI slots, then it is a little more likly, though you may need to check the PnP section of your BIOS for PCI IRQ routing info, that might help you figure it out. In the end, I wouldn't let it keep you up at night. If you already have all the parts, go ahead and throw it all together and see if it is sufficent.
