A couple of RAID questions

[kaltag]

Good afternoon. First off, I'm planning on upgrading my file server soon to SATA and need some advice/questions answered.

1. I've searched the forum but haven't found any hard numbers about the cpu usage of a software RAID 5 setup. This is just a personal file server so ultra high-end performance is not a big deal. I was curious what others who are running a software RAID 5 get for CPU usage under write condiitons?

2. I have a 600mhz Via C3 micro ITX board I'm tempted to use since it's not doing anything else right now and then adding an 8 port SATA controller card to it. I'm curious about the cpu usage because obviously this isn't a real powerful board. All it would have to do is basically run samba and FTP though.

3. The other option I'm looking at is just getting a newer board/proc (Athlon 64 3000+) with 8 SATA ports onboard and Gb LAN if possible, prefferably in micro ATX format to save some space. This option is a bit more expensive though than what I really want to spend but I can pop for it if need be.

4. Are there any recommendations anyone could make as to a model of motherboard or SATA controller card to suit my purposes?

Any and all information would be greatly appreciated
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[simeli]

I am kinda in the same boat - personal file server http://osiris.simeli.net. I have a Gigabyte K8N Ultra SLI board that has 8 SATA ports onboard plus dual Gb Ethernet. it uses a passively cooled Nforce chip, so the noisy small fan from that is ruled out. the "problem" with that board and most others having additional SATA ports is that the additional ones are sitting on the PCI bus. if using a software raid solution, lots of redundant data has to be transferred over the PCI bus slowing down the system. I have just moved away from a Sun Netra box to my new server and have yet to add some more disks and a raid setup.

I would say that a 600Mhz VIA is probably not going to be great for a raid 5 setup although i don't have any numbers to prove that. I'd guess that you'd probably get about 7MB writes but not much more having a raid 5 on the PCI bus. Reads should be fairly fast, certainly enough for a 100Mb network. The VIA ethernet chips are like the Realteks not really famous for great performance and also put quite some stress on the CPU. I don't recall where I read the benchmarks for that but Google should help.

The new Nvidia chipset with integrated graphics is available in mATX factors. See Gigabyte or Asus websites. If power consumption and noise is an issue for you I'd recommend looking into a Pentium M based solution like mine (MSI 915GM Speedster). you can find an overview of boards on my website here http://osiris.simeli.net/server. The DFI board has a PCI-X slot which would definitely be good for adding an additional SATA controller. Or if you can afford it use an Areca PCIe controller. LSI Logic Megaraid 150-4 and 150-6 are also available at pretty low prices, are real hardware raid solutions and performance is still quite high. They also work in legacy PCI slots i.e. 32bit. Personally I am looking at adding such a controller to my setup. Softraid of course has the advantage that the raid controller as a single point of failure does not exist anymore. If you do backups that is of no concern for a home server however.

Edit: here are some bechs on a pII 400Mhz that would probably compare to the power of a 600Mhz C3: https://forums.gentoo.org/viewtopic-t-378535-highlight-raid+5+performance.html