True RAID on an old machine

P

Panamajack1

n00b
Joined
Jun 19, 2009
Messages
3
Hello all,
I have an old, old machine that I've been using as an NAS in non RAID for about 8 years now and was wondering if I were to buy a True RAID controller card with it's own processor does this processor offload the work from the main CPU and if it does am I limited by the PCI bus bandwidth? I'm thinking about setting it up as either RAID 0 or RAID 5. This would be my first RAID setup so any other help is welcome too.
 
Yes a true hardware RAID card will perform parity calculations without involving the system cpu, but if you get a PCI RAID card you will be limited by the PCI bus. Theoretical 133MB/s.....I actually hit the wall at about 89 by sticking a PCI-X SATA raid card in a 32-bit PCI slot. If you want any kind of performance you'll have to get something better than PCI.
 
Thanks that was what I was wanting to know. I wasn't sure how the controller cards worked. Their selling 32 bit cards claiming 600 mb/s but that must be for servers able to quad pump the bus or something. The machine I have is capable of and delivering udma 2 but the hard drive which is a lot newer is capable of UDMA 5. I was thinking of putting a Gigabit card in it, a couple more hard drives, and the True RAID controller but with what your saying I could put a non RAID controller in it and a Gigabit card and do just as well.
 
For the cost of all that stuff you could probably upgrade the board, cpu and RAM, and be much better off. You can get a newer celeron and a board with PCIe, faster IDE, and SATA ports for under $100....and it will probably have on board raid for the sata ports, and on board gigabit ethernet.IMO the new core architecture celerons are excellent for the price and would run well as a home file server.
 
I already have everything on hand except the non RAID controller and I've found some of the cheap ones that will handle UDMA 5 for about $15. I bought a whole mess of Realtek gigabit cards awhile back at less than $8 each. The controller doesn't have to be bootable and if the UDMA part is working right there shouldn't be much added load to the processor during transfers.
I run this machine headless via a remote desktop using TightVNC. I use this machine to download torrents and other files, as a music jukebox, and an in house file server. I was asking about the True RAID setup hoping to get better bandwidth than PCI is capable of through RAID 0
This was only the first part of a two part question anyway the next part was going to be about how to use the higher bandwidths with the limits of the gigabit cards themselves. Even in full duplex from what I understand you're still limited to around 250 MB/s. Infiniband or 10 gbase technology is still too expensive, around $350 per card (not to mention the cables) and if I go with the PCIe technology I would want to put it to work, so there's really no reason to upgrade the board right now but hey, if anyone knows how to get some real performance out of a remote server without costing an arm and a leg I'm definately open for suggestions.
 
Last edited:
I ran my Cheetahs for a short time on an Adaptec 29160 on 32 bit PCI, and it would top out at a consistent 108MB a second, on an ASUS M2N-E (NForce 570 Ultra). It will depend on the chipsets on both the motherboard and the adapter, as well as any other traffic on the PCI Bus.
 
You must log in or register to reply here.
Back
Top