Hey Bit-Techies, I have 4 new seagate 80GB SATA HDDs, an Abit IC7-G Max board and a Promise 4xSATA PCI controller card. I have done some reading up on RAID but, never having gone the RAID path before, would appreciate some advice on the best setup. The IC7-G can do RAID 0 and RAID 1 (And RAID 0/1), but NOT RAID 0+1. Apparently it is pretty quick in RAID 0 using the boards inbuilt abilities. The Promise card can do all these and RAID 0+1. I would personally prefer RAID 0+1 (everything can just get dumped on the same drive then and v.fast read speeds off the 4 drives) but I think the promise card may not be as quick as the board? Anyone a RAID guru or has some RAID experience with this board or controller card can give me some advice on whether to go for a 0+1 on the promise card or go RAID 0/1 using the boards SATA abilities? All advice welcome. Cheers!
The promise card will probably be as fast for 2 reasons: Assuming you're using ICH5R raid then you have direct access to the 266Mbit nb-sb link hub when means you can get more of the full potential of 2x150MBit SATA disks (dont expect anything near those speeds though). However, the promise card is easier to setup and probably works better then the "onboard" solution intel have integrated into their ICH5R chipset. But you're limited to the PCI bus of 133Mbit which is shared between everything else on that bus - sound, network (unless you're using CSA GbE), etc
RAID 0 + 1 with Seagates shouldn't saturate the PCI bus, that would require them to shift 67MB/sec each and I don't think they are that fast at all. Even so, the difference in performance with these disks I don't think would be massive, whereas with drives like the WD Raptor that can saturate the PCI bus in RAID the performance hit is noticeable in benchmarks. I would use the promise card myself, the good thing with using a PCI card is if you change motherboards, you can keep the array intact by simply taking the card over to the new system, which saves breaking the array. With onboard SATA, the RAID config data is stored on a chip on the board, so if you change the board and re-assemble you'll have to reconfigure the array. With the card, the config of the array is stored on a chip on the card and as such you can move the array into another machine (of course, you may still have to format, but it saves the hassle of setting up an array every time, which is a PITA you can do without). The IC7-Gs ICH5R S-ATA controller could last time I checked only do RAID 0, and the board also has a silicon image controller that can do RAID 0 *or* 1. So basically, using just the boards controllers, you can have 2 arrays, one RAID 0 for boot, and one RAID 1 for backup I presume. This would yield 2x 80GB for boot, 160GB, and 80GB for storage (RAID 1 gives the space of a single drive, the other drive is a 'mirror' of the first), so 240GB then. But with a RAID 0 for boot, you have no redundancy for those drives. Using the card would let you do RAID 0 + 1 in a single array, which would give you 160GB of space, but with full redundancy. Take your pick , IMHO you have two options: 1) Using the boards controllers will let you have 2 arrays (a RAID 0 and a separate RAID 1), with 240GB usable space, but no redundancy for the boot drives in RAID 0. 2) Using the card - thisshould be no different performance wise, not so you'd notice, and would give you 160GB useable space with full redundancy, and the benefits of being able to move the whole array easily without needing to rebuild it everytime.
Wow! Fantastic responses that answer my question perfectly! Will - I really appreciate the in-depth response. Thanks mate! I will go for the Promise card and a RAID 0+1 setup based on your and Bindibadgi's advice. To be honest, I hadn't even thought about the aspect of ease of changing motherboards and am glad you mentioned it. Bindibadgi - Thank you so much for replying! I do plan on using the GbE built into the Mobo when I finish building/modding this computer. The promise card certainly does look easier to setup and, if it is likely to be as fast like you say, I'll go for this option. Cheers! Now that you have both had a hand in my project, please do keep an eye on the project logs over the next week as I will be posting my first installment(s) and would love to show you guys what I am working on.
