Choosing a Raid 5 Controller (PATA)

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Robizzle01

Limp Gawd
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Sep 30, 2005
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I'm looking for an affordable raid 5 controller to use with four or five (I would prefer five) 200gb ata/100 hard drives. It also must work in Gentoo linux running on an amd64 system (if that makes any difference.)

(I picked up 3 drives on black friday for $20 each and a friend of mine bought two more for me since the limit per customer is 3.)

I started my search at newegg and quickly realized that I didn't know much about the subject. After further research, I have only become more confused.

First of all, PATA allows two devices to be connected to a single cable. Would a controller with two ide connectors allow me to connect 4 hard drives? None of the controllers that have only two ide connectors have support for raid 5 so i'm guessing the answer is no. Also, even if I could, would I want to or would this be a major bottleneck?

Next, how much slower is a controller that doesn't have support for hardware XOR? I imagine it would push all the calculations onto the processor but how bad would this be on a amd64 3000+?

Any other advice or links to additional reading would be greatly appreciated. Thanks in advance for any help.
 
Robizzle01 said:
I'm looking for an affordable raid 5 controller to use with four or five (I would prefer five) 200gb ata/100 hard drives. It also must work in Gentoo linux running on an amd64 system (if that makes any difference.)

(I picked up 3 drives on black friday for $20 each and a friend of mine bought two more for me since the limit per customer is 3.)

I started my search at newegg and quickly realized that I didn't know much about the subject. After further research, I have only become more confused.

First of all, PATA allows two devices to be connected to a single cable. Would a controller with two ide connectors allow me to connect 4 hard drives? None of the controllers that have only two ide connectors have support for raid 5 so i'm guessing the answer is no. Also, even if I could, would I want to or would this be a major bottleneck?
Click to expand...

You will get 4 drives on there. I am not sure if PATA really has RAID5 cards available. Unless you are in a production environment (which it sounds like this is just for yourself), you will not notice the bottleneck.

Next, how much slower is a controller that doesn't have support for hardware XOR? I imagine it would push all the calculations onto the processor but how bad would this be on a amd64 3000+?

Any other advice or links to additional reading would be greatly appreciated. Thanks in advance for any help.
Click to expand...

I am of no help for this part.
 
Linux software raid is probably a reasonable thing to do. It's plenty fast, and doesn't take much CPU time. And you can buy cheap controllers. And you could (theoretically - I don't recommend it) mix sata and IDE drives. And it migrates from machine to machine or controller to controller just fine.

 
You can look arround for used LSI i4 Megaraid cards, which are also sold as Dell IDE raid controllers. They are 4 channel PCI cards for up to 8 drives. Not sure about linux support, but they are pretty old tech, so there should be.
 
unhappy_mage said:
Linux software raid is probably a reasonable thing to do. It's plenty fast, and doesn't take much CPU time. And you can buy cheap controllers.
Click to expand...

Excuse my newbness but could you point me in the direction of these cheap controllers? I clicked around newegg and was unable to find a PATA controller that would support 5+ drives that was _not_ a raid controller card (and imo expensive.) Maybe I am best off getting http://www.newegg.com/Product/Product.asp?Item=N82E16816102027 and only using 4 of my hard drives?
 
Robizzle01 said:
Excuse my newbness but could you point me in the direction of these cheap controllers? I clicked around newegg and was unable to find a PATA controller that would support 5+ drives that was _not_ a raid controller card (and imo expensive.) Maybe I am best off getting http://www.newegg.com/Product/Product.asp?Item=N82E16816102027 and only using 4 of my hard drives?
Click to expand...

Promise is a nice controller, but I am experiencing some issues with mine. Sometimes I get extremely slow transfer rates (20-40 Mpbs or even slower). I have not had issues with my SIIG (not sure of exact model, but it is IDE). I do not use raid, just as something so I have extra drives.
 
You can get hardware raid 5 IDE cards but not in a 2 channel from what I can recall. Something like this offers all the features of a scsi raid controller (OCE, hot spare, even hot swap) but they are still going for around $200 on ebay. Also even though its a 4 channel, it only supports 1 drive per so you would still be facing the 4 drive dilema. Kind of a trade-off that only you can decide on.

 
Should you decide to go with a hardware based solution ... I'd second Aronj66's LSI MegaRaid i4 recommnedation. Its a nice short PCI card with four ATA channels and a i960RS integrated I/O processor. With patience, you can pick one up off ebay for a very reasonalbe price.

While the i4 does support up to 8 drives, I suggest that you would go with 4 (1 per channel) and retain the 5th drive as a spare for the array.
 
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