Old HW or New SW RAID

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Hi,

I have an opportunity to get hold of a second hand hardware RAID card (Promise SuperTrak 100) very cheaply for my new home Win 2K server. My alternatives are a cheap RAID card (say less than

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Personally, I prefer to offload things to hardware wherever possible. Any CPU cycles that you can save will be to your benefit. Take for example the latest GPU/graphics cards – they are processing units unto themselves so as not to bog down the CPU with what is really a secondary task.

Whether the software based cards are any good would be subjective: how much CPU power is there? How fast is the system overall? What is its intended use? Software based cards will suffer from any bottleneck in the system and that’s a bad, bad thing. WIth hardware based processing, this is less of a concern. You need to measure the trade-off against your environment and personal requirements.

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Hi Mark,

I ended up getting an Adaptec 1200A which was OK (hardware at least) but it ended up being slightly inadequate because one of the drives I bought is flaky and it didn’t support RAID5 so when that drive crashed it took the entire array with it. I sourced a Promise SX4000 (again from eBay) as an alternative which not only supports R5 but also supports up to 256Mb cache. So now I have a 360 plus GB, 4 disk, R5 array that works rather well (I was hoping the flaky disk would fail but unfortunately I am still no wiser as to which one it is, perhaps this card thrashes the disk less through caching, so I will have to wait and hope that happens within the guarantee time!

Anyway thanks for your help 🙂

James

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Glad you got it up and running. Now as for that flaky drive…it will wait until you’ve gotten comfortable and forgotten it was much of a problem, and then fail spectacularly.

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Glad you got it up and running. Now as for that flaky drive…it will wait until you’ve gotten comfortable and forgotten it was much of a problem, and then fail spectacularly.

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Hi Mark,

I ended up getting an Adaptec 1200A which was OK (hardware at least) but it ended up being slightly inadequate because one of the drives I bought is flaky and it didn’t support RAID5 so when that drive crashed it took the entire array with it. I sourced a Promise SX4000 (again from eBay) as an alternative which not only supports R5 but also supports up to 256Mb cache. So now I have a 360 plus GB, 4 disk, R5 array that works rather well (I was hoping the flaky disk would fail but unfortunately I am still no wiser as to which one it is, perhaps this card thrashes the disk less through caching, so I will have to wait and hope that happens within the guarantee time!

Anyway thanks for your help 🙂

James

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Slight digression. I’m reminded of when I was in charge of a minicomputer here. Looking at the ‘main’ specs it really wasn’t any more powerful than the PC’s of the time-so I asked the manufacturer’s representative why it was so much more ‘effective’? (It really was-if I remember correctly it could handle up to 100 users, with basically dumb terminals (we used emulator cards but I believe that dumb terminals were an option), with a 16-MHz processor & 64MB of RAM.)

The answer I got was that it really had multiple processors. Only one was listed as the CPU but each I/O board also had a processor and the OS was written to take advantage of that. Sort of like PC’s are evolving into today with graphics co-processors, DSP chips on modems, RAID processors, etc.

Based on that experience I agree that for performance you should offload whatever processing you can from the CPU to other hardware. On the contrary side, I also had an Amiga years ago. It had separate processors for graphics, sound, and something else-don’t remember what now-in addition to the ‘main’ CPU. When it came time to upgrade it turned out to be a mess. Much easier to upgrade the single processor in a PC.

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Slight digression. I’m reminded of when I was in charge of a minicomputer here. Looking at the ‘main’ specs it really wasn’t any more powerful than the PC’s of the time-so I asked the manufacturer’s representative why it was so much more ‘effective’? (It really was-if I remember correctly it could handle up to 100 users, with basically dumb terminals (we used emulator cards but I believe that dumb terminals were an option), with a 16-MHz processor & 64MB of RAM.)

The answer I got was that it really had multiple processors. Only one was listed as the CPU but each I/O board also had a processor and the OS was written to take advantage of that. Sort of like PC’s are evolving into today with graphics co-processors, DSP chips on modems, RAID processors, etc.

Based on that experience I agree that for performance you should offload whatever processing you can from the CPU to other hardware. On the contrary side, I also had an Amiga years ago. It had separate processors for graphics, sound, and something else-don’t remember what now-in addition to the ‘main’ CPU. When it came time to upgrade it turned out to be a mess. Much easier to upgrade the single processor in a PC.

Reply | Quote

Personally, I prefer to offload things to hardware wherever possible. Any CPU cycles that you can save will be to your benefit. Take for example the latest GPU/graphics cards – they are processing units unto themselves so as not to bog down the CPU with what is really a secondary task.

Whether the software based cards are any good would be subjective: how much CPU power is there? How fast is the system overall? What is its intended use? Software based cards will suffer from any bottleneck in the system and that’s a bad, bad thing. WIth hardware based processing, this is less of a concern. You need to measure the trade-off against your environment and personal requirements.

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