RAID 0 and lower speed hard drives

[ThatDumbGuy]

I have an 8 gb ata66 5400 rpm hard drive (an older WD Caviar), and was wondering whether its better to just buy its twin and run raid 0, or buy a newer ata 100 7200 rpm of comparable size...

I know noone can really be exact here, but I'm asking for a generalization.

 

[Tschaft]

If you run raid, you always want to have EXACTLY the same drives.

 

[ThatDumbGuy]

Ack, I wasn't clear enough, I meant use two twin hard drives at ata66/5400 rpm, or use one at ata100/7200.

 

[tgeen]

I read a review of a RAID motherboard somewhere and the author stated it was generally faster to use a single, new 7200 rpm drive, rather than two slower (older) drives in a RAID setup. I don't recall for sure if there were benchmarks to demonstrate this, but I think so. Wish I could remember where I saw it.

 

[MustPost]

There was the AT RAID roundup, which pretty much showed one HD was better than 2 slower RAIDs. Indirecly

 

[Pabster]

First off, if you are even contemplating a software-based RAID solution, forget it. This includes the on-board RAID featured on mainstream motherboards. All striping is done by your CPU which means you are using as much as 25% CPU just to handle the RAID array. If you are serious about RAID, your best bet is to go SCSI and get a hardware controller. Mylex is a good start, but they aren't cheap. Yes there are IDE hardware controllers as well but that is also a poor choice.

A few other things - no, the drives need not be identical. You can create an array using an 8GB and a 10GB drive, for example - but you'll lose the other 2GB on the 10GB as it will only be an 8GB array. The drives can be different RPM as well. Is it a good idea? No, but yes it can be done. Again, you wouldn't see a performance benefit from such a situation. IDE drives fail much faster in a RAID configuration and as 99% of the RAID setups are software-based, you see no real world performance advantage. SCSI drives can handle it far better and will yield much higher performance.

It really bugs me to see the Sandra gang bragging about their 45000 score or whatever - I get that with a single SCSI drive and the numbers lie - Sandra scores mean nothing. Looking at real world performance is where it's all at. RAID + IDE is a terrible combination.

Now, for your "original" question - you are FAR better off with a single fast ATA/100 drive (like a 60GXP) than pissing around trying to RAID0 a couple old 8GB 5400rpm drives.