IDE RAID Examined

Bender writes "The Tech Report has an interesting article comparing IDE RAID controllers from four of the top manufacturers. The article serves as more than just a straight product comparison, because the author has included tests for different RAID levels and different numbers of drives, plus a comprehensive series of benchmarks intended to isolate the performance quirks of each RAID controller card at each RAID level. The results raise questions about whether IDE RAID can really take the place of a more expensive SCSI storage subsystem in workstation or small-scale server environments. Worthwhile reading for the curious sysadmin." I personally would love to hear any ide-raid stories that slashdotters might have.

Comments

Re:A little story

[tmark]

their big old file server had 5 hard drives in it, but was only using 1 in windows! Being the smart boy that he is, he dutifully shuts down the machine, removes one of the drives, puts it on the broken machine, formats and loads windows on it.

So how did he decide which of the 5 drives he was going to pull ?

Re:My experience with IDE RAID....

[Phosphor3k]

Thats bullshit. Post some links to benches that back that up.

Two 80GB WD special edition drives in RAID 0 (7200RPM, 8mb cache) rarely burst over 90MB/s. They usually have a sustained transfer of ~50-65MB/s.

Additionally, your seek time is going to suck. I gaurantee its not going to be under 11ms. You cpu utilization during transfer will prolly be around 4% in the asolute best case senario and 11% on average. This is becuase, no matter what you think, all raid cards under ~140$ do the calculations for the transfers in software, not hardware. All you have is a controller card with special drivers. You wont come even close to beating the overall performance of a scsi 160 drive, or SCSI 160 RAID 0 setup.

Re:SCSI for workstations?

[aussersterne]

Ummm, no.

Try getting sustained data transfer rates out of an IDE RAID under load. It won't happen. You'll stutter. *boom* goes your realtime process.

SCSI RAID, on the other hand, streams happily along with very little CPU load.

Re:SCSI for workstations?

[GT_Alias]

Ehhhh...RAID vs. RAM/Dual CPU's? I was under the impression people used RAID for data integrity (at least, that's what I use it for). Unless you're striping, I suppose.

So yeah, you could probably spend your money on other things to get better performance, but that's entirely besides the point. What could you spend that money on to get better data reliability?

Re:SCSI for workstations?

[prisoner-of-enigma]

You apparently didn't read the article, and have no current experience with IDE RAID systems. Take at look at the sustained tranfer rates of the 3Ware system. They meet just about any SCSI controller you're likely to find when paired with good 7200RPM drives. The myth that SCSI is the only way to get reliable sustained transfers is just that -- a myth. SCSI's only advantage now is reduced cable clutter and having up to 15 drives on one controller, but who needs that many drives these days when 120GB drives are available for next to nothing?