2 HD's in IDE RAID vs 1 SCSI HD

[MrCraphead]

Assuming you had 2 of the best IDE HD's (i.e. 2 IBM 75GXP models) in a RAID 0 array, and then you had the best, fastest SCSI HD on the fastest SCSI form-factor available.......

Which would yield better performance?

I guess what I'm asking is, is IDE RAID better? or use 1 HD in a SCSI configuration?

 

[MrCraphead]

anyone?

 

[Sir Fredrick]

Better for what? Your best IDE RAID system will still have sluggish access times, the fastest SCSI drive would most certainly run circles around that in terms of access times...

In terms of raw transfer speed, I'm not entirely sure, but I'd be willing to bet that they're fairly close. But for your typical activities, you're going to be loading many small files, and that's where access times make the difference. There are only a few occasions where you'd be performing huge file transfers (200+ MB), and as I said the difference would most likely be minimal.

 

[Sir Fredrick]

Also, in terms of reliability, the SCSI drive will most likely take the cake. Most SCSI drives are built with reliability in mind, and come with 5 year warranties. When you use RAID 0 on two drives, you are literally doubling your chances of failure and data loss, because if either drive craps out, you lose everything.

 

[Radboy]

Craphead,

Like Fred said, depends what you wanna do with the drives .. capture video? audio recording? run an operating system & apps?

 

[MrCraphead]

I'd probably be doing the norm stuff, windows stuff, games, etc. I just wanted to know overall performance, and spec wise. thanks.

 

[Quickfingerz]

As far as price difference goes, You can do a 4 hard drive raid for the same price as one 15,000 rpm drive. Does a theoretical 148 mb/sec off of 4 IBM drives sound good to you?

 

[Radboy]

With thisrebate (good 'til end of the yr), and this free-shipping deal, you can get the Atlas 10K II (considered by some to be the fastest 10Krpm drive currently on the market) for $190 (215-25). 9GB is more than enuf room to run both W98/SE/ME & W2K .. prolly even a Linux distro, or two. Can also pick up a U2W/LVD controller here for $89 .. total cost = $279. How does 4.7ms seek time sound to you?

Storagereview says here that access times are much more important to system perf than STRs. Copy-n-paste:

".. STR had relatively little effect upon overall drive performance. Today, it should be clear that steadily-increasing transfer rates have in effect "written themselves out" of the performance equation ... it should be clear that random access time is vastly more important than sequential transfer rate when it comes to typical disk performance. Thus, the reordered "hierarchy" of important quantifiable specs would read:

1. Seek Time
2. Spindle Speed
3. Buffer Size
4. Data Density

<unquote>

 

[MrCraphead]

dang......are you serious QuickFingerz?!?

 

[DarkManX]

radboy I just placed an order for that setup.

 

[Sir Fredrick]

quick, don't forget about the RAID card, you'd want something hardware based unless you don't mind wasting a ton of CPU cycles...hardware based RAID cards are quite expensive.

 

[Radboy]

No sh*t?

 

[EvilDonnyboy]

how are you doubling your chances of data loss w/ raid 0? with Raid0, if one drive craps out you loose all ur data. true.

but with one drive, no raid, if one drive craps out, u still loose all your data.

if ur so worried about data loss, do raid 1.

 

[Radboy]

two drives have twice the chance of dying as one. RAID-1 offers no perf improvements.

 

[Xe0n]

well, if you have half your data on on drive and half on the other, and one drive dies you still have half ur data, but if u have 2 drives in raid 0 and one drive dies you loose all your data

 

[MrCraphead]

actually, RAID 1 provides faster seek/read times, since the same info is on 2 separate drives.

SO, IS it better to go with 2 HD in IDE RAID? or a really good SCSI HD?!? Which one would YOU go with?

 

[Xtremist]

Xe0n - I &quot;believe&quot; how striping works is let's say you want to store the word &quot;antidisestablishmentarianism&quot; on a 2 disk stripe array...

Disk 1 - atdssalsmnains

Disk 2 - niietbihetraim


Does that make sense? One is not good without the other... Of course, this might not be how it does it, although it wouldn't make sense any other way Oh, and I don't mean literally letter by letter, I'm not sure what type of chunks it writes to, just the &quot;method&quot; is what I'm trying to point out... Cheers!

 

[Sir Fredrick]

Raid 1 and Raid 0 are two different beasts entirely. I believe RAID 1 has lower or equal write times to a single drive system. RAID 1 has the great advantage of redundancy, so if one drive craps out you're still safe. Then there is Raid 0+1, but I *think* that requires 3 drives, I'm not sure. Anyway like I said, CPU utilization will be high with these unless you have a hardware based RAID card, and those things are extremely expensive. Most RAID cards are software based -> high cpu util

 

[Sir Fredrick]

See also: RAID info
More RAID info

 

[MrCraphead]

you're absolutely correct on RAID 0+1 Sir Fredrick, but I currently have a Promise Fasttrak ATA/100 IDE RAID card that I got for about $75 from buy.com. Not too expensive and not too shabby I might add......

 

[TimeKeeper]

Like Sir Fredrick &amp; Radboy said...

I'd like to add something if COST is the concern.

IDE RAID card ~$80
2 ATA100 20GB HD ~$250
Total around $350 shipped.

Tekram Ultra160 controller ~$170
1 18GB U160 HD ~$250
Total around $430 shipped.

If true performance is what you want, I don't see how extra $80 means anything.....
messing w/ 2 drives? no multi-tasking? theoretical performance?
hmm................interesting...............

 

[Sir Fredrick]

The promise RAID cards have high cpu utilization because they are not truly hardware based solutions. I also haven't heard many nice things said about their performance, but if you do decide to go IDE RAID, I'm very interested in hearing how it goes.

 

[RagingGuardian]

Adaptec makes an ATA66 Hardware based RAID card. Too bad it follows off it's SCSI brothers when it comes to performance.

 

[Xtremist]

MrCraphead - RAID 0/1 requires 4 HDD's I believe... It is mirror + striping... However, what you're thinking of probably is one of the other RAID's. What are the other popular ones? 3 and 5? Both of those use 3 HDD's I think... A quirky issue since he's probably only gonna do striping RAID anyway if he goes RAID at all Cheers!

 

[Sir Fredrick]

According to the second website I posted, you are correct, it takes 4 drives for 0 + 1. Raid 0/1 is not the same thing as 0 + 1, though. 0/1 is also known as Raid 10