why do ide drives only spin at 7200 rpm while scsi goes up to 15k?

[dolph]

there's probably an easy answer that just relates to data transfer rates and that it wouldn't help ide drives to spin faster because they couldn't take advantage of it, but i was just curious

 

[Peter]

That's because the higher RPM is mainly for faster access latency ... an improvement which is nixed by the fact that IDE drives cannot reorder incoming requests.

So if you want to bring access latency down, you first go SCSI and, if still too slow, go for the really hot 15k rpm irons.

 

[sao123]

I'm kinda curious...
If the cost of manufacturing a SCSI hard drive/CDROM is approximately the same as manufacturing a IDE device...I know it is...

why is there sich a high level price difference between them on the market?
why hasnt SCSI replaced IDE as the data storage interface of choice?

 

[jasonpetras]

Two reasons: volume and market. With IDE drives, WD, Maxtor, et al, can sell a bazillion of them for a penny profit (I'm exadurating) and make lots of money and keep them in business. To further push down the cost, the fact that they will sell a bazillion means that the individual parts that make up the drive are much cheaper to come by. Now, SCSIs are largely made up of the same parts, but the price difference is due to the market they sell into. Business have a bunch more money than you or I, the IDE consumer. So HDD companies get a big team of marketers and a couple engineers to come up with a competitive advantage that they can sell to the business (guys with more money) for a higher margin. Which they do. To keep their profits rolling, they need to up the ante when the IDE drives close the competitive gaps. This is why SCSI has the 15k drives and IDE currently doesn't.

 

[Peter]

SCSI HDDs, luckily, aren't made from the same parts as IDE drives at all. Lower areal density, sturdier bearings, better motors, much more advanced firmware, spare capacity to quietly replace bad sectors ... tons of difference, all geared toward reliability and speed.

IDE HDDs in turn are all about lots of capacity for as little money as possible. Reliability is substantially lower than with SCSI drives.

If you're really serious about your storage, SCSI HDDs are cheaper in the long run. Just figure the downtime cost of one single HDD failure.

 

[Fallen Kell]

Two more reasons, HEAT and SOUND! 15k SCSI drives are very hot and very loud. They are built to be run in a system that is in a temperture regulated environment with losts of cooling fans blowing on the drive. They are also intended to be in an environment in which there is so much other background noise that no-one will notice the 50 or 60 db of sound that they emit cause there are 20 other fans or harddrives which are also causing that much sound already.

 

[Shalmanese]

hmm... Downtime costs eh? with Raid 1 or 5, that would be the cost of a single HD.

 

[tbates757]

WD 10K RPM IDE hard drives are coming out soon if thats any consolation, SCSI is only used in servers because of the noise and heat

 

[earthman]

Only used in servers? I have 3 of them whirring quietly in front of me now.

 

[tbates757]

ok, well are they 10k or 15k?

 

[Peter]

Originally posted by: Fallen Kell
Two more reasons, HEAT and SOUND! 15k SCSI drives are very hot and very loud. They are built to be run in a system that is in a temperture regulated environment with losts of cooling fans blowing on the drive. They are also intended to be in an environment in which there is so much other background noise that no-one will notice the 50 or 60 db of sound that they emit cause there are 20 other fans or harddrives which are also causing that much sound already.

With fluid bearings, noise is gone, and heat is substantially down.

Regarding reliability. Even in RAID 5 arrays, IDE drives have a substantially lower reliability. Remember, it's not just about drives failing altogether. It starts with simple things like automatic bad sector reallocation, which IDE drives don't do, neither on reads nor on writes.
And yes, under heavy use, sectors do go bad over time. With SCSI drives, noone will notice (not even the RAID controller) until the drive is out of spares (which is a lot of bad sectors), while with IDE, every single sector failure requires action. Data loss on writes might not even be detected ...

 

[vimkgt]

The ability to hot swap is also a big advantage for the reliability of SCSI drives, and so far as I know, IDE RAID Arrays don't support hot swapping.

 

[JoeBaD]

faster hamsters in the box

 

[Frangelina]

You change your scsi drives after years of constant and consistant work for a newer interface/controler. You changed your IDE drive because it blew-up at the wrong time but you can get over it.

 

[Mday]

it's all money. for the same throughput and size, you pay a lot more for scsi

 

[Vegito]

you pay more for scsi because you can get fancy controller like quad channel with 14 drive support in each channel = 56 drive in 1 machine = yay

also 15k drive wobbles a lot, when you're spinning that fast, they have to find way to stabilize it. seagate has a few technology that they own and they'll cash in on it till its obsolete..

EDIT: my scsi drives have 5 year warranty, ide has about 1

 

[mechBgon]

Originally posted by: Fallen Kell
Two more reasons, HEAT and SOUND! 15k SCSI drives are very hot and very loud. They are built to be run in a system that is in a temperture regulated environment with losts of cooling fans blowing on the drive. They are also intended to be in an environment in which there is so much other background noise that no-one will notice the 50 or 60 db of sound that they emit cause there are 20 other fans or harddrives which are also causing that much sound already.

I happen to have a Cheetah X15-36LP, which along with the new 15k.3 is using fluid bearings. The idle noise is not completely inaudible, but it's not as bad as some of the Maxtor IDE drives (you know the ones, they make that zzzzzing! sound) or even some video cards I've owned (GeForce2 GTS for instance).

As for heat, a look at Seagate's spec sheets shows it producing 12W, compared to ... oh hey, 12W for a Barracuda ATA V. I keep my Cheetah in an Antec fan-cooled HDD bay with a very quiet 18dB 18cfm 80mm NMB fan for cooling, and it's barely more than room temperature. So I'd say heat and sound are becoming less of a detriment than they once were.

 

[RobCur]

If you want reliability, why not just get 2 IDE drives? then copy one to another. Its like tires, one is more likely to blowout then 2, or more at the same time. IDE are not cheap and SCSI are just so ludicrously priced that average consumer would have to make a very big investment to even think about it. If I can get a decent motherboard for 51 bucks and CPU for about 31 bucks, why can't hd be this cheap as well and have nice capacity like 40-80gb for 30-50 dollars? The crappiest hd sold today, 20gb for 59.95, imo is again ridiculously high.

 

[Frangelina]

I boot with an 18 7200 Baracuda(very quiet) using a 10k2 73gig (machine gun sound without the freakin Zzzz's of old IBM) as the master closet. I backed up wirelessly in my sweetie's computer (WD 7200BB). If I open the pictures folder (about 1500) from the Quantum, I cannot scroll fast enough to see unedited pictures. When I open it with her computer, the digestion is remarkably slower. Yes I would like to have a nice 15k3 for birthday gift...I would never sell it back.

 

[mechBgon]

Originally posted by: RobCur
If you want reliability, why not just get 2 IDE drives? then copy one to another. Its like tires, one is more likely to blowout then 2, or more at the same time. IDE are not cheap and SCSI are just so ludicrously priced that average consumer would have to make a very big investment to even think about it. If I can get a decent motherboard for 51 bucks and CPU for about 31 bucks, why can't hd be this cheap as well and have nice capacity like 40-80gb for 30-50 dollars? The crappiest hd sold today, 20gb for 59.95, imo is again ridiculously high.

$110 isn't what I'd call "ludicrously priced." Think about it:

10000rpm x 1440min/day x 365day/year x 5 years = about 26 billion revolutions over the drive's lifespan. Show me another product that you can buy for $110 that is guaranteed to rotate 26 billion times at 50C or they'll replace it.

 

[ElFenix]

another reason is that you can't have large capacity drives at 15K. the platters are physically smaller and the tracks are farther apart for more margin and reliability.

 

[Chaotic42]

Originally posted by: mechBgon

Originally posted by: RobCur
If you want reliability, why not just get 2 IDE drives? then copy one to another. Its like tires, one is more likely to blowout then 2, or more at the same time. IDE are not cheap and SCSI are just so ludicrously priced that average consumer would have to make a very big investment to even think about it. If I can get a decent motherboard for 51 bucks and CPU for about 31 bucks, why can't hd be this cheap as well and have nice capacity like 40-80gb for 30-50 dollars? The crappiest hd sold today, 20gb for 59.95, imo is again ridiculously high.

$110 isn't what I'd call "ludicrously priced." Think about it:

10000rpm x 1440min/day x 365day/year x 5 years = about 26 billion revolutions over the drive's lifespan. Show me another product that you can buy for $110 that is guaranteed to rotate 26 billion times at 50C or they'll replace it.

The earth. It came with a warranty. If it breaks down, we get a new planet. It's rinda rusted though, a real fixer upper. A bit smaller, too, but it's better than nothing.

Ok, that was lame. You do have a point though.

 

[capybara]

Originally posted by: mechBgon
$110 isn't what I'd call "ludicrously priced." Think about it:

10000rpm x 1440min/day x 365day/year x 5 years = about 26 billion revolutions over the drive's lifespan. Show me another product that you can buy for $110 that is guaranteed to rotate 26 billion times at 50C or they'll replace it.

the rear two tires on my toyota: 6 foot diameter,
870 rev per mile X 75,000 miles = 65 million rev.
the earth: 1 rev per year X 4 million years = 4 billion revs
looks like the scsi hdd is more reliable than either one!

 

[Bushwicktrini]

Originally posted by: capybara

Originally posted by: mechBgon
$110 isn't what I'd call "ludicrously priced." Think about it:

10000rpm x 1440min/day x 365day/year x 5 years = about 26 billion revolutions over the drive's lifespan. Show me another product that you can buy for $110 that is guaranteed to rotate 26 billion times at 50C or they'll replace it.

the rear two tires on my toyota: 6 foot diameter,
870 rev per mile X 75,000 miles = 65 million rev.
the earth: 1 rev per year X 4 million years = 4 billion revs
looks like the scsi hdd is more reliable than either one!

I thought it was 1 rev/day and 365 revs/year?

 

[Fallen Kell]

Again I will re-iterate. Heat and noise are one of the issues. For everyone who has been quoting me and saying "You are wrong" etc., etc., "look at Baricuda V", etc., etc.... I will again say this. The Baricuda V is ONLY 7200 RPM!!! It is NOT 10k or 15k! Yes it has low noise and low heat, guess why, BECAUSE IT IS ONLY 7200 RPM!

Yes, fluid dynamics are helping out. Yes, it is cutting down on the heat. But it still has not cut them down enough. If you havn't noticed the trend in the desktop environment, the trend is for cooler, quieter systems. Well guess what, 10k RPM drives are much hotter and louder then 7200 drives. With people specifically purchasing drives because of how quiet they are and how cool they run, manufacuteres will not produce a drive that only gets an approx 10-15% performance increase when they get a 30-50% heat and noise increase. Most people today, given the choice, are recommending a drive that is quieter and cooler then one that is hotter and louder, even at the expense of performance. Why did people pay the 50-60% priemium on the IBM DESKSTAR line when they first came out? They weren't the fasted thing on the market, they where close, but they were clearly beat in sustained file transfers. As well as edged out in several other categories. So why did people buy them and pay 50% the going rate for diskspace for them? Because they were quiet.

Same thing right now. Why are people buying the Baricuda V? It isn't the performance king. It probably ranks 3rd or even 4th. So why are people buying them? BECAUSE THEY ARE QUIETER AND COOLER! I can't state this enough. The market is currently in a push for quiet and cool systems. So that means the majority of sales will be because your drive is quiet and cool. The extreme niche market are the only people who are demanding a sacrifice of quiet and cool for performance. Manufacturers want to sell as many drives as possible, not limit themselves to a sub-group of people who want high performance IDE drives. If you want high performance, there already is a SCSI product already built with that in mind. The desktop trend is quiet and cool. Thus the desktop drives are going to focus on quiet and cool.