View Full Version : Let's compare RAID and SerialATA.


pirata
6th December 2002, 17:27
It is my intention in this thread to gather insight about latest hard drive technologies, in order to provide some help to help those planning to upgrade their systems (e.g. me! :-) ).

I think it is clear that, as CPU power and bus bandwidth grow higher and higher, more powerful HD subsystems are needed. Maybe I am wrong, but I even think to remember reading in a specialized tech publication (probably PCMag/ExtremeTech) that HD is becoming the actual bottleneck in nowadays systems.

Faster HDs mean faster swapping, shorter application load times, faster data editing. Many of us are involved in audio/video (AV) editing. While AV encoding needs much CPU a little HD speed, editing uses to be on the contrary, and the speed limitation is, of course, your HD.

RAID has definitely hit the streets, while SerialATA is slowly getting hotter. These two technologies are seem to be the next big thing in desktops for the next year. It is my intention to gather some comparative data about them.

SCSI could also be an option, but I think it is not mainstream and doesn't seem ever going to be. I don't know exact prices, but it is enough for me the fact that it is not in the hardware lists fo local PC-shops in this country (I guess they keep it for their corporation customers).

My point of view, which I invite you all to comment on, is as follows: serial ATA seems to be just a new interface between traditional magnetic technology and the chipset. Higher speeds on the chipset/HD bus just provide for an idler bus, not higher transfer speeds. It is true that higher data densities increase read/write speeds, but it does also in normal ATA drives, and they are much cheaper! And now ATA is going ATA133, which will be still cheapier than SerialATA (I haven't got prices for SerialATA, but I guess it will the "expensive choice" when it appear).

On the other hand, RAID seems a really speedy but cost-effective solution, since multiple reading/writing mechanisms can work at the same time. If you buy 2 drives, you get the same magnetic tech/high data density plus speedy 133ATA/8MB buffer and, above all, 2 read/write mechanisms. It could be as expensive as SerialATA. Maybe cheapier, as HD pricess are getting lower.

The only caveat for RAID is the already known problems with RAID drivers, but it seems to be a bother only for apps that use real DOS mode, such drive image applications (which is not an unimportant matter, though).

So, to me, the questions is: one serialATA or 2 standard ATA drives put in a RAID array?

Thanks to those who contribute with their knowledge!

Marc

P.S.: IBM seems to be pushing a new HD magnetical material that provides for even higher data densities. It seems to be an easy to introduce modification in current HD desings. Does anybody know how is it doing?

baz00ie
8th December 2002, 03:15
Higher data density sounds promising...

A real determining factor for transfer rate is the RPM of the disk itself. As the disks get faster, they get hotter and their life-span gets shorter. If they can increase the data density while keeping the rotation speeds - then there should be a significant increase in transfer rate. That, however, is the big trick - the read/write heads will have to keep up.

It's a "wait and see" at the moment.

later
joe

gabest
15th December 2002, 09:58
Isn't RAID possible with SerailATA? I don't know about any integrated or pci-card RAID controller for SerialATA yet, but I'm sure highpoint/promise/... will make one some day.

UGAthecat
16th December 2002, 08:52
even if no one makes a serial ATA raid controller in the near future, you can still do raid in software using win xp (and also 2k i think).
This software raid implementation provides the exact same redundancy and/or speed improvements as a normal raid implementation, but at a small cpu performance hit (about 2%-8% on about 1.5ghz systems with full load on the drives).
so, when capturing video, you may have less cpu available for encoding if your using something like huffyuv or xvid at a really low quant; but, when doing an actual conversion from one format to another your hd doesn't access as frequently, so the cpu hit will probably make less than 1% difference in encoding speed.

Anyway, I think we are still about 6 months to a year away from widespread adoption of serial ata, but once it is it will eventually completely replace regular IDE/ATA interfaces, so I'm sure somone will make raid adapters for it.
Serial ATA isn't that much different from current standards, in fact you can buy converters to go to and from serial ata and regular IDE already, although due to low demand they are not cheap (about $30 U.S.)
As far as IBM coming up with something to increase the density of data on hard drives...its not surprising, they are a hard drive manufacturer, and if they done come up with something to squeeze more into less space they will fall behind in the future.

TactX
16th December 2002, 13:19
Originally posted by UGAthecat
even if no one makes a serial ATA raid controller in the near future, you can still do raid in software using win xp (and also 2k i think).

Windows NT Server does allow soft raid, too.

pirata
16th December 2002, 18:15
There are already MOBOs with serial ATA RAID integrated on board. Look for serialATA RAID in any motherboard price watch site (unluckily I don't remember the name of the concret site, but there is a bunch of them around).

mad_professor_2002
28th December 2002, 09:28
I have a ABIT AT7-MAX2 Motherboard with 2 Standard IDE ports, 2 IDE Raid Ports, & 2 Serial ATA Raid Ports, It also comes with an convert so that you can conect your standard IDE harddrive into your new Serial ATA Port.

pirata
28th December 2002, 17:57
Are you sure that the onboard SATA controller is also SATA-RAID capable??

mad_professor_2002
28th December 2002, 18:16
Yes but please go and have a look for your self.
Here's the url.

http://www.abit.com.tw/abitweb/webjsp/english/pt_main_back.jsp?pPRODUCT_TYPE=MotherBoard&pMODEL_NAME=AT7-MAX2

Hope this is of some help.

masken
29th December 2002, 15:38
One of the performance benefiting factors of SATA is that every disk has it's own channel directly to the motherboard.

Dont see why SATA couldn't be RAID'd, there's no reason why not. In fact I think it's going to be a good alternative for servers too in the near future.

chemmajik
4th January 2003, 06:24
SATA is a cheapo unproven esp RAID standard, the problem is it doesnt have time behind it to prove if its dependable in long term use. Besides it may turn out to be a obsolete standard before it even gets near a standard. The motherboard manufacterers are hyping it so much bec its alot cheaper to place on the motherboards. Its like the same old situation, would you rather have a software codec, software modem, software raid etc or a hardware one. Even the hard drive company's havent truely jumped into fully supporting it. But when it comes to multitasking I dont care how fast the standard is, I see pause & wait state issues until its gotten the kinks out of its revised standards sure to come. It reduces costs is the only reason behind the overhype, I'll take scsi or ide raid anyday in parallel over serial, which has been proven to be the best for the last 10yrs(scsi) or more by mainframes that need multi-use most, IDE has had alot younger life span, esp the raid version, but its proven to be successful with raid 0+1 or 5 better yet. 150Mb SATA is cool sounding in theory, but is it sustainable? sorry for babbling...

ps: Personally I dont think the Abit MAX series was there best product to date, alot of fraggers understand why.