What exactly is SATA?

[dgibson]

I'm looking at building a new system and looking at I865PE and 875P cards, and I am unclear as to exactly what the implications of SATA are. Ok, I know it's serial ATA and what that means in how it works (serial v parallel). But I'm unclear on whether it's simply a faster RAID interface for IDE or if it's a different drive standard altogether.

In other words, can I use my 2 IDE ATA133 drives for SATA or only on regular IDE RAID controllers (865PE)?

TIA,
Doug

 

[Ionizer86]

Totally different drive standard. You need IDE raid to use your two Maxtors together (exception here is that the Abit NF7-S board has an ATA to SATA adapter).

Oh and welcome to AT! This place owns (it's really addictive too....so run before it's too late 😉)

 

[Slogun]

Abit IC7-G also comes with an adaptor that allows you to connect most any IDE device to one of the 4 SATA ports.
Additional "serillel" adaptors go for $20 each.
Dont know if there is a performance improvement, (prolly not much at most) , but it is an option.

 

[StraightPipe]

usually not much of a difference in performance, but you can buy 10,000RPM SATA drives (ie: Raptor) that are much faster/expensive.

not cross compatable.

Welcome to AnandTech!

 

[dgibson]

thanks for the warm welcome and the info. That's about what I expected regarding the SATA stuff.

BTW - I've been an on and off again reader of Anandtech for many years. Just now found a reason to actually create an account and post. 😀

 

[o0moowear0o]

newb on sata drives, just expanding on the sata question.

so sata drives are basically faster drives which is the main benefit over standard drives?

 

[CQuinn]

so sata drives are basically faster drives which is the main benefit over standard drives?

No, SATA drives are pretty much the same as P-ATA (Parallel ATA) drives. The difference is the
cable that is used to attach them.

SATA uses smaller cables with less wires; that gives advantages in building systems and
reducing clutter/ improving airflow inside the case.

SATA can provide power as well as a data connection, which makes it simpler to hook up
devices.

SATA is a one device per channel connection, which eliminates the problems of master/slave
setup, or incompatible drive standards causing conflicts along the connection.

 

[dgibson]

That's interesting - I'm still earning specifics about how the interface is different and stuff, but from my research in pricing drives out, IDE is still way cheaper than SATA. I ended up opting for 2 Maxtor 80GB 7200RPM 8MB cache drives for average $60 each after rebates. I'll be picking up a mobo that supports IDE RAID to put them on soon.

Back tot he technical aspects of SATA though. Why the new format? What does SATA have over SCSI? IDE has bleen closing the gap in performance over the past couple of years, so what makes SATA worth it from someone's perspective who would choose SATA over IDE or SCSI?

 

[CQuinn]

Originally posted by: dgibson: That's interesting - I'm still earning specifics about how the interface is different and stuff, but from my research in pricing drives out, IDE is still way cheaper than SATA.

SATA is still a newer technology, newer = shinier = more demand = higher price.

Plus there are a few changes to the circuit board on the drives to better support SATA that adds to the
price difference. Also as SATA takes off, the PATA drives will slowly get phased out, which will make
them seem cheaper over the short term.

Back tot he technical aspects of SATA though. Why the new format?

Because they have been trying to use the same old cabling and connections for years with little
improvement. It was time for a change to something more future-friendly.

What does SATA have over SCSI?

Not much, SATA is an attempt to add some of the (newer) features of SCSI to the EIDE interface.

IDE has bleen closing the gap in performance over the past couple of years, so what makes SATA worth it from someone's perspective who would choose SATA over IDE or SCSI?

IDE still has a long way to go to really close the gap in performance, and there are limits to how far
it can be pushed using the old 40-pin wiring schemes. Most ATA cables these days have 80-wires because
half of them are just there as shielding against crosstalk along the wires that actually do the work.

SATA promises to be better than IDE for the reasons I gave above, plus future versions of the standard
can add on some features that are popular with SCSI devices now.

SCSI still has the lead, although the gap has been narrowed with the intoduction of large cache drives
and the Western Digital 10k RPM Raptors. SCSI isn't standing still either; the next great leap for it
will be Serial Attached SCSI (SAS) which will not only go to a cabling scheme identical to SATA, but
it is supposed to be able to support SATA devices as well.

 

[Matthias99]

Those are all excellent reasons.

It's also part of the continuing trend toward serial everything nowadays (PCI Express, for example, is another serial interface replacing a parallel one, and both USB and Firewire have been very popular). A big driver of this trend is that you can now build cheap, very high speed chips -- and the simpler the chip, the cheaper and faster it is. Serial interfaces require fewer wires and can be more easily and cheaply made to run at very, very high speeds. For portable devices, smaller cables and plugs mean the devices themselves can be made smaller.

SAS is basically a hack to trick legacy SCSI hardware into running over fiber optics or the like. However, if they can make it work with SATA, and squeeze some more performance out of it, it will probably kick around for a while before the market settles on one or the other as standard. However, the SCSI protocol is simply not designed for today's world -- it offers only minimal capabilities for sharing devices (important for MP servers and NAS devices), and it's not so great when it comes to hot-swapping physical drives. Newer versions are better, but still not seamless. SATA has the potential to fix a lot of these shortcomings, and it should also have more room for speed increases relative to traditional SCSI (though maximum SAS speeds may be similar).

 

[Jeff7181]

Unless you plan on buying a Raptor, or want a pretty case with pretty cables, there's no reason to buy a SATA drive. There is no performance difference between SATA and PATA... the performance difference you see, if any, comes from other improvements to the drive, not the interface.