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SATA vs. EIDE hard drive: what's the difference?


I was just looking at new high capacity hard drives, after reading Joel's latest post.

Is the new SATA (Serial ATA I think) compatible with a PC that has an EIDE hard drive? Or would I then need a SATA controller, etc. ? (i.e., like using a SCSI drive).

Sorry for the dumb question.

The real Entrepreneur
Tuesday, January 20, 2004

You need a SATA controller. Lots of motherboards come with these on board in addition to the EIDE and cards are available. The technologies don't conflict, but they are definitely not interchangeable.

Dustin Alexander
Tuesday, January 20, 2004

Maxtor has a FAQ page about SATA:

As Dustin says you need either a controller card or SATA capabilities on the motherboard. Many disk drive SATA retail kits include a PCI controller card for SATA.

Philip Dickerson
Tuesday, January 20, 2004

be aware with sata, most of the bios needs upgrade even if they have sata controller on that.

both mine and my friend sata drive didn't work when we bought it. he changed it to a 'normal' drive, i changed it to another sata drive.

however it works for months now, once in every 2 month my pc do not boot for the first time, need to restart. the reason is that disk not found.

so i'm not sure if it's a mature technology.

Tuesday, January 20, 2004

High-end motherboards use the ICH5 Southbridge (part of Intel 875P chipset). ICH5 has 2 SATA ports integrated. Silicon Image is another chip manufacturer used for on-board SATA support

Tuesday, January 20, 2004

Right now the speed difference between SATA-150 and ATA-133 or ATA-100 is negligible.  Even 7200rpm drives can't usually sustain more than 50 megabytes/sec of transfer anyway, let alone 100, 133, or 150MB/sec.

Obviously the extra bandwidth comes into play when you've got multiple devices on a single IDE channel but if performance was really that critical you'd have every device on its own connector, right?  :P

John Rose
Tuesday, January 20, 2004

The primary difference is: SATA is the future, PATA is the past.

The SATA connectors are much more convenient, the cost increase now is negligable (and will flip as time goes on), and the ceiling is much, much higher. SATA has none of PATA's limitations.

But should you replace PATA drives today with SATA drives? No. Should you consider using SATA if you get a new PC or motherboard with SATA support, and you have to buy drives anyway? Definitely.

Brad Wilson (
Tuesday, January 20, 2004

Oh, plus, if performance is an issue, SATA has 10k drives available (36 and 72GB). PATA does not. An array of 10k SATA drives is damn fast. Server fast.

Brad Wilson (
Tuesday, January 20, 2004

You can also buy adapters between SATA and EIDE.  I'm not sure all configurations are supported, but you should be able to go between EIDE connectors on the motherboard and a SATA drive

Mike McNertney
Tuesday, January 20, 2004

Regarding performance of SATA drives:

"October 2003 'A Quick Look at SATA Disk Performance' Tom Barclay, Wyman Chong, Jim Gray - We have been investigating the use of low-cost, commodity components for multi-terabyte SQL Server databases. Dubbed Storage Bricks, these servers are white box PCs containing the largest ATA drives, value-priced AMD or Intel processors, and inexpensive ECC memory. One issue has been the wiring mess, air flow problems, length restrictions, and connector failures created by seven or more Parallel ATA (PATA) ribbon cables and drives. Large capacity Serial ATA (SATA) drives have recently become widely available for the PC environment at a reasonable price (1k$/TB). In addition to being faster, the SATA connectors seem more reliable, have a more reasonable length restriction (1m) and allow better airflow. We tested two drive brands along with two RAID controllers to evaluate SATA drive performance and reliability. Each disk delivers about 50 MBps sqeuential and about 75 read IOps and 130 write IOps on random IO. The cards saturate at 200MBps on sequential but scale linearly to 8 disks for random IO. A surprise is that software RAID1 generally performs best and is easiest to manage."

Jim Gray is a "Distinguished Engineer" in Microsoft's Scaleable Servers Research Group.

Philip Dickerson
Tuesday, January 20, 2004

Wow that's the first PDF I've seen distributed by microsoft.

christopher baus (
Tuesday, January 20, 2004

Brad's comment summed it up perfectly. A nice consequence of the new connectors is that they're a lot tidier and can result in greater air-flow round the case.

Tuesday, January 20, 2004

"You can also buy adapters between SATA and EIDE.  I'm not sure all configurations are supported, but you should be able to go between EIDE connectors on the motherboard and a SATA drive"

The only connectors I've seen adapt PATA drives for use on SATA controllers. I've never seen the inverse (although I suppose it could exist, why would you want to do that?).

Brad Wilson (
Tuesday, January 20, 2004

Hrm, I thought they had ones that went both ways, but I could be wrong.  Why would you want it?  So that drive manufacturers have an incentive to start making SATA drives right away without risk of reducing their market from people who still only have PATA connectors

Mike McNertney
Tuesday, January 20, 2004

I've accidentally ruined so many PATA cables (by pulling the socket thing off the ribbon) that I was really looking forward to SATA... But alas, the SATA connector is still a flimsy little plastic thing. It doesn't even lock in place.

I'm not sure what the whole point of ATA is these days; why not just use FireWire? (probably because the controller needed between the bus and the disk is still fairly expensive... but it would be so much nicer to run your whole storage system on one or more hot-plug FireWire busses)

Dan Maas
Wednesday, January 21, 2004

Out of curiosity, if more people used SCSI, would the prices come down to IDE levels? Or do the drive electronics mandate a minimum pricing?


Wednesday, January 21, 2004

Philo, the cost difference between SCSI and IDE drives is not just the interface.  Largely it is the market targetted by the drive makers.  They design their SCSI drives for business use, and therefore make them more reliable and faster.  IDE drives are for consumer use so they are made to be as inexpensive as possible.

It is possible to make SATA drives on par with SCSI drives, for a price.  I imagine it would be possible to make SCSI drives almost as cheap as IDE drives, but it is not worth it since there is not a mass market for SCSI drives, especially now with SATA.

Mike McNertney
Wednesday, January 21, 2004

I have heard that the Western Digital Raptors (the 10K SATA drives) actual share drive hardware with their SCSI cousins, which is why they're available in the common SCSI sizes (36GB and 72GB) and not in the more typical PATA sizes.

That certainly makes sense to my brain, but I can't verify it for sure.

Brad Wilson (
Wednesday, January 21, 2004

I am a Tech at a PC store in South Carolina..often they bother me into helping the sales staff..the biggest question most of our customers/sales staff cant answer is the difference between SATA and PATA or as the techno-weenies call it "regular hard drives" Because this forum pretty much saves me about a 15 to 25 minute education process for customers, I would like to thank you guys for having this thread up here for me to print and hand to people and let the PEBKACs slowly do the math themselves.  On a slightly related note tho...I haven't seen much thought being put out on one potential for SATA...I could be wrong but listen for a minute...the S in SATA is Serial..we have had serial ports for awhile and know how they work..USB (still a Serial Bus) made things of the nice things about USB being on a "serial bus" its biggest point of sale is "hot swapable" And from what I have been reading about all of the PCI-X stuff..being that everything there is going to be a serial bus..the most simple things like sound cards/modems/nics/ EVEN Video cards are gonna be hot swappable..(sweet)  Back to my original question..Granted that its not the primary drive that you have booted from and are now using an operating system on...would your SATA drive currently be hot swapable...or is that something that is currently limited by todays Parrallel interface bus south bridges.  Or am i the first to ask that?    (on a related note i know i have lost any and all ability to spell)

Dan Santis
Wednesday, February 25, 2004

i'm also seeking for the differents of PATA and SATA.
i'v lot of stupid question going to ask..... :P

Some people said that PATA is faster than SATA, in some case.

but the technical note, certified that SATA is much more better than PATA.

how is the PATA works when transfering data with 80 conductor IDE cable?

SATA transfering data faster, but is only 7 pin connector. how come can be faster than 80 conductor IDE? (i also understand that USB is faster than parellel port, but still wanna know the technical issue inside.)

How fast can SATA go?? 600mbps?

TQ ...and hoping someone could answer it. but if u think no need to answer also is stupid question only... :P

but please don't give stupid answer....althrough it is stupid.

Monday, March 1, 2004

Hi engineers,

I have a question to you.
I have a WD Caviar SE SATA drive, 160Gig, and my old ASUS P3B-F mother board that even it is old recently accepted PIII-800 CPU that I successfully overclocked to 920MHz.

Since it does not support even ATA-66 without controller, I have to buy it. Do you know if ATA-100 controller like Promise Ultra100 IDE ATA Disk Controller will work for SATA?


Alex Zarutin
Wednesday, March 3, 2004

Purely from a performance (gaming) point of view, how do the current crop of PATA and SATA drives match up? Also, how much difference does an 8mb cache vs 2mb cache make?
The price diffential between PATA Seagate 120Gb and SATA
Seagate 120GB(2mb, I haven't checked out 8mbs yet) is nearly 15%, 4400 bucks to 5600 bucks.
Also whats the advantages and Disadvantages of Maxtor vs. Seagate.
I also hear a lot of scare stories of how the PATA 2mb 120gb seagate is crashing a lot. Anyone heard anything?

Sunday, March 7, 2004

2 days ago I received my new motherboard with 4 integrated SATA connectors (and 3 IDE channels) and the Western Digital Raptor (72Gig) boots up my windows XP in about 1 minute :)

alex B
Monday, March 22, 2004


I have a 120 gb hard disk and a 300 gb hard disk in my asus a7n8x motherboard plus there are 2 sata ports on the mptherboard.

My question is this; Can I add a 120 gb hard disk to the sata interface and use all 3 hard drives in my computer, the 2 eide hard disks and the 1 sata hard disk?

Or will there be a conflict between the sata interface and the eide  with dificulties that will make it impossable to have access to to one or the other?

kind regards


robert allison
Sunday, April 18, 2004

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