Which one is faster?

Do you have a question? Post it now! No Registration Necessary.  Now with pictures!

Threaded View
I am trying to update a seven year old computer. My 20GB hard drive should
probably be replaced. What is faster, a 9ms read IDE PATA drive connected to
the IDE on the motherboard, or a 9ms read SATA drive, connected to the
motherboard via a SATA controller? Any noticeable difference?



Re: Which one is faster?

Walter R. wrote:
Quoted text here. Click to load it

IIRC, 9ms is the seek time.  Time for the heads to move from track to
track.  Has little to do with data transfer.  (except of you drive needs
defragging).   But in general SATA is faster.   If you gave the model
#'s of the drives, someone could respond a bit better.
Also note that the type / speed of the controller has a lot to do with
it.  You could have a super fast IDE drive and put it on the worst
controller and defeat your purpose.

Again none of those specs we have.     So all in all not much help.

Re: Which one is faster?

Walter R. wrote:
Quoted text here. Click to load it

The extra performance of the SATA interface, only helps for smaller data bursts.
Once you start transferring larger files, the head to platter interface becomes
the limiting factor.

For example, the second generation of SATA runs at 300MB/sec. The cache on the
disk might be 8MB in size. If you wanted to write some data, the data could be
stored in the cache memory chip on the disk. On some motherboards, the transfer
might be 220MB/sec or so, into the cache. That would seem fast, except the
time is relatively short anyway, so you aren't doing a lot of waiting around.

If you have a 1GB file to transfer, the first 8MB might go into the cache chip.
But the cache is first in, first out, and so from now on, the cache can only go
as fast, as it is being drained. The head-to-platter interface is 70MB/sec, so
that is as fast as the write cache can be drained. After the first 8MB has
been transferred and the cache is full, now the disk transfer slows down.
And 70MB/sec is now slower than an IDE cable might be (100MB/sec or higher).
The IDE cable could easily handle that sustained rate.

The IDE cable would have a lower burst speed to cache, so the first 8MB might
only transfer at 133MB/sec or 100MB/sec etc (or less, if there are chipset
limitations, such as might exist on older chipsets). When you are transferring
the large file, the IDE drive now has the same 70MB/sec limit as the SATA drive

So for burst write, SATA can be faster for small files. For sustained transfer
and equal platter technology, they are the same transfer rate.

In any event, if you go to the disk manufacturer web site, you can get
on a few more parameters than might be listed on the sales web site. And make
decision based on what you find.

The latest generation of disks, give a little more than the previous ones.
For example, I have a couple Seagate disks, and the new one sustains 72MB/sec
while the old one is about 60MB/sec or so. So there is room to shop around and
compare specs.


Re: Which one is faster?

"Walter R." wrote:
Quoted text here. Click to load it

The speed differences will be small, and probably not noticeable.
The odds are that measurements will slow the SATA to be minisculy

 [mail]: Chuck F (cbfalconer at maineline dot net)
 [page]: <http://cbfalconer.home.att.net
            Try the download section.

Re: Which one is faster?

On Sun, 6 Jul 2008 15:41:04 -0700, "Walter R."

Quoted text here. Click to load it

First I should state that even a significant measurable
difference, for example 20%, might not be so noticable in
use, especially if this aging system is used with older less
bloated software and working within it's reasonably
sustainable performance limits which wouldn't be realtime
manipulation of huge files.  Even in worst case no matter
which alternative I've mentioned below would apply, you're
most likely to end up with performance differences under
30%, probably even under 20%.  The close you get to 0% the
more difference there could be in which various drive you
pick, the other PCI devices you use and how the system is
being used when the drive performance matters most.

I am assuming that when you wrote above, "connected to the
motherboard via a SATA controller" that you mean an SATA PCI
card, since (IIRC) the typical seven year old system doesn't
have motherboard (southbridge) integral SATA.  Because of
this, the PCI bus causes the SATA performance to be below
what you would see with southbridge integral SATA, lower
than performance from motherboard southbridge integral PATA
_IF_ your integral PATA is ATA133.  If it is ATA100, and/or
the drive you choose is ATA100 instead of ATA133, then in
many uses the performance could be similar to SATA over a
PCI card _IF_ all else were equal such as drives which
internally perform the same other than this data port or

If the system uses other PCI cards with moderate to higher
data throughput, or the motherboard chipset has a poorer
implementation of PCI such that the achieved bandwidth is
lower (notibly Via chipset boards of the era and (thinking
back, not sure exactly what era and tech the system is based
upon) some Sis chipset(s), then the limited bandwidth the
PCI bus can offer must be shared between a PCI drive
controller and the other devices on that bus.  Effectively
this can mean that even a basic drive performance benchmark
that isolates drive performance could give a performance
figure higher than you might see in actual use of the system
when the other PCI cards had been put to more use.

You'd asked about performance but I would tackle this from
another angle- that since there isn't necessarily a
substantial performance increase using SATA and possibly
worse performance, there seems no justification to spend the
extra time, money, nor increase complexity of the system in
order to implement SATA with one exception - if you
anticipate you will later pull this drive out of the system
and want to reuse it on a system new enough that the new
system has a limited number of PATA ports, possibly not
enough ports to support all the PATA devices you might want
to attach to it in which case having a drive with the bus
that is native to the new system would do a similar thing as
PATA would do for the old system, decrease cost of having to
add a PATA controller card, and the complexity and keeping
unnecessary data off the PCI bus.

Ultimately I'd tend to go with a Seagate ATA100 (PATA) drive
as the prices are competitive but they offer a longer
warranty.  That is, unless your motherboard only has ATA66
support instead of ATA100 or 133.  If only ATA66 then the
PCI SATA card attached SATA drive will usually be a little
faster unless you have a lot of other PCI traffic like a
gigabit ethernet card very frequently and continuously put
to use for higher bandwidth activies like large LAN
fileshares - not just broadband internet access.

Finally, it could be that your system won't support a drive
larger than 128GB requiring 48bit LBA bios support.  If it
can't, maybe a bios update will allow this support.  If it
doesn't support 128GB and larger, and there is no bios
update that will allow it then you have a couple of
remaining options.  Use whatever the board will support, for
example it's likely to support at least 32GB and many drives
have a capacity jumper limiter on them to put them in this
compable mode, though you loose so much capacity but perhaps
a system at this age doesn't hold very much data, running
older software and OS?  The other option is the PCI, SATA or
PATA133 controller card because it would have an onboard
bios that supports capacities >=128GB without need for the
motherboard bios to have >=128GB support.

Re: Which one is faster?

Thank you for your very comprehensive response. I learned a great deal from
what you said.
Have a great day.
Quoted text here. Click to load it

Site Timeline