I took
the THREE
FASTEST ULTRA ATA/100
drives
tested recently and stuck them in a
Granite
Digital
"Oxford 911" FireWire enclosure to see how fast
they would go. Like me, many of you like the
fact that you can jerk a drive out of your G4
Tower and shove it into a FireWire case.
But then, will it go faster in a FireWire case? slower? I got bit of a shock with the Apple 'generic' FireWire enablers. Take a look at this graph:
Using the
Apple 'generic' FireWire extensions, the speed
of of the Barracuda dropped from from 41MB/sec
to 23MB/sec! But then I reformatted it using
FWB's
HD Toolkit 4.5 and used FWB's
FireWire extensions (Library and Governor), the
speed went back up to 29MB/sec. I wondered if
FWB
knows something that Apple (and all the other
driver makers) don't know because all three new
test drives ran faster under FireWire when
FWB
drivers were used.
FWB didn't
reveal any secrets but did remark that these new
drives are a challenge for FireWire case and
driver makers because they exceed the usable
bandwidth of a Mac FireWire system (and probably
any other). This means that the FireWire bus
will not be able to empty the buffer on the
drive as fast as the media fills it. It's like
having a Ferrari engine that revs to 10,000 rpm
and installing a rev limiter that forces it to
misfire at 5000 rpm.
At any rate,
the graphs below show how fast the fastest Ultra
ATA drives go when put in a Granite
Digital
FireWire case and run with the FWB
drivers.
(The
WHITE
bars indicate three FireWire units that come
prepackaged with drives as a
reference.)
PERFORMANCE
ANALYSIS
The IBM 60gxp
seems to be the "happiest" of the three fastest
Ultra ATA drives in a FireWire case. The Maxtor
D740X was the second fastest. The Seagate
Barracuda ATA IV came in third place even though
it came
in first place when used as a pure Ultra ATA
drive inside the G4
tower.
Goes to show you that you can't assume a fast
Ultra ATA drive will be equally fast in a
FireWire case.
Thanks to
FWB
HDToolkit, these three fast Ultra ATA drives
performed as well as the best "prepackaged"
FireWire drive units. Unfortunately, no drive
runs as fast in a FireWire case as it does
inside the G4 tower using the Ultra ATA
interface. (See my soliloquy below.)
Note the very
good Quicktime Playback speed of the Maxtor
3000DV. It's obviously optimized for DV
playback. Maybe that's why they call it
"DV."
If you have a
G4 tower and want extra storage and the fastest
transfer speeds, I suggest you install extra
drives inside the tower (which holds up to 4)
and get either the new Tempo ATA100 PCI
controller card from Sonnet
or the new 6880M True Hardware RAID ATA-133 PCI
controller card from Acard.
(Read my REPORT
on these two Ultra ATA controller
cards.)
If you are
like me and often move a drive back and forth
between the inside of the tower and a FireWire
enclosure, you'll want a drive that doesn't take
a large performance hit when running in FireWire
mode. In that scenario, the IBM 60gxp earns the
"fastest drive on both interfaces"
award.
WHY IS
FIREWIRE IS SLOWER THAN ULTRA
ATA?
People are
often dazzled with the theoretical "400 megabits
per second" rating of FireWire and think that if
they put an Ultra ATA/100 drive in a FireWire
case, it will go "wicked fast." Not so. The 400
megabits translates to 50 megabytes per second
(MB/sec). The ATA/66 internal interface of the
G4 tower is capable of 66MB/sec. The Tempo
ATA100 PCI controller from Sonnet is capable of
100MB/sec. So Ultra ATA still has the edge over
FireWire.
Also, since
there isn't such a thing as a true FireWire
drive, the Ultra ATA drives are used in
conjunction with a FireWire-to-ATA bridge board
to create the FireWire storage unit. You can be
sure that something's lost in the translation.
Some of the bridge boards don't even use 80
conductor cables. FireWire engineers indicate to
me that the usable bandwidth of a FireWire
enclosure/bridge board is a good amount less
than 50MB/sec.
Even if Apple
releases 800 Mbits/sec FireWire, the drives
still won't go any faster. Even if faster
FireWire bridge boards are invented, the
ultimate bottleneck is the drives themselves.
The fastest drive in the group has a maximum
sustained transfer rate of 41MB/sec. That
doesn't come close to the 50MB/sec theoretical
rate of FireWire or the 66MB/sec theoretical
rate of ATA/66.
Until faster
drives and FireWire subsystems are invented, the
only way to make FireWire storage go faster is
to create striped arrays using RAID software...
but that's another story. STAY TUNED!
TEST
NOTES
The test
"mule" was an Apple
Power Mac G4/800MP running OS 9.2 with disk
cache set to 512K (to diminish effect of system
caching), AppleTalk OFF, Virtual Memory OFF, and
Extensions set to minimal (BASE).
TESTS
DRIVES:
Seagate
Barracuda ATA
IV
(ST380021A) 80GB 7200rpm ATA/100
Maxtor
DiamondMax Plus
D740X
(6L080L4) 80GB 7200rpm ATA/100/133
(note model number ending in "L4" has fluid
dynamic bearing motors)
IBM
Deskstar
60gxp
60GB 7200rpm ATA/100
TEST FIREWIRE
ENCLOSURE:
Granite
Digital FIREVue™
FireWire 1394 / Ultra IDE CASE KIT
TEST
"PREPACKAGED" FIREWIRE DRIVES
EZQuest
Cobra 60GB 7200rpm
Maxtor
3000DV 60GB 7200 rpm
VST/SmartDisk
full height 45GB
WHERE TO
BUY
NewEgg.com
(last time I checked) had the IBM and Seagate
drives in stock. They had the Maxtor D740X model
but not with fluid dynamic bearings. If you want
the fluid bearings, you'll want model #6L080L4,
not model #6L080J4. (No reseller seems to have
it yet.)
Another good
source for drives is Other
World Computing.
They carry a full line of Macintosh products
including their own line of FireWire enclosures
(with and without drives).
Looking for a FireWire case?
The case I used in the test was the one from
GraniteDigital.com.
It was the fastest of the "driveless" FireWire
enclosures I've tested. It's the only case I've
tested that uses 80 conductor cable between the
bridge board and the drive. It can be a bit
noisy as it has two fans (one for the power
supply and one for the drive).
It's a bit of an ugly
duckling in a time where sleek cases are the
rage. I like the clear Elite "911" case that
Other
World Computing is
selling. FWDepot
sells a nice looking thin "driveless" case that
includes a fan. It's called the "TT3.5" and does
have the Oxford 911 chip set.
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© 1995-2007 Rob Art Morgan
"BARE facts on Macintosh speed FEATS"
Email
, the webmaster
