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The Medea G-RAID Trumps The
LaCie Big Disk Extreme

Originally posted August 23rd, 2004, by rob-ART morgan, mad scientist
August 24th, 2004 -- correction on conclusion about SD capture

The LaCie Big Disk Extreme takes two 250GB drives and "spans" them inside one FireWire 800 box with an Oxford 912 based bridgeboard. Voila! Instant 500GB FW800 storage device. And very fast, at least in write speed. Nothing like it anywhere -- until now.

The Medea Corp, maker of very fast, very fast digital video RAID boxes, has announced their 500GB FireWire 800 storage unit called G-RAID. It offers the same basic scenario as the Big Disk Extreme -- two big drives on one box sharing the same bridgeboard (and channel).

The picture on the Medea website doesn't do the G-RAID justice. The case is made of smooth, curved, aluminum with front and side grills. It looks very nice next to your G5 Power Mac. (The Big Disk sits on a side stand, thereby making it thinner but taller.)

In the tests below, you'll see the G-RAID and Big Disk are very close in performance. I also included a pair of LaCie d2 Extreme FW800 drives in a software RAID 0 array (dual channels*).

Note the speeds of the dual channel* LaCie d2 Extreme RAID pair compared to both the G-RAID and Big Disk. For maximum dual drive performance, two channels* are always better than one. And the only way to get separate channels to each hard drive is to put each in its own case with its own bridgeboard.

(* dual channels were created by connected one of the d2 Extreme FW800 drives to the G5's built-in FW800 port and the other d2 Extreme to a LaCie FW800 PCI card.)

But the G-RAID offers a unique performance dimension compared to striping two individual drives. A conventional RAID 0 set loses speed as the volume fills up. Not so with the G-RAID's hardware based RAID 0 setup. This is what we observed:

What you see is the G-RAID maintaining the same 79MB/s READ speed throughout the volume capacity while the d2 Extreme dual drive dual channel RAID 0 setup, though faster when "empty," progressively drops all the way to 63MB/s READ speed as the volume "fills" up.


The G-RAID's ability to maintain the same transfer speed throughout the RAID volume was most impressive. That fact coupled with the quiet cooling fan pulling air across the two drives through front and side grills, the G-RAID has a definite performance edge over the Big Disk Extreme.

In fact, the cooling fan should allow use of two Hitachi 7K400 drives inside the G-RAID bringing the total capacity to 800GB.

As for value rating, the Big Disk Extreme 500GB model goes for $499 compared to the G-RAID's $699 -- so the Big Disk wins on value. The Big Disk has one other feature I like. When you power down your Power Mac, the Big Disk powers down automatically, without you having to press the on/off button. (And powers back up again without having to turn it on.)

(The next two paragraphs were corrected on August 24th, 2004)

According to the requirements published by capture card manufacturers, the G-RAID and the Big Disk should both be adequate for SD video capture, even with a write speed less than 50MB/s. (Note ,however, that write speed of both units is no faster than a single FW800 drive.) Both should also be more than adequate for normal DV video usage.

If you want better write speed with dual FireWire 800 drives, then I recommend two single drive enclosures on separate FireWire 800 channels (like we did with the LaCie d2 Extreme setup in the graphs above) -- or a dual SATA drive RAID setup.

For HD video capture, you should consider the other video RAID products offered by Medea such as the Fibre Channel FCR2 or Ultra Wide SCSI RT3. Or you should consider the SATA RAID approach using kits like the G5Jam, SwiftData200, or Burly Box.


One Big Disk Extreme versus two d2 Extremes

External Serial ATA solution: The Burly Box

What's The Best Serial ATA Drive To Use In A Four Drive RAID 0 Set?

How About Two Big Disk Extremes On Separate Channels?

Which is faster, CardBus FW800 or Built-in FW800?

What Makes The Best 4 Drive RAID 0 Set on a G5 -- FireWire 800? Serial ATA? or Ultra320 SCSI?


As indicated above, we used three different Apple Macintoshes in testing:

An Aluminum G4/1.5GHz PowerBook using built-in FW800 port and LaCie FW800 PCMCIA CardBus card.

A G4/1.42GHz MP Power Mac using built-in FW800 port and LaCie FW800 PCI card.

A G5/2.0GHz MP Power Mac using built-in FW800 port and LaCie FW800 PCI card.

The FireWire 800 enclosures tested included:

A pair of 250GB LaCie d2 Extreme FireWire 800 hard drives/enclosures (both with Western Digital WD2500JB drives)

A 500GB LaCie Big Disk Extreme (contains two WD2500JB drives in a HW RAID 0 configuration)

A 500GB Medea G-RAID (contains two 250GB drives in a unique spanning algorithm that doesn't slow down as the volume fills)

If you are shopping for FireWire 800 products, be sure to check pricing and availability at the following websites:

FWDepot (enclosures, PCI controllers, CardBus controllers, RAID boxes)

Granite Digital (enclosures, RAID boxes, PCI controllers, cables)

LaCie (enclosures with drives, PCI controllers, CardBus controllers)

MacGurus (drives, enclosures, RAID boxes)

Medea (specializes in video RAID boxes)

Other World Computing (drives, enclosures, PCI controllers, CardBus controllers)

TransIntl (drives, enclosures)

Wiebetech (enclosures - with or without drives, PCI controllers)

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2004 Rob Art Morgan
"BARE facts on Macintosh speed FEATS"
Email , the webmaster and mad scientist