This IS the Avid L2: [Avid-L2] G-Raid transfer speeds

Friday, May 9, 2014

[Avid-L2] G-Raid transfer speeds - USB3 vs Thunderbolt

I'm trying to understand why the transfer rates G-Drive claims for it's
G-Raid are quite different between the USB-3 and Thunderbolt versions.
On their website they claim the USB3 G-Raid does 250 MB/s, and the
Thunderbolt version does 327 MB/s - 30% faster.

But it seems to me the limiting factor in both cases would be the speed
of the underlying hard drives. I think both products use a pair of 7200
rpm drives raided together. I've always thought a single 7200 drive was
good for about 120 MB/s sustained, so a pair would get you around 240
MB/s. That seems to match the spec for the USB-3 G-Raid pretty well,
but not the Thunderbolt version.

Since both USB-3 and Thunderbolt interfaces are significantly faster
than the throughput of a pair of raided disks, why the difference?

Anyone have any real-world experience with the 2 variations, is there
really that much difference in speed?

At 327 MB/s, they seem to be getting about 160 MB/s per disk (which is
about the same transfer rate they claim for a single G-Drive) -- does
that match people's experience? I notice that LaCie, for comparison,
only claims an average transfer rate of 110 MB/s for their 7200 rpm
rugged drives, which seems more in line with the numbers I'm used to seeing.

Links to specs:
http://www.g-technology.com/products/g-raid
http://www.g-technology.com/products/g-raid-thunderbolt
http://www.g-technology.com/products/g-drive-thunderbolt
http://www.lacie.com/us/products/product.htm?id=10599

Thanks,
--Michael