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Super slow transfer time

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Dan ColinsSuper slow transfer time
by on Mar 5, 2014 at 4:59:06 pm

During downloading of various formats, I experienced unusually slow transfers. I tried isolate the components and still had many problems.

The problems seem to be when going to 2 different G-Raid Mini drives. I got a lacie rugged drive to work at normal speed when coping 90 and 40 gigs ~20 mins via usb3.0. The G-Riad (raid 0) was taking 3+ hours to copy 90Gid via usb3.0 or esata. I tried connecting directly to macbook pro and also through esata hub. I thought it might have been one bad drive, but the other drive had the same slow speeds. I tried different cables to no luck.

The original media being transfered was Red mags and also a SSD with ProRes files.

Does anyone know what might have been going on here?

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Chris MurphyRe: Super slow transfer time
by on Mar 5, 2014 at 5:22:06 pm

This is a confusing post.

1. 90 and 40 gigs ~20 mins via usb3.0
It makes no sense that a 90GB and 40GB transfer would take the same amount of time. But 40,000 MB in 1200 seconds is only 33MB/s which is slow. Even 90GB in 20 minutes is 75MB/s which is not exactly a speed demon either.

2. 10800 seconds to transfer 90,000 MB is 8MB/s. Obviously something is wrong. This is the sort of transfer rate you get with a.) bad drive; b.) bad connection; c.) improper alignment of either the raid to the physical sector, and/or file system to the raid; d.) small file random I/O. e.) other.

So that leaves c and e. And I don't know what e would be. And c is a pretty obscure problem to have these days, and HFS+ doesn't even permit alignment options because it really isn't designed/optimized for use with RAID.

What sort of results do you get from Blackmagic Disk Speed Test for each drive? You can get this from the App Store for free.

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Dan ColinsRe: Super slow transfer time
by on Mar 5, 2014 at 6:35:42 pm

Sorry, if you had trouble understanding my post. The time refered to the latter size, it took 20mins to do 40gigs over usb3.0.

I can tell something is wrong with these speeds, but I'm not a hardware expert to figure out what. When troubleshooting, I changed cables, changed type of cable (esata to usb) and tried a new drive, the new drive was just as slow.

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Chris MurphyRe: Super slow transfer time
by on Mar 11, 2014 at 5:56:26 pm

Use Blackmagic Speed Test from the App Store. Either post the result, or if you're convinced they indicate a problem or departure from the G-Technology specs then I'd call G-Technology and ask them what's up.

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