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LarryJoe33

macrumors 68030
Original poster
Jul 17, 2017
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Boston
Just fired up my new Fw 800 external hard drive and did a clone of the internal SSD to it. 92GB in 32 minutes. Is this at 800 speeds? What’s the math?
[doublepost=1502367761][/doublepost]Sorry meant to put this in the MacBook Pro forum. I’m sure a mod will but still applicable I guess.
 
92 GB x (1024 MB / 1 GB) x (8 bit / 1 Byte) = 753,664 megabits
32 min x ( 60 s / 1 min) = 1,920 seconds

753,664 megabits / 1,920 seconds = 392.5 mbps

I don't have all that much experience with FW800, but it seems to me that this is faster than typical FW400 speeds.
 
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92 GB x (1024 MB / 1 GB) x (8 bit / 1 Byte) = 753,664 megabits
32 min x ( 60 s / 1 min) = 1,920 seconds

753,664 megabits / 1,920 seconds = 392.5 mbps

I don't have all that much experience with FW800, but it seems to me that this is faster than typical FW400 speeds.
Outstanding detail. Thanks so much.
 
FW 800 it is in theory 800mbps, but in practice is more like 500-600 mbps.
The maths are correct, a hard drive is full of small files, so 400mbps / 50MB/s is reasonable in average.
 
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https://techinternets.com/copy_calc?do

Type 92GB, select firewire and click the speed you wanna check. spoiler: It ran at FW400 speed (35 minutes).

The actual link may really have been fw800, but you got fw400 transfer rate over it. That may be due to controllers, harddrive speeds etc.
Thank you. I understand there are lots of variables. I should also note that this was using CCC and I am sure the software is analyzing, comparing etc. A better test would be a straight copy and paste of a large file.

I’ll take it though. The same transfer using CCC and a USB 2.0 2.5 inch spinner used to take more than 1.5 hours.
 
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I have a NewerTech Raid 1 box with some Seagate 7200 drives, and the speeds are in the 650 mbps range. In my experience CCC is slower than copy & paste but it never screws up.
 
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I have a NewerTech Raid 1 box with some Seagate 7200 drives, and the speeds are in the 650 mbps range. In my experience CCC is slower than copy & paste but it never screws up.

Nor should it the files copied using it should be bit for bit identical as it uses rsync as the engine for the transfer. It does a file checksum comparison on each and every file copied ensuring you get no errors once it says it has completed, that is something a simple copy and paste will never do.
 
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Nor should it the files copied using it should be bit for bit identical as it uses rsync as the engine for the transfer. It does a file checksum comparison on each and every file copied ensuring you get no errors once it says it has completed, that is something a simple copy and paste will never do.
Well that makes me feel good about my 400 speed given all CCC is doing and the quality of my CCC clone.
 
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