[clug] another rainy day time filler - CF reader

Eyal Lebedinsky eyal at eyal.emu.id.au
Mon Feb 15 00:57:36 MST 2010

Thanks Alex,

I expected this much. The cf is a "SanDisk Extreme 60MB/s 16GB" so it should not
be the bottleneck. I saw some benchmarks online where they got better numbers,
check the USB 2.0 unit here:

And the related blurb:

dd with different block sizes gave similar results as did plain cp.


Alex Satrapa wrote:
> On 15/02/2010, at 10:07 , Paul Warren wrote:
>> I'm fairly sure that USB 2.0 has a maximum possible transfer rate of 480
>> megabits/s, which is 60 megabytes/s.  But that is only the trasfer rate
>> for the USB transport.  USB protocol overheads take a significant whack
>> out of that, and there are fairly large delays between packets also.
>> - From my experience, the most you're going to get out of a USB connection
>> is 25 megabytes/s of actual data transferred.
> I have a WD "My Passport" drive which handles FireWire 800/400 & USB 2.0.  I get about double the transfer speed out of FireWire 800 (~50MB/s) as I do from USB 2.0 (~25MB/s), and not quite 50% more out of FireWire 400 vs USB 2.0.  USB is cheap for a reason.
> Having said that, I'm getting damned good performance out of my SanDisk Ultra II 8GB CF (it's a black label with red highlights) and my SanDisk ImageMate 12 in 1 "Certified Hi-Speed USB�" reader (model number SDDR-89 V4).  The card's rated at 15MB/s, I average at around 9MB/s.
> Alex

Eyal Lebedinsky	(eyal at eyal.emu.id.au)

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