USB transfer speeds?

[Phil Bloom]

Originally Posted by Bernard Racelis

I just exported a full 8GB card (about 27 minutes of HQ video) into MXF files to a hard drive in exactly 5 minutes using the Sony USB card reader/writer and the EX Clip Browser -- this translates to about 5X or about 220 Mb/sec,

8GB x 1024 x 1024 x 1024 x 8 bits/byte
-------------------------------------- = 229,064,922 bits / sec
    5 minutes x 60 sec

which is close to the specs of the drive which is 240 Mb/s (Read).
This is on a PC running Vista.

Ironically, on my notebook PC running XP which has a built-in ExpressCard slot and 7200rpm drive, it's slower (about 2X).

got nowhere near those sort of figures on my mac

[Brian Bledsoe]

Greetings Folks!

I'm a computer engineer and new to the forum. I didn't see a "New People" thread anywhere, so I'll just post away.

Although I'm new to HD video production, this topic and a few others are inside my area of expertise.

USB 2.0 can achieve real-world transfer rates up to 40 MegaBytes per second. So an 8GB card should transfer in about 3.5 minutes.

But if either the device or the host computer are not well designed, then you won't achieve those rates. Hard drives, motherboard, and device drivers are all factors. I would expect at least 25 MB/s regardless of what type of computer is used.

got nowhere near those sort of figures on my mac

I'm not sure about the latest generation of Macs, but I"ve heard the G5 did not implement the USB chipset or drivers very well. The were limited to about 18 MB/s, which would transfer 8GB in about 7.5 minutes.

[Brian Jansen]

using a PC laptop with an express slot
using sony clip browser by inserting a card into laptop.
< 8 gig card almost full / 5 clips =ing 7.2 gigs>
the copy to the laptop was about 5.5 mins
the export to mfx was the same

I put the card back in the camera and transfered the same files
using clip browser via the usb cable from camera to laptop.
It took a little less than twice as long at 9.2 mins

Not too shabby!! I can deal with that offload time using my mobil laptop.
I also got a deal on some sony 8gig usb thumb drives that can be used as backups... or just burn to the dual layer burner.
So I feel safe wiping a card that has been copied to the lap hd, usb drive and DVD-R.

[Paul Kellett]

I just got my Sony card reader,plugged it in,(plug and play),transfered 4mins of footage in 1 min.