2011/2/8 Bruce Walker <bruce.wal...@gmail.com>: > The wires support 480Mbps, yes, but once you load up the entire USB driver > stack the resulting actual in-use speed is much less than that. Have you > ever timed USB2 xfers? One word for them: abysmal.
Call them what you like, Bruce... :-) We are in agreement over the relative transfer rates of USB2 and FireWire. > True, my estimation of the achievable WiFi speed is based on my own use of > it around the house, You have 802.11n base stations? Cool. :-) Only up to the g spec myself yet. However I find that the throughput is far less than the theoretical max for the protocol. When copying files from my laptop to the PC, connecting through the wireless network is just not an option. _that_ speed is abysmal. :-) > but also from seeing a video demonstration of a 645D > user xferring raw shots to LR via that card. This photog was sending full > raw 645D shots to Lightroom in about 5 seconds or less. It takes a second or > two for each of my much smaller K20D shots to copy from the SDHC card to the > iMac through a USB2 card reader. Hmmm... The 645D raw files are 45-60 MB. To send a 50 MB file to LR in five seconds, you got to move 10 MB/s (80 Mbit/s). That's within the theoretical speed ceiling of 802.11n, but with full signal quality and no packet loss it can take only 20% overhead. I'm no expert on network protocol overhead, but it sounds like a tight fit even on a good day. Another limiter is that would require a SDHC card with minimum Class 10 speed rating. The EyeFi "Pro" card is Class 6. It's kinda hard to catch what the guy in the video is saying, <g> but my impression is that the five second uploads are from jpegs. I also get the impression that he change to raw files about 3 minutes into the video. The upload times are considerably longer then. Jostein -- http://www.alunfoto.no/galleri/ http://alunfoto.blogspot.com -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
