The standard maximum cable length is 5 meters for USB 2.0 devices. USB 3.0 also offers an improved mechanism for entering and exiting low-power states, depending on whether a device is active or not, and eliminates power-consuming polling. The introduction of USB Battery Charging 1.2 specification allows up to 7.5W of power to be supplied to USB 3.0 devices. USB 3.0 has been designed to reduce power consumption while increasing its capacity to support and deliver more power. USB 3.0 improves upon this communication model and reduces transmission latency by minimizing polling and also allowing devices to transmit data as soon as it is ready. The high polling frequency not only increases power consumption, it increases transmission latency because the data can only be transmitted when the device is polled by the host. The host will frequently poll the device and ask for data, and the device may only transmit data once it has been requested by the host. USB 2.0 employs a communication architecture where the data transaction must be initiated by the host. The amount of current draw for USB 3.0 devices operating in SuperSpeed mode is now 900 mA, resulting in an increase in total power delivery from 2.5 W to 4.5 W (at 5 V). USB 3.0 also provides more efficient power management and increased power delivery over USB 2.0. The higher bandwidth also allows for faster frame rate, increasing the performance of the system. Users can now use fewer cameras while still covering the same imaging area with large resolution USB 3.0 cameras. This has created significant cost-saving opportunities for integrators as well as improving the overall system speed and efficiency. This important transfer mechanism has enabled machine vision camera vendors to build high-throughput USB 3.0 cameras. The effective bandwidth available via the bulk transfer method is around 400 MByte/s approximately 10 times that of USB 2.0. USB 3.0 has improved upon the bulk data transfer mechanism of USB.
Another important feature of USB 2.0 is that it supports Windows XP through Windows update. It also allowed for multiple high-speed devices to run simultaneously. With the increased bandwidth, high throughput peripherals such as digital cameras, CD burners, and video equipment could now be connected with USB.
It increased the data transfer rate for PC to USB device to 480 Mbps, which is 40 times faster than the USB 1.1 specification.
In 2002, a newer specification USB 2.0, also called Hi-Speed USB 2.0, was introduced. Besides different connectors used on USB 3.0 cables, they are also distinguishable from their 2.0 counterparts by either the blue color of the ports or the SS initials on the plugs.Ī successor standard named USB 3.1 was released in July 2013, providing transfer rates up to 10 Gbits/s (1.25 GB/s, called “SuperSpeed+”), which effectively put it on par with the first version of Thunderbolt. Among other improvements, USB 3.0 adds a new transfer mode called “SuperSpeed” (SS), capable of transferring data at up to 5 Gbits/s (625 MB/s), which is more than ten times as fast as the 480 Mbit/s (60 MB/s) high speed of USB 2.0.
USB 3.0 is the third major version of the Universal Serial Bus (USB) standard for computer connectivity. Summary of key USB 2.0 and USB 3.0 technical specifications. If you are like me and when downloading your pictures you want to see them right now get this reader.Table 1. Also, if you are using a slower speed card the speed difference will not be that great. If speed doesn't matter to you and while downloading you can go and do something else than stick with what you've got, also remember that your computer must have a USB 3 port. When Deklins reader became available, I bought it right away.
I've seen other USB 3 readers on the internet from companies I've never heard of so I passed on those. If you take a lot of pictures and when downloading them you want to see them NOW, then GET THIS READER.
The card I was using was a Lexar Professional UDMA 600X 32 GB card. The second was a Lexar Professional UDMA reader and finally the Delkin USB 3 reader. The first reader was a Sandisk 12 in 1 reader. I downloaded them using three different card readers. I shot 529 Raw photos with a Canon 7D totaling about 11.3 GB. About a week ago I received Delkins new USB 3 card reader and decided to do a little test.