Posts Tagged ‘USB 2.0’
Corsair® Launches World’s Fastest High Capacity USB Flash Drive
Posted by Parkzone Corsair in Corsair on December 3rd, 2011
Fremont, CA (Vocus) August 14, 2009
- Corsair®, a worldwide leader in high-performance computer memory, power supplies and flash memory products, including solid-state drives, today announced the 128GB Flash Voyager GT, the world’s fastest high capacity128GB USB flash drive.
The newest Flash Voyager GT is based upon a revolutionary design that employs a unique dual-controller architecture to achieve SLC-levels of performance using MLC NAND flash memory. The 128GB Flash Voyager GT is able to achieve read speeds of up to 32MB/sec and write speeds of up to 25.6MB/sec, with the limiting factor effectively being the speed of the USB 2.0 bus and operating system overhead.
“High performance is a key requirement for super-high capacity flash drives, such as the 128GB Voyager GT, simply because it is able to store such a large volume of data,” said John Beekley, the VP of Applications at Corsair. “The 128GB Voyager GT is nearly twice as fast as other high-capacity flash drives, which means less time waiting for your music, video or office files to copy to and from the drive.”
The 128GB Flash Voyager GT also utilizes a durable and water-resistant rubber housing to protect the drive against accidental damage, and sports the racing-red ‘GT’ styling that is a trademark of Corsair’s ultra high-performance products.
“The 128GB Flash Voyager GT is ideal for those who need access to a huge volume of data in a format that’s convenient, durable and extremely fast,” said Jim Carlton, VP of Marketing for Corsair. “The 128GB Flash Voyager GT can store massive video, photo and music libraries, yet it’s less than half the size of a solid-state drive, effectively obsoleting less-reliable, portable mechanical hard disk drives.”
The 128GB Flash Voyager GT is available immediately from Corsair’s authorized distributors and resellers worldwide, and is backed by a 10-Year Limited Warranty. Complete customer support via telephone, email, forum and Tech Support Express is also available.
For more information on Corsair USB flash drives, please visit http://www.corsair.com/products/voyagergt_128
About Corsair®
Founded in 1994, Corsair Memory, Inc., is a worldwide leader in high-performance components for personal computers. Specializing in very high performance memory and ultra-efficient power supplies, our flagship products, Including Dominator memory modules, are the choice of overclockers, enthusiasts, and gamers everywhere. Our expertise in design and manufacturing is also evident in our complete line of Flash Voyager® and Flash Survivor USB storage devices. Corsair offers 24/7 customer support via forums and the Tech Support Express helpdesk. For more information, please visit http://www.corsair.com
Copyright© 2009 Corsair. All rights reserved. All company and/or product names may be trade names, trademarks, and/or registered trademarks of the respective owners with which they are associated. Features, pricing, availability, and specifications are subject to change without notice.
US & Canada PR Contact:
Robert Pearce
510-657-8747 ext 214
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In The Data Stage of a USB 2.0 Control Read Transfer
Posted by Parkzone Corsair in USB on February 21st, 2010
USB 2.0 device doesn’t return an expected handshake packet during a control transfer, the host retries. On receiving no response after a (typical) total of three tries, the host notifies the software that requested the transfer and stops communicating with the endpoint until the problem is resolved.
The two retries include only those sent in response to no handshake at all. A NAK triggers a retry but doesn’t increment the error count.Control transfers use data toggles (USB 2.0) or Sequence Numbers (Super- Speed) to protect against lost data. In the Data stage of a USB 2.0 Control read transfer, on receiving the data from the device, the host normally returns ACK and then sends an OUT token packet to begin the Status stage. If the device for any reason doesn’t see the ACK returned after the transfer’s final data packet, the device must interpret a received OUT token packet as evidence that the Status stage has begun.
Devices must accept all error-free Setup packets. If a new Setup packet arrives before a previous control transfer completes, the device must abandon the previous transfer and start the new one.
A USB 2.0 device has these responsibilities for transfers on a control endpoint:
- Send ACK in response to every Setup packet received without error.
- For supported control write requests, send ACK in response to received data in the Data stage (if present) and return a ZLP in the Status stage.
- For supported control read requests, send data in response to IN token packets in the Data stage and ACK the received ZLP in the Status stage.
- For unsupported requests, return STALL in the Data or Status stage.
USB 2.0 Transaction Are Very Short
Posted by Parkzone Corsair in USB on December 18th, 2009
The allowed delays between the token, data, and handshake packets of a USB 2.0 transaction are very short, intended to allow only for cable delays and switching times plus a brief time to allow hardware (not firmware) to determine a response, such as data or a status code, in response to a received packet.
A common mistake in writing firmware is to assume that the firmware should
wait for an interrupt before providing data to send to the host. Instead, before the host requests the data, the firmware must copy the data to send into the endpoint’s buffer and arm the endpoint to send the data on receiving an IN token packet. The interrupt occurs when the transaction completes. After a successful transaction, the interrupt informs the firmware that the endpoint’s buffer is ready to store data for the next transaction. If the firmware waits for an interrupt before providing the initial data, the interrupt never happens and data doesn’t transfer.
A single transaction can carry data bytes up to the maximum packet size the device specifies for the endpoint. A data packet with fewer than the maximum packet size’s number of bytes is a short packet. A transfer with multiple transactions can take place over multiple frames or microframes, which don’t have to be contiguous. For example, in a full-speed bulk transfer of 512 bytes, the maximum number of bytes in a single transaction is 64, so transferring all of the data requires at least eight transactions, which may occur in one or more frames.
