USB Attached SCSI ( UAS ) or USB Attached SCSI Protocol ( UASP ) is a computer protocol used to move data to and from USB storage devices such as hard drives (HDDs), solid-state drives (SSDs), and thumb drives . UAS depends on the USB protocol, and uses the standard SCSI command set. Use of UAS generally provides faster transfers compared to the older USB Mass Storage Bulk-Only Transport (BOT) drivers.
20-560: UASP may refer to: USB Attached SCSI Protocol , in computing Pavlodar Airport (ICAO code), Kazakhstan Three Unit Assessments or UASPs, part of the Scottish Higher school exams Anarchist Union of São Paulo, an organisation; see Anarchism in Brazil USA Perpignan , a French rugby union club officially named Union Sportive Arlequins Perpignanais Topics referred to by
40-518: A built-in blocklist for devices with "quirks" defined in unusual_uas.h . Temporary additional quirks can be added via procfs or kernel command line ( usb-storage.quirks ). FreeBSD does not support UAS as of August 2018. On older operating systems that do not support UAS class, a UAS device may be run in USB Mass Storage Bulk-Only Transport mode for compatibility. SemiAccurate SemiAccurate ( S|A in short)
60-404: Is a U.S.-based technology-news and -opinion web site, founded in 2009 by Charlie Demerjian after his departure from The Inquirer . The site lists as its contributors: Charlie Demerjian (the site's founder), Thomas Ryan and Leo Yim. As of 2017 the site operates under a partial paywall model, making the majority of its content publicly available at no cost to readers - but subscribers to
80-569: Is complete". A brief hardware roundup in July 2010 by SemiAccurate found that Gigabyte Technology had introduced working UAS drivers for their boards using NEC / Renesas chips. A comparative performance review by VR-Zone in August 2011, concluded that only the NEC/Renesas chips had UAS working drivers. The same Renesas UAS driver (for Windows) also works with AMD's A70M and A75 Fusion Controller Hubs,
100-608: Is different from Wikidata All article disambiguation pages All disambiguation pages USB Attached SCSI Protocol UAS was introduced as part of the USB ;3.0 standard, but can also be used with devices complying with the slower USB 2.0 standard, assuming use of compatible hardware, firmware and drivers. UAS was developed to address the shortcomings of the original USB Mass Storage Bulk-Only Transport protocol, i.e., an inability to perform command queueing or out-of-order command completions. To support these features,
120-643: Is required to implement UASP, and not all motherboard manufacturers are prepared to pass on the extra cost of this license to the end user." A few Allwinner Technology SoCs feature UAS support over USB 2.0 in Linux. Of USB/SATA bridges, "the LucidPort USB300 and USB302, Symwave SW6315, Texas Instruments TUSB9261 and the VLI VL700 controllers all support UASP, while the ASMedia ASM1051 and ASM1051E as well as
140-597: Is slower than a SATA3 link, the performance will be limited by the USB link. However, USB has continued to improve its transfer rates, with USB4 reaching 80 Gbit/s. Many UAS drives are implemented using a SATA 3 drive attached through a SATA to UAS bridge, which limits the a UAS drive to the native SATA transfer rate, however a native USB UAS SSD can take full advantage of higher USB transfer rates. The UAS standard (ANSI INCITS 471-2010 and ISO/IEC 14776-251:2014) has been superseded so it should be referred to as UAS-1. A UAS-2 project
160-717: The International Committee for Information Technology Standards (INCITS) develops and maintains the UAS specification; the SCSI Trade Association (SCSITA) promotes the UAS technology. The USB mass-storage device class (MSC) Working Group develops and maintains the UASP specification; the USB Implementers Forum , Inc. (USB-IF) promotes the UASP technology. UAS drivers generally provide faster transfers when compared to
180-529: The "Student-" and "Professional-"level tiers receive access to special analysis articles and reports on industry trends similar to white papers . In February 2010, SemiAccurate ran a story on the yet to be released, " Fermi ", microprocessor from Nvidia , which called the chip, "Hot, Slow, Late and Unmanufacturable." In August 2010, a tip off from a reader helped SemiAccurate to cover Sony admitting to defective graphics chips in some of its laptops. News organization IDG credited SemiAccurate for first reporting
200-589: The Bulk Streaming Protocol was added to the USB3 specification, and Streams support was added to the USB host controller interface ( Extensible Host Controller Interface ). UAS is defined across two standards, the T10 "USB Attached SCSI" (T10/2095-D) referred to as the "UAS" specification, and the USB "Universal Serial Bus Mass Storage Class - USB Attached SCSI Protocol (UASP)" specification. The T10 technical committee of
220-533: The Fujitsu MB86C30A doesn't." Fujitsu lists some higher-end chips like the MB86C311A that do support UAS. ASMedia 1053-s and 1153 support UAS. Silicon Motion's SM232x family of USB Flash Drive (UFD) controllers offers full USB 3.2 UAS performance, reaching data transfer speeds of up to 2 Gbyte/s. Microsoft added native support for UAS to Windows 8 . Drives supporting UAS load Uaspstor.sys instead of
SECTION 10
#1733085682870240-480: The USB part of which was co-developed by AMD and Renesas. In October 2011, ASMedia USB controllers chips had gained driver support as well (they had support on the hardware side before). As for support by Intel Platform Controller Hub (PCH), an article in MyCE notes: "The native Intel USB3 UASP solution is only supported under Windows 8. To further complicate matters, not all Z77 motherboards support USB3 UASP. A license
260-450: The lone semiconductor design company in the BAPCo consortium . In response, Nigel Dessau, Chief Marketing Officer of AMD, published a blog titled "Voting for Openness" shortly after this story went up, and explained AMD's side of the story. In August 2011, SemiAccurate published two stories, one covering the specifications of Nvidia 's unreleased mobile graphics line up, and another covering
280-473: The older USB Mass Storage Bulk-Only Transport (BOT) protocol drivers. Although UAS was added in the USB 3.0 standard, it can also be used at USB 2.0 speeds, assuming compatible hardware. When used with an SSD, UAS is considerably faster than BOT for random reads and writes given the same USB transfer rate. The speed of a native SATA 3 interface is 6.0 Gbit/s. When using a USB 3.0 link (5.0 Gbit/s), which
300-656: The older Usbstor.sys. Windows 8 supports UAS by default over USB 2.0 as well. UAS drivers and products are certified by Microsoft using the Windows Hardware Certification Kit . Apple added native support for UAS to OS X 10.8 Mountain Lion; drives using UAS show up in System Information → Software → Extensions as IOUSBAttachedSCSI (or IOUSBMassStorageUASDriver, depending on the version of OS X) "Loaded: Yes". Drives listed with "Loaded: No" are defaulting to
320-453: The older, slower Bulk Only Transport (BOT) mode. This may occur if the drive's USB controller, the Mac's USB port, or any attached USB hub doesn't support UASP mode. The Linux kernel has supported UAS since 8 June 2014 when the version 3.15 was released. However, some distributions of Linux such as Ubuntu (from v11.xx onwards) have reported issues with some misbehaving hardware. The kernel has
340-405: The same term [REDACTED] This disambiguation page lists articles associated with the title UASP . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=UASP&oldid=1185560789 " Category : Disambiguation pages Hidden categories: Short description
360-568: The specifications of AMD's (one of Nvidia's direct competitors) unreleased mobile graphics line up. Softpedia , VR-Zone , TweakTown , and the Tom's Hardware Forum all credited SemiAccurate for leaking these specifications. On December 4, 2012, SemiAccurate moved from an ad revenue supported business model to a paywall business model. This paywall model had three tiers, Curious (free), Member ($ 200 per year), and Professional ($ 1000 per year). On May 5, 2013, SemiAccurate amended this model to reduce
380-419: The story. In May 2011, SemiAccurate published a story on Apple dropping Intel from its laptop line within a few years. This story was covered by a large number of U.S.-based as well as international news organizations. ZDNet and Barron's both weighed in on the validity of the story. In June 2011, SemiAccurate published a story detailing the scandal that led AMD , Nvidia, and VIA to leave Intel as
400-413: Was started by T10 but cancelled. That effort was resurrected as UAS-3 which is now a published standard (INCITS 572-2021). Apart from being based on later versions of other SCSI standards (e.g. SAM-6 and SPC-6 (both under development)) the technical author described the changes between UAS-1 and UAS-3 as follows: "allow the device to switch data transfers from one command to another before the current command
#869130