Difference between pages "RFID" and "SuperFetch"

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RFID stands for Radio Frequency IDentification. It typically applies to a technology that uses radio waves to automatically identify people or objects.  While there are various ways to identify, the most common is to store a serial number that represents a person or object identity and possibly other information, on a microchip that is attached to an antenna. Collectively the microchip and antenna represent a RFID transponder or an RFID tag. The antenna gives the chip ability to transmit identity information to a RFID reader. Then the RFID reader converts the radio waves into digital information that can then be passed to the computer for usage. RFID has been around since the 1970s. Since the radio waves from the low end of the electromagnetic spectrum, waves are safe as  radio waves from a car radio.
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RFID and Bar codes are different technologies and have different applications.  The big difference between the two is bar codes are line-of-sight technology. A scanner requires a bar code be brought towards a scanner in order for it to be read. RFID on the other hand, doesn’t require line of sight. RFID tags can be read as long as they are within range of a RFID reader. If a label is somehow removed or damaged there is no way to scan the item.
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SuperFetch is a performance enhancement introduced in [[Microsoft]] [[Windows|Windows Vista]] to reduce the time necessary to launch applications. SuperFetch works with the memory manager service in Windows to analyze memory usage patterns over time to determine the optimal memory content for a given user for a date or time of day. This differs from the [[Prefetch]] technique used in Microsoft Windows XP, which preloads data into memory without analyzing usage patterns.
  
Currently many forms and sizes such as personal items, services, and products use RFID worldwide. Currently in the United States, most public transportation such as trains, buses, and restaurants such as Mcdonald's all carry RFID receptacles that allow credit card transactions using MasterCard's PayPass. MasterCard PayPass is the payment feature that can be added to any MasterCard payment account to enable payments with a simple tap. PayPass is flexible enough that it can be built into cards or other devices such as key fobs, and can be used in markets that primarily issue smart cards or those that primarily issue magnetic stripe cards.  
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From [http://msdn.microsoft.com/en-us/library/windows/hardware/dn653317(v=vs.85).aspx]: SuperFetch prioritizes the following kinds of pages to remain in memory:
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* Pages of applications that are used most frequently overall.  
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* Pages of applications that are commonly used when resuming:
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** After extensive hibernation (for example, first thing in the morning).
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** After shorter periods of sleep or hibernation (for example, after lunch).  
  
InfoSync reported that, Motorola and MasterCard are conducting field tests of new mobile phones that include Radio Frequency Identification (RFID) chips embedded in them as part of a cashless payment system dubbed PayPass. The phones will be equipped with Near Field Communication (NFC) systems, which will allow them to communicate with nearby readers to, for instance, pay for small purchases or tickets for transit or events simply by passing their phone close to a reader.
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If SuperFetch detects that the system drive is a fast solid-state drive (SSD) (as measured by Windows Experience Index Disk score), then SuperFetch turns off [[ReadyBoot]].
  
Once the phone and account has been identified by the RFID tag, the user's MasterCard account will be billed automatically by the network for the appropriate amount. MasterCard also sees potential for the phones as contactless readers, which it claims opens the door for "a variety of marketing a
 
1000
 
nd promotional applications", on which the company did not elaborate further.
 
  
The PayPass trials will be run by the end of the 2006 at various locations in the United States.
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== Configuration ==
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Because SuperFetch appears to leave a system with no available memory, some users turn it off to create the appearance of having more free memory. The feature can be configured by changing the <tt>HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters\EnableSuperfetch</tt> [[Registry]] key [http://www.codinghorror.com/blog/archives/000688.html]. A value of zero disables SuperFetch, one enables it for booting only, two for applications, and three for both applications and boot. This setting can also be changed using the Services console, <tt>services.msc</tt> [http://tiredblogger.wordpress.com/2007/03/27/superfetch-not-so-super-for-gaming/].
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== File Formats ==
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Data for SuperFetch is gathered by the <tt>%SystemRoot%\System32\Sysmain.dll</tt>, part of the Service Host process, <tt>%SystemRoot%\System32\Svchost.exe</tt>, and stored in a series of files in the <tt>%SystemRoot%\Prefetch</tt> directory [http://www.microsoft.com/technet/technetmag/issues/2007/03/VistaKernel/]. These files appear to start with the prefix <tt>Ag</tt> and have a <tt>.db</tt> extension. The format of these files is not fully known, there is available unofficial partial specification [http://blog.rewolf.pl/blog/?p=214] and open source (GPL) dumper for .db files [http://code.google.com/p/rewolf-superfetch-dumper/]. Some information can be gleaned from these files by searching for [[Unicode]] [[strings]] in them.
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The SuperFetch feature is seeded with some basic usage patterns when the operating system is installed [http://channel9.msdn.com/showpost.aspx?postid=242429].
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== See Also ==
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* [[Prefetch]]
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* [[ReadyBoost]]
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* [[ReadyBoot]]
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* [[Windows SuperFetch Format|SuperFetch Format]]
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* [[Windows]]
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== External Links ==
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* [http://en.wikipedia.org/wiki/Windows_Vista_I/O_technologies#SuperFetch Wikipedia: Windows Vista I/O technologies - SuperFetch]
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* [http://channel9.msdn.com/showpost.aspx?postid=242429 Channel 9 Interview with Michael Fortin of Microsoft on SuperFetch]
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* [http://www.informationweek.com/news/showArticle.jhtml?articleID=196902178 Microsoft Predicts The Future With Vista's SuperFetch] from Information Week
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* [http://jessekornblum.com/presentations/dodcc08-2.pdf DC3 Presentation: My You Look SuperFetching], by Jesse Kornblum
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== Tools ==
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=== Open Source ===
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* [https://code.google.com/p/rewolf-superfetch-dumper/ rewolf-superfetch-dumper]
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[[Category:Windows]]

Revision as of 01:48, 24 April 2014

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SuperFetch is a performance enhancement introduced in Microsoft Windows Vista to reduce the time necessary to launch applications. SuperFetch works with the memory manager service in Windows to analyze memory usage patterns over time to determine the optimal memory content for a given user for a date or time of day. This differs from the Prefetch technique used in Microsoft Windows XP, which preloads data into memory without analyzing usage patterns.

From [1]: SuperFetch prioritizes the following kinds of pages to remain in memory:

  • Pages of applications that are used most frequently overall.
  • Pages of applications that are commonly used when resuming:
    • After extensive hibernation (for example, first thing in the morning).
    • After shorter periods of sleep or hibernation (for example, after lunch).

If SuperFetch detects that the system drive is a fast solid-state drive (SSD) (as measured by Windows Experience Index Disk score), then SuperFetch turns off ReadyBoot.


Configuration

Because SuperFetch appears to leave a system with no available memory, some users turn it off to create the appearance of having more free memory. The feature can be configured by changing the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters\EnableSuperfetch Registry key [2]. A value of zero disables SuperFetch, one enables it for booting only, two for applications, and three for both applications and boot. This setting can also be changed using the Services console, services.msc [3].

File Formats

Data for SuperFetch is gathered by the %SystemRoot%\System32\Sysmain.dll, part of the Service Host process, %SystemRoot%\System32\Svchost.exe, and stored in a series of files in the %SystemRoot%\Prefetch directory [4]. These files appear to start with the prefix Ag and have a .db extension. The format of these files is not fully known, there is available unofficial partial specification [5] and open source (GPL) dumper for .db files [6]. Some information can be gleaned from these files by searching for Unicode strings in them.

The SuperFetch feature is seeded with some basic usage patterns when the operating system is installed [7].

See Also

External Links

Tools

Open Source