XP Superfetch
Vista h3>
The following SuperFetch technology, ie "super pre-read", which evolved from PreFetch in the XP system.
Next, let's say what is prefetch:
In the Windows XP operating system, Microsoft has further improved virtual memory technology, and develops prefetch, The basic idea of taking technology is that before loading a program, the data required to run the program from the hard disk in advance to physical memory, so that the startup speed of the program can be accelerated.
In Windows XP, the specific way to use prefetch technology is to monitor the data exchange status of the memory page and the exchange file and other files on the hard disk when the system and application starts. Windows XP will require a hard disk file that often needs to be read when each program is run, and records the read case in the PF suffix name in the \ Windows \ Prefetch directory.
Once these PF files have been established, when each time you need to start the system or the corresponding program, Windows will first interrupt the program that is currently loaded, and go to find the \ windows \ prefetch directory, see if there is The current load program records, if there is a record, immediately follow the records of the required files in the program run during the program to physical memory. After this task is completed, Windows continues to load the interrupted program.
After such processing, when the program is run, when the file is read, since the file has been "prefetted" to the memory, it is not necessary to read it on the hard disk. Therefore, the phenomenon of frequent exchange of memory pages and exchange files during the program load is reduced, and the response speed of the program run is improved.
In order to further optimize the efficiency of prefetch operation, Windows XP also regularly analyzes the PF file, organizes the order of the program file load, and stores the information after these analyzes to \ Windows \ The layout.ini file in the Prefetch directory. At the same time, the disk defragmentation will also be notified that when the fragment is finalized, according to the content recorded by the Layout.ini file, the location of the associated file is in a continuous hard disk block.
This technology is fundamentally a passive scheduling. In other words, Windows will only perform related scheduling operations only when the program actively initiates load request.
The presence of passive scheduling may have some effect on system performance. We consider such an example, assuming that you have a habit of running anti-virus software at a lunch break, then before get off work, you usually stop processing the work program, then run anti-virus software, at this time, if you use Windows XP, then the operating system Write the memory page occupied by the work program into the hard disk exchange file and read the files of the anti-virus software to load memory. After the afternoon break, the anti-virus software has been running, but when you start using the work program, the system still needs to experience the switching of the anti-virus software and the work program, the switching process of the memory page, at which time the program's response speed is significantly reduced.
If the system can further automatically record the time of these frequent operation behaviors, the time of the operation, the front desk and the background software, etc., then there is a free space in the memory, you can In the predetermined timing, part of the file is loaded into memory, which avoids unpleasant conditions in the above example.
What is superfetch
, which is the problem that SuperFetch technology can solve in Windows Vista. Due to the new algorithm, Superfetch not only inherits all the advantages of Windows XP prefetch technology, but also further has the function of monitoring the status of the program, time and other details, and automatically presets the hard disk in accordance with the user's usage habits. The file is converted to the memory page, and the speed of the program that is frequently running is further accelerated.
SuperFetch technology center ideas is: "Excessive memory space is a waste". Indeed, if an operating system always retains excessive empty physical storage costs, it is not possible to use these excess memory space to improve system performance, why not better use these extra memory space? Use these excess physical memory as a cache, is the essence of SuperFetch technology. It is also because of the strategy of using this memory as a cache, it has caused Vista's hunger for memory capacity!
If you feel the stoffication of this technology, or the physical memory capacity is too small, it is also a choice to the Manage Tool-Service Close Superfetch service is also a choice. However, it should be noted that if you turn on the SuperTech service again, since the process of monitoring the user's usage habits is required, it is necessary to wait for a long period of time, and SuperFetch technology can re-enter the system to bring obvious speed of speed.
Open 2008 SuperFetch
First: SuperFetch's purpose is to upgrade the performance of the front desk process and prepare the contents of the recent process. The main purpose of Windows Server 2008 is to use as a server, with few reception processes, so no Superfetch technology is used. However, you can open:
Open the Registry Editor Find hkey_local_machine \ system \ CURRENTCONTROLSET \ Control \ Session Manager \ Memory Management \ PrefetchParameters This registry key
New DWORD item name is enableprefetcher value To 3
New DWORD item name is 3
open service, set the superfetch to automatically start successfully
Windows 7
superfetch
is not a new technology, which has begun to adopt in the Vista era, but in view of the number of people used Vista, the various computer skills in the XP era have always been deeply rooted. Many people are in question, how Windows 7 memory is so large.
Superfetch memory management mechanism will use the application page of the user to use the memory available space to preload; avoid the system from the hard disk from the hard disk as possible; let the application turn on; no Since the computer is idle, the sudden use becomes response slow; after exiting the large application, the previously forced transfer to the page in the virtual memory will re-transfer in memory. This seems to have a professional point, so it will look good to understand the characteristics.
Why is the first starter feel very slow?
I believe that everyone has a similar experience. When I started, I first run a program, such as Word, may take 5 seconds to start. When I closed, I will only use 2 seconds. If I don't close, open another Word file directly, it is faster.
What is this caused?
When we boot, there is no Word in the work set (page), he is still in the home (hard disk). So when I summoned him, it walked from home to the office (working episode). This process is called hard transfer, and of course the time required. And when we closed Word, he was sent to another room from the building. I immediately summon him again. At this time, the data in another room has not been cleared, and he doesn't have to come from home, and It is possible to introduce directly from the data structure. In the case where this program Word is not closed, he doesn't have to make the way for other programs, it still exists in the office (working episode), will summon him faster. This is not required to reuse data from the hard disk, but the process of re-mount the page in the data structure to the work set, it is called a softmore. Everyone knows that the memory speed is far from the hard drive, so the use of soft-tune pages is the second running program has become very fast.
Windows 7 memory occupies big reasons
to 2014, we know that when there is a program page in memory, the program will start faster. The SuperFetch in Windows 7 has a function of learning. Since the first time use Windows 7, SuperFetch began to record our usage habits, load the page of our frequently used programs after being loaded, then when we When the program is turned on, you can get the same speed like the second opening. So these preloaded pages will make our memory usage. Simply put to let all program operations in memory, avoid using hard disk hard-tuning page space, which is why Windows 7 takes a lot of memory.
View preloaded memory
and in the XP era, maybe you have a similar experience: After starting using some programs, it is left behind. When I came back, I found that the system responded very slowly, especially bad. This is because XP's memory management mode is very efficient.
When we leave, the program is in a non-use state. At this time, some background programs, such as disk finishing, anti-virus software, etc., will run at full speed, resulting in some of the programs we use to be squeezed into hard disk virtual memory. However, when these background procedures complete the task, the XP system does not guide the pages previously squeezed into the virtual memory. So when you use your computer again, the system will handle temporary provisioning, or even hard-tuning. The program response is extremely slow. So it looks like XP's free memory, and it doesn't work too much.
Using suggestions
Anyone wants to make your computer run the most ideal state by optimized means, and memory is a very important factor affecting computer running speed, we In the understanding of the memory management mechanism of Windows 7, you will introduce which methods can accelerate the system.
1, mostly used sleep and sleep
Because Superfetch is preloaded after boot, it is recommended that you should not shut down. Try to use sleep or sleep, so that Superfetch's preload will be retained. Thereby increasing speed and efficiency.
2, using readyboost
Many users rose from XP, because the system's memory is not large, so it is unable to fully exert the function of Superfetch. We can use the Readyboost feature to help us solve this problem.
As long as the eligible flash memory can accelerate our system. The READYBOOST function is to utilize the capacity of the flash as the storage space of the superfetch preloaded page. However, because Microsoft uses a special algorithm, it does not affect the life of the flash. Also, the flash memory for Readyboost is preferably 1 to 2.5 times the size of the physical memory. If the system is large enough, it is not necessary to use Readyboost. Right click on the U disk disk selection property, switch to the Readyboost column, and the speed reaches the standard U disk can open this feature.
Windows8
Windows8 / 8.1 Default to enable SuperFetch, which has a more obvious acceleration of the program response speed of usual use, especially when the large memory configuration is configured. Since Win8 / 8.1 users generally discovered that there is 100% of the short-lived disk after booting, it is considered to be one of the causes of slow system response after booting.
Using suggestions
Windows 8 To set up SuperFetch service
method:
Control Panel - Management Tool - Service - SuperFetch - Start Type - Automatic (latency start) (default start type is automatic without delay), you can avoid frequent access to the hard disk for hard drives, without recommendation.
Windows10
After Windows 10 1809, this service name has been changed to SYSMAIN.