What is Swapping

By Dinesh Thakur

For improving the performance of the system we use the concept of swapping. In the swapping the processes those are on waiting state and those are on suspend or temporary suspend will be stored from out side the memory locations so that the speed of process will be high.

In this the process those are waiting for some input and output are transferred to the physical memory from they are running and the processes those are ready for the execution will be execute by the cpu.

When there is a situation to perform swapping, then we uses the sweeper. The sweeper is used for

1) Selecting which process to be out

2) Selecting which process to be in

3) Providing the memory space to the processes those are newly entered.

In this sweeper will select the suspended process then brings the ready process in memory and after the execution that suspended process will be again entered into the memory by the sweeper.

For swapping the sweeper also uses some address those are also known as the logical and physical address of processes. For providing the logical address into the physical address there the following two approaches used.

1) Static relocation. : In the static relocation swapping never to be performed because the process are always have a memory. Which is not to be changed at the execution time. For example the memory which is provided to the input and output operations and the memory which is provided to the cpu for executing the processes will not be changed so that this is also known as the static relocation of the memory.

2) Dynamic relocation. The dynamic relocation is also known as the memory which is changed and relocates by the processes at the time of execution. So that there must be some mechanism to provide memory those processes those are running. The mapping of the logical address into the physical address will be performed at the time of execution or at run time.

When the memory is provided to the process then the particular address is stored by the cpu which is also have a entry into the partition description table means in which partitions a process is running because when the process needs swapping that particular address must be reloaded.

Modify Windows “Swappiness”

Is there a modifiable equivalent of «swappiness» in Windows 7?

My system has 8GB of RAM which is more than enough for my day-to-day use. I’d like to modify swap behaviour, what *NIX systems call swappiness and set it to 0, as I’ve done on my Ubuntu machine.

I’ve searched the Web for this but all answers seem to be for *NIX systems.

2 Answers 2

Under Windows there’s something called «pagefile» where the system swaps applications to get the RAM free. I’m currently not at a Windows machine but the steps that Adobe put online here look right (I think Win + Pause is a shortcut to «Advanced System Settings).

Although it is possible to disable the pagefile, there are some concerns about that. For more information read this

There’s more to virtual memory than just «apps allocating RAM and when physical RAM runs out, something gets paged out to SWAP».

In Linux (and possibly UNIX at large), the system tries to keep pages recently read in RAM: programs executed, data loaded, data recently written (already on disk too) etc. So that if the same program gets executed again, it doesn’t have to get re-loaded from the disk. When some program asks for more memory to be allocated to its virtual address space, first the left-over disk buffers are re-purposed (without disk access). If this is not enough, some pages of running apps, that have not been accessed recently, get actually swapped out. On Linux, swapping normally doesn’t happen at all. Once your system starts swapping, you notice the increased drive activity (and sluggishness) and you go «oh what the f..» because it probably means that some app is leaking memory, or something under the hood has started spawning out of control.

Windows traditionally have a stupid additional habit, that they swap out whole user-space apps after some timeout on their inactivity. Strictly, without a pardon, just to have as much RAM available as possible, «just in case» you wanted to start yet another hungry app. If you leave your PC running, and you go away for a few hours, upon your return you notice that any app you switch into, it gets sloooowly reloaded from the swap. This behavior was particularly painful in Windows 2000 and is getting gradually less noticeable in more modern Windows versions. In W2k, turning off the swap was a no-brainer. Windows 7 can still ooze like honey sometimes for no particular reason, Windows 8.1 and 10 got noticeably better. but still there’s no tweakable knob for «swappiness», or other tuneable parameters of the swapping algorithm.

There are other factors that can lead to the system grinding along slow disk access. In Windows 7, you never know if the system has just swapped out your app in the good old W2k fashion, or if you should blame the Antivirus for the fact that your app is starting so slow, or if it’s Windows Update doing something in the background this time around (known to have reciprocating quirks in its algorithms that lead to hangs with 100% CPU consumption and/or disk thrashing), or if specifically some .NET Framework janitoring task got lost in the WinSXS database or what. On occasions / in some Microsoft software versions/incarnations, it actually seems that some windows-native «in the background tasks» (specifically Windows Update local database management) are deliberately «obscured» in the task manager, their CPU and RAM usage does not show in the total memory consumption. «Legitimate» activity, but pretty difficult to distinguish from a malware rootkit. Only once the thrashing stops and a balloon saying «new updates are available» instantly pops up, you know what the reason was.

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ARCHIVED: In Windows, what is a swap file?

A swap file, also called a page file, is an area on the hard drive used for temporary storage of information. Windows uses the swap file to improve performance. A computer normally uses primary memory , or RAM , to store information used for current operations, but the swap file serves as additional memory available to hold additional data.

Note: Microsoft recommends that you allow Windows to manage the Virtual Memory settings for you (i.e., leave the default setting as is). Only experienced users should change this setting, as it can adversely affect system performance.

Also note that you can manually move the location of the swap file to a different drive. In some situations, this can be advantageous. If you have a drive with more free space or a faster access time, you may improve performance by moving the swap file to this drive.

Windows 7 , Vista , and XP allow you to set up swap files for each drive on your system. In these versions of the Windows operating system, the swap file is dynamic and hidden.

Windows 7 and Vista

To view your current swap file information in Windows 7 and Vista:

From the Start menu, right-click My Computer or Computer , and then select Properties .

Note: If this doesn’t match what you see, refer to Get around in Windows.

From the Tasks menu, select Advanced system settings .

In the dialog box that opens, click the Advanced tab. Under the «Performance» section, select Settings. .

In the Performance Options dialog box, select the Advanced tab.

Click Change. . The swap file information is listed at the bottom.

Windows XP

The name of the Windows XP swap file is pagefile.sys , located in the root directory. The swap file is dynamic, changing size depending on system conditions. If you run several applications at once, the swap file will grow to accommodate the additional information required to run each application smoothly. This is a hidden file, so you will have to change your folder view setting to be able to see the file.

To view your current swap file information in Windows XP:

Right-click My Computer , and then select Properties .

Note: If this doesn’t match what you see, refer to Get around in Windows.

Select the Advanced tab.

Under «Performance», click Settings .

Select the Advanced tab. Information about your swap file is listed under «Virtual memory».

This is document ahbb in the Knowledge Base.
Last modified on 2018-01-18 12:43:28 .

How to change hard disk drives in Windows 10 with Hot Swap

Removing a hard disk drive from a personal computer is quite easy. Simply pull down the system and remove the drive. However, it’s a bit more complex when performing a hot swap. For those who are unaware, hot swapping is all about replacing a hard drive without shutting down the system.

This can be dangerous for the drive if not done correctly. One doesn’t just pull a SATA or eSATA drive out of the hardware without anticipating some problems. This is why we recommend using a software known as Hot Swap.

With Hot Swap, computer users can transform a regular SATA drive into a removable drive similar to USB/IEEE1394 drives. Well, now that is out of the way, let’s talk about how it works for the most part.

How to use Hot Swap to change Hard Disk

The size of Hot Swap is very small, so downloading it should take seconds. It comes in a .zip file, which means, the user must first extract the files inside to get to the real deal. There are two versions of Hot Swap when extracted; one for x86 hardware, and another for x64.

It should be noted there’s nothing to install. Just locate the version best for your computer, and launch it. Now, bear in mind that once the tool is launched, nothing will show up on the screen. That’s because it’s hidden, so simply fire up the “Show hidden icons” option in the taskbar and it should be there.

Interestingly enough, it looks similar to the “Safely Remove Hardware” icon, which is not a bad move. The color red is the big differentiator so no confusion between the two icons.

To remove a drive, left-click on the icon to view all swappable drives. To remove a drive, the user is required to select the drive from the pop-up menu. Keep an eye out for a balloon saying the drive has been successfully hot swapped. From here, the user can power-down the disk and safely remove it from the computer.

If a drive is in use by Windows or is colored gray, it cannot be removed.

The Right-click options

Right-clicking on the icon brings up the ability to scan for hardware changes. Furthermore, users can change the device type, the language, and even uninstall the Hot Swap tool should they feel the need.

If the user doesn’t want to program to auto-start by default, this can be changed by right-clicking on the icon. In fact, Hot Swap doesn’t come with a window or anything of the sort, it’s all about the icon and what can be done from it.

Overall, we like what Hot Swap has to offer in terms of features and its overall capabilities. We recommend it for anyone who is interested in hot swapping his or her hard disk drive.

Download the Hot Swap tool right now, free from the official website.

How do I know how much swap is used on Windows 7?

Apparently, as per Commit charge is 100% full but physical memory is just 60% when using no page file and http://brandonlive.com/2010/02/21/measuring-memory-usage-in-windows-7/, the Commit numbers in Windows 7 Windows Task Manager include both the physical and the swap memory, and count the virtual memory that has been allocated, but not necessarily has ever been used yet (i.e. not necessarily backed up by any physical source).

As such, is there a way to know the actual swap usage on the system? Simply subtracting physical memory from the Commit numbers won’t work, as it apparently includes this unused-but-allocated space, too.

I mean, Windows 7 is supposedly a modern operating system; surely it must have the functionality to see how much of the swap space is actually presently being utilised, right?

1 Answer 1

The Performance Monitor (perfmon.exe) has counters for the page file usage.

1. Load it up by either running «perfmon» on a command line, or by selecting «Performance Monitor» under Administrative Tools.
2. Expand «Monitoring Tools» in the left column and select «Performance Monitor.»
3. Right-click on the graph to the right and select, «Add Counters.»
4. Scroll down the list of available counters to «Paging File.»
5. Click on the down-arrow icon to the right of «Paging File.»
6. Click on «% Usage» under «Paging File» and then click the «Add» button to put the counter under the «Added counters» list on the right.
7. Click the «OK» button.

The graph will now contain a line for the page file utilization percentage.