How A Hard Disk Can Affect Windows Xp Performance.

As your PC gets older and older and you install more programs and information your PC gets progressively slower and slower. One reason could be because your hard disk is becoming increasingly active. This hard disk activity may be in plenty of cases, unnecessary, often being caused by programs and the method causing windows hard disk thrashing. I will show you how to decide where this activity is occurring and who is causing it.

Most people think that hard disk corruption or lack of disk space is the main cause of most method performance issues, but disk time and activity is as much a performance factor. Disk time is a percentage of time that the hard disk is in use. If the hard disk is running at 80 percent of the time, you can be sure that PC performance being affected.

One other thing to think about is the average disk queue length. This refers to the number of processes that are waiting to make use of the hard disk. Using the disk time percentage and the disk queue length will tell you how much the hard disk is being used and also if heavy usage is causing a controversy. If for example the disk time is running at 40 percent and the average disk queue length is two or less, then your hard disk is maintaining with the requests for access.

If the percentage of disk time is above 80 percent and the average disk queue length is two or more, it means that you PC processes are waiting for the hard disk to become available. If a method has to wait for any part to become available you will experience a drop in performance of your PC.

To decide in the event you have a windows hard disk thrashing issue, you need to measure the percentage of disk time and the average disk queue length.

Before you start this procedure you ought to perform a full disk defragmentation on all of your hard disk partitions. This will be sure that all the files are contiguous and that the hard disk can perform optimum reads and writes of the files.

After you have performed the defragmentation run the Performance Monitor utility by going to

Start > Control Panel > Administrative Tools and then Performance.

When the Performance Monitor opens there may be some monitor counters already running, (shown at bottom right), click on each in turn and then delete to remove them. As each counter makes use of some resources it is best to have as few running as feasible to make the measurements more correct.

In the Performance Monitor window perform the following:

* Click the + icon to open the Add Counters box.

* Click on the Performance Object dropdown list and choose PhysicalDisk. This will bring up a list of physical disk counters.

* Select the %Disk Time counter from the list and click the All Instances button. This will be sure the method will measure the performance of all the hard drives.

* Click the Add button to add the counter to the Monitor.

* Select Avg. Disk Queue Length from the counter list, and again the All Instances button. Click the Add button then the Close button. The performance monitor will then start analyzing the disk usage.

Taking a look at the monitor results, you can see that the lines shown on the graph correspond to the counters that you have selected. The pink line is the average disk queue length for the drives C: and D: which are in this case partitions on hard drive Zero. A more correct value can be obtained by selecting the counter that you need to see in more detail.

So how do you track down the method that is using all the disk resources? The first thing you need to do is raise the Windows Task Manager. You can do this by pressing -

[Ctrl][Alt][Delete]

on your keyboard holding each down in turn. The Windows task manager shows you the utilization of resources that all the processes running in the method use.
Windows task manager usually has some monitor counters selected as standard but disk usage may not be one of the them. You can select which counter you need to see as follows:

* Click on the "Processes" tab at the top. This will show a list of processes that are running on your PC.

* Click on "View" in the menu at the top then on the "Select Columns".

* In the window that comes up deselect everything then select "I/O Read bytes" and "I/O Write Bytes" then "OK"

You ought to now look to see if any of the counters against the processes are changing at a fast rate. The counters ought to only change occasionally or not at all. In the event you see one that is constantly changing, then that the method may be the one that is hogging your PC's disk resources.

To kill a method that is hogging a resource, right click on the method and then select "End Process" in the menu that appears.

If the particular method is a part of the Windows XP operating method, there is a lovely chance that the high disk usage is caused by thrashing. High disk usage can be caused by "swapping and thrashing"

When the method moves memory blocks between physical and virtual memory (normally called Paging) this is swapping. This is a standard method in Windows XP. Virtual memory is space used on hard disk and as additional memory. This is completed when another method requires "Real" memory and there is not empty space in actual memory to place it. In this case the method will put a method that is in actual memory down to the paging file on disk to generate the space.

Windows hard disk thrashing is caused by high actual physical and virtual memory swapping. This is one reason why it is recommended that as much actual memory be installed on your PC as feasible.

However, if the disk usage is traced to a non-Windows method, then you may have issues with an individual service/program.

In the event you eliminate a method you feel is causing excessive disk usage, processor time and memory will even be affected.

You can now see the way you can track and identify a program or method that may be causing excessive disk time usage and the way it degrades the method. Using the Performance Monitor to measure both disk time and average queue length, you can see if the hard disk is being excessively used by the system's processes. Using the Widows Task Manager you can further decide which method that may be causing the issue.