OS performance

[abeetha.m]

Of course there are ways
to improve performance by playing with the hardware settings, but there are
also ways of tweaking the Operating System. The OS is very tightly knitted with
the hardware's performance. Tweaking it really helps.




This part of System
Optimization is based on Windows 95. Some may complain, but this OS is simply
the most common. You can find some tips for Windows NT optimization here.




The biggest drawback on
performance that has to do with the OS is virtual memory. This is where the OS
writes to the hard drive when it has run out of space in the RAM. When running
many programs or large programs, the system makes use of this virtual memory,
and performance lags. It causes frequent read/write actions and head movements.
These head movements, or seek time, is the slowest feature of the hard drive.




When storing this
temporary information to the hard drive, it puts it in a swap file. This file
gets larger as Windows 95 needs more room, and smaller as it needs less.
Adjusting the characteristics of the swap file can benefit performance.




You can mess with the
swap file settings in the Control Panel. Click on System, then the Performance
tab. Under Advanced Settings, click Virtual Memory. Here you can set the
minimum and maximum size of the swap file as well as its location. If you set
the minimum and maximum sizes to be the same, it tells Windows that it can't
resize the file. If they are different, it can resize the file within the
limits. The default value is to let Windows do it all, with a 0 min and no max.
When done, hit OK.




Do not set the swap file
size to be too low. If you do, you may get out of memory problems later. And
definitely do not disable the use of a swap file.




The automatic resizing
feature of the swap file under Windows 95 is good for conserving disk space,
but not good for performance. Using Virtual Memory at all reduces performance,
but its even worse when the drive is continually resizing the file. So, if you
have plenty of disk space to spare, give the swap file a set size. In the
virtual memory settings window, set the min and max files to be the same. This
will eliminate resizing.




The size to set it to is
sort of a judgment call. It sort of depends on the kind of work you use your
system for. The typical value is around 50 MB. If you run into problems, you
may want to increase it.




Another method of
improving performance is to optimize the position of the swap file on the hard
disk. Placing it near the front of the drive ensures that the read/write heads
don't have to travel as far. This can be done by using a second hard drive for
the swap file. This gets the read/write action off of the same drive as the OS
and the major programs, and can increase performance. You can also make use of
partitions to do this. You can set off a separate partition for the swap file.
This treats it as its own drive and eliminates some problems. You can also
create two partitions and put the swap file at the beginning of the second,
thus putting the file at the center of the hard disk and minimizing the
distance traveled by the heads.




This partition method can
be used on any files which one wants to increase performance on.




The Windows 95 use of
disk cache can damper performance. Disk cache is what Windows 95 does with data
from the hard drive. It places the most recently used data from the hard drive
into whatever memory is not being used by programs. This serves as a sort of
virtual disk. The intent is to increase performance by minimizing hard disk
activity, but it doesn't always work that way. As activity increases, the
system wants to use this disk cache. This wants more room on memory. Then, as
the programs need more memory for operation, they have to go to virtual memory
because disk cache has taken so much memory up. This leads to a weird situation
where the disk performance increases, but performance decreases anyway due to
the use of virtual memory.




The way around this is to
limit the amount of space the OS is allowed to use for disk cache. You can
choose whatever amount you want taking into consideration how much memory you
have. If you have 32 MB of RAM, a 4 MB limit should be fine.




Unlike adjusting the swap
file size, playing with the disk cache size is not easy. It involves editing
the SYSTEM.INI file in a text editor. Once you
are in the file, find the line that contains "vcache". Right below
this line, insert MinFileCache=x and MaxFileCache=x as separate lines. Replace "x" with the value of min and max in KB. Keep in mind that 1 KB is
actually 1024 bytes. So, in the above 32 MB of memory example, you could insert
MinFileCache=4096 and MaxFileCache=4096 to limit the disk cache size to 4 MB. Like all
changes to Windows, you will have to reboot for the changes to take effect.




Automatic virus scanning
software can really decrease performance. Such programs are always scanning
every file as you open it for viruses. This continual scanning is a drain on
the system. A good virus
scanner is recommended, but not one that is checking files continually.




A few more notes. When
you upgrade hardware and install the drivers, always remove the drivers of the
old hardware if you remove it. A system, over time, can become crammed with
drivers, many outdated, and this just serves to decrease performance. You can
see what hardware and drivers are installed on your system by clicking on
System in the Control Panel. Then click the Device Manager tab. You are given a
list of installed hardware. If you see devices that are no longer on the
system, you should delete them. Be positive they are no longer in use before
performing this step.




Also, get a good
installer program. Over time, after cycling through many different programs on
your system and since deleting them, the system can become clogged with traces
of the old software. Manually deleting some programs is fine, but other dig
themselves into the OS and if you delete them, there are still traces. All
Windows programs create entries in the Windows registry and these entries are
often still there after the program is long gone. This can lead to a long
registry file and it bogs performance. Many good programs exist that uninstall
old software and are quite good at removing every trace. Many programs come
equipped with their own uninstalling program. Still other programs are designed
to clean out Windows registry.

[wizkid]

worthfulinformation..........

[vjsreevs]

awesome !!!!

[yathish]

nice info...............