optimizing performances *

 

The basics of speed
Limiting Windows' usage of disk cache
Handling Windows' virtual memory
Increasing Windows' stability
Overclocking tips
Freeing up IRQs
Boosting the Pentium Pro/Pentium II video chipset
No ISA card = 5% performance boost

 

> Limiting Windows' usage of disk cache

Why modify disk cache?
Windows' management of the disk cache isn't exactly the most efficient method. Basically, it expands the disk cache when file system activity is taking place, and shrinks it when memory is in more demand than the disk. Sounds like a good idea, except for the fact that it will suck up as much memory as it can at some times, fighting with applications for physical RAM.

How it works
For an example, lets say you have a system with 64MB of RAM, and you are copying a 100MB file from one hard drive to another. Windows will expand the disk cache to fill all of available RAM that it can, because it thinks that maybe you'll be reading from that file you just copied. It might make the disk cache take up 10, 20, even 30 to 45MB of RAM. Right now you've got 45MB for disk cache and Windows drivers and Kernel are probably taking up the last 19MB (it happens). What happens when you go to start up a RAM and disk (at least for the initial load) hungry application, such as Photoshop 5.0 or Unreal, after copying that file? Thrash, thrash, thrash goes the hard drive. Windows is very childish in letting up RAM for it's disk cache. I remember on my K6-200, when I upgraded from 32MB to 96MB RAM, Windows was grabbing lots of memory for the disk cache, and I got the dreaded background picture page-in. Windows was hogging so much RAM that my whole 600K background bitmap had to be paged in from disk, which is something I used to get on a 386DX-25 with 4MB RAM in Windows 3.1.

What's next?
The idea is to llimit that disk cache! Basically, you want the minimum amount of disk cache to be about 1MB (you always want some cache present), and the maximum to be about 1/4 of your total memory. Here's a short table for quick reference ...

RAM
8Mb
16Mb
24Mb
32Mb
48Mb
64Mb
96Mb
128Mb
Cache Max.
2048
4096
6144
8192
12288
16384
24576
32768

Procedure
Now, here's what you do to limit your disk cache size

>Windows98 and above: Click Start, Run... then type in msconfig. Validate. Click the system.ini tab.
>Earlier versions: Click Start, Run... then type in notepad c:\windows\system.ini. Validate.

Now find the section called [vcache] which is near the end. Modify it to look like this, substituting your value for the Maximum:

[vcache]
MaxFileCache=32768
MinFileCache=1024

Save the file, close Notepad, and restart your system. And just so you know, "MinFileCache" and "MaxFileCache" have to be greater than zero.

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* The Knights of Boot© disclaim any responsibility for any damage arising as a result of the implementation of these instructions.