Performance tuning is conceptually simple: Find the bottlenecks that slow the system below its maximum speed, and fix them. The details however can be tricky, and not all bottlenecks are equally important.
Each of the suggested changes are for a specific bottleneck, but if that is not the limiting bottleneck, your performance may not visibly change.
Adding memory is a simple, and currently cheap, way to increase overall system performance. In combination with some of the other tuning suggestions, the result could double or more your current performance.
The biggest variables are how much memory you have, and how many application windows you have open while working. The table below gives minimum recommendations based on which version of OS/2 you use.
| OS/2 Version | Applications Open | ||||
| 1 | 2 | 4 | 8 | Many | |
| Warp 4 | 64 | 96 | 128 | 256 | 384 + |
| Warp 3 | 32 | 48 | 96 | 256 | 384 + |
| OS/2 2.x | 16 - 32 | 48 | 96 | 256 | 384 + |
Recommended Minimum MB of Memory
Note:Certain classes of applications require much more memory than the table shows. If you use any of these frequently, then consider a minimum memory to be 128 MB, with 256 MB recommended. If you use two or more of these memory hogs, multiply those sizes by the number of hog applications running at the same time.
Fortunately, with memory prices at a current low of about $35 for 256 MB of PC133 memory, it's easy to recommend that you start with 128 MB and go up from there.
However, for older systems that require EDO or FPM memories which are currently expensive, this is not an cheap option. For those people I recommend you seriously consider buying a new motherboard that handles PC133 or DDR memory, and the new memory. Make sure it will run your current cpu.
This is typically not much more expensive than just buying older memory and the performance boost is quite a bit greater. If you are not comfortable with a DIY approach, check around locally and see if a guru friend could do this for you.
As a final option, there are some reasons to consider buying a new system if you have one that uses EDO or FPM memory. In a family where more than one person wants to use the computer, if you only have one, before or after this Christmas is a good time to shop for a new system.
The lowest cost new desktop will be much faster, and the old system can be used for the other family members.
Some of the default settings in config.sys are not optimal for systems built later than 1995. Before you make any changes, make a backup with this command:
copy config.sys config.bak.sys /vOnce that is done, you can edit config.sys with then os/2 system editor. Here are specific suggestions, but remember, you may choose to do one at a time if you want to see which ones make the biggest change:
If you run the HPFS file system, and you should, the initial setup is too conservative. The Cache and Crecl parameter defaults are set too low. The maximums are "/CACHE:2048 /CRECL:64" which gives you 2 MB of cache and enables loading 64 x 4K chunks of files. For most people, setting /CRECL:32 will make better use of the cache memory. Use "help hpfs.ifs" for details.
Diskcache defaults to "DISKCACHE=D,LW". This setting is primarily for FAT partitions, but the detail info on this implies that it is also used for caching all directories.
This is default size, based on total memory size and Lazy Writes enabled. Diskcache may be up to 14400 KB in size, but this is more than is effective. I have it set to a useful size and it does seem to help. Start with "DISKCACHE=1024,LW" and work up from there. Use "help diskcache" in an OS/2 command line window for details.