Here's a screenshot of the Font Caching section of PalmTweak :-

As you can see, you can choose any arbitrary number as the size of the Font Cache. The default, for my Casio E-115, was 8192 bytes. The 10,104,832 bytes shown above is the total allocated program memory. This includes both free and in-use memory and will vary according to the amount of RAM allocated for program usage by the Pocket PC.

In short, forget the 10,104,832 or whatever number you see. It just tells you just how much RAM has been allocated for program use by the Pocket PC. The maximum size of the Font Cache is exactly what you type in the box. The larger the font cache, the faster your Pocket PC will be able to draw those fonts.

However, the effect produced by increased caching is limited by the total size of fonts that actually need be cached. If all the fonts that are frequently used in the Pocket PC are, for example, only 30KB in size; then there's little use in increasing the size of the font cache to 40KB or more. Therefore, the next question would be what's the optimal size for the font cache?