The more RAM (chip memory) you have in your computer, the faster it will run and the more it can store. As it is working, each program needs to store results in memory. A word list of over 80,000 entries, representing over 4 million words of text, will take up roughly 3 Megabytes of memory. (In Finnish it would be much more.) When memory is low, Windows will attempt to find room by putting some results in temporary storage on your hard disk. If this happens, you'll probably hear a lot of clicking as it puts data onto the disk and then reads it off again. You will probably hear some clicking anyway as most of the programs in WordSmith Tools access your original texts from the hard disk, but a constant barrage of thrashing shows you've reached your machine's natural limits.
You can find out how much storage you have available even in the middle of a process, by pressing F9 (the About option in the main Help menu of each program). The first line states the RAM availability. The other figures supplied concern Windows system resources: they should not be a problem but if they do go below about 20% you should save results, exit Windows and re-enter.
Theoretically, word lists and key word lists can contain up to 2,147,483,647 separate entries. Each of these words can have appeared in your texts up to 2,147,483,647 times. (This strange number 2,147,483,647, half of 2 to the power 32, is the largest signed integer which can be stored in 32 bits and is also called 2 Gigabytes.) You are not likely to reach this theoretical limit: for the item the to have occurred 2,147,483,647 times in your texts, you would have processed about 30 thousand million words (1 CD-ROM, containing only plain text, can hold about 100 million words so this number represents some 300 CD-ROMs.) You would have run out of RAM long before this.
If you have a Gigabyte of RAM or more you should be able to have a copy of a word-list based on millions of words of text, and at the same time have a powerful word-processor and a text file in memory.
See also: speed