tanks for your help guys,
but still want to know if it is better to make a min /max files of maybe 500mb or let the os choose the size.
some people think it is nonsens to create a swap file in ram , well i have lots of programs that use the swap file even with 384mb . also i use the ram disk , with is about of 128 mb as a temp dir , so that the garbage of installation programs and all other files with the os puts in the temp will be deleted after reboot - the installaion of programms is also much quicker , cause packed files will be unzipped in meomory ..