Some basic realities:
- swap is bad
- disk drive are very slow compared to RAM
- laptop hard drives are slow compared to desktop hard drives
- RAM is very inexpensive these days (1GB for as little as $60 USD)
One tuning possibility is to increase the swappiness of the system, so more gets moved to swap earlier. This will reduce the large transfers and thrashing that occurs when frames are depleted.
Try these settings as a starting point:
echo "0" > /proc/sys/vm/laptop_mode
echo "500" > /proc/sys/vm/dirty_writeback_centisecs
echo "2000" > /proc/sys/vm/dirty_expire_centisecs
echo "20" > /proc/sys/vm/dirty_ratio
echo "80" > /proc/sys/vm/swappiness
No need to reboot; the changes take effect immediately, but need to be reset after a reboot.