Epson EL 486UC - Manual (Page 35)

Your computer can access RAM faster than ROM. The options
on this screen allow your system to copy the contents of its
system and/ or video ROM into RAM. When you use
shadowing, your system can perform certain operations faster,
providing a significant increase in performance.
Note
For the best system performance, always set the System
shadow and the Video shadow options to Enabled.
If you enable shadowing for specific blocks, the ROM located in
these blocks is copied to the shadow area.
Configuring Chipset Registers
The system can set your Advanced Chipset Control
options or you can manually change the values in the chipset
registers. Setting these values correctly increases your system
performance; however, setting them incorrectly may cause
your system to malfunction or shut down. Be sure to set the
Auto Configuration option to Enabled to let the system
automatically configure these options to avoid problems.
Running the SETUP Program 2-7