There are 3 modes that the board can operate in. It can be in plain UMA mode, SIDEPORT mode or UMA+SIDEPORT. UMA+SIDEPORT enable gives the best performance for the integrated graphics.

If SIDEPORT is chosen, the GFX Clk speed can be chosen. The default is 400MHz

If UMA+SIDEPORT is chosen, more options are available.  You can also override the default 500MHz GFX core by raising it to a a maximum of 1023MHz.

UMA Frame buffer size can be set to Auto, 32, 64, 128, 256 or 512MB.

This is the default SIDEPORT graphics memory speed.

GFX Engine Clk is default at 500MHz, it can be upped to 1023MHz. To run at higher GFX CLK, it is better to raise the NB voltage.