Increasing the AGP clock rate boosts performance but can also lead to problems - see Screenshot H.

Some motherboards permit the AGP clock rate to be increased. Ratchet up the tempo in small steps (see Screenshot H) for the "AGP Frequency" value, and reboot your PC after each incremental change. Test each setting with something like a 3D shoot-em-up game, to see if the system remains stable. Keep at it until signs of instability manifest themselves, then back off to the previous setting.

21. Boost AGP Voltage Levels

Higher clock rates also entail higher power consumption. The following changes provide the graphics card slot on the motherboard with higher input voltage.

The "AGP Voltage" option permits you to boost input voltage in increments of 0.1 volts. Make these changes, however, only when higher AGP clock rates lead to system instability and you feel a need for increased speed.

Warning: In some circumstances, setting voltage levels too high can destroy a graphics card. When boosting input voltage has no effect, be sure to reset the voltage to a lower value, and turn the AGP clock rate down, to be sure you restore your system to steady and stable operation.

22. Activate CPU Cache Levels

Activating the CPU cache at any of Levels 1, 2, or 3 delivers definite performance advantages (see Screenshot I.)

The CPU runs markedly faster than the rest of the motherboard, so it must often wait for data. Speed this process up with help from CPU cache, a form of faster memory that sits between the CPU and system RAM.

Level 1 (L1) cache is very small but is located on the CPU die itself, providing fast, temporary storage for data. Level 2 (L2) cache is significantly bigger and can store entire program elements; when the CPU asks for data that the cache already has, this improves performance because system RAM can't respond to retrieval requests nearly as quickly. Systems that include CPUs with an integrated L2 cache typically also have access to external Level 3 cache memory that speeds the PC still further. Activate all related options that the motherboard (and BIOS) make available to you, as shown in Screenshot I.