PC Over Clocking Part 4. Cache Memory

The parameters that control the work of the cache memory are generally found in the BIOS Setup menu under BIOS Features Setup, the items in which are explained in more detail below. Usually you can modify the values using the <+> and <−> or the and keys. Enabled/Disabled will enable or disable the option.
CPU Internal Cache/CPU External Cache
Internal/external CPU cache. This parameter allows the external/internal processor cache to work (or disables it). Disabling CPU Internal Cache/CPU External Cache will significantly slow down the whole system. However, this may be necessary if you are using any legacy hardware or software.
CPU L 1 Cache /CPU L 2 Cache
The processor cache of the first/second level. This parameter enables or disables usage of the first/second level CPU cache for the following processors: Pentium Pro, Pentium II, Pentium III, Celeron, AMD-K6-III, and so on. Disabling this option will slow down your system significantly. However, this may be necessary if you are using legacy adapters or legacy software.
CPU L 2 Cache ECC Checking
Uses ECC for the 2nd level cache memory. This parameter enables or disables the level 2 cache memory ECC for those processors built on the architecture using it.
Video Subsystem and Hard Drive
The parameters that control the functioning of the video subsystem, the hard drive, and the system BIOS are usually located in the BIOS Setup menu under BIOS Features Setup and Chipset Features Setup, whose items are described below. Usually you can modify the values using the <+> and < > or the and keys. Enabled/Disabled will enable or disable the option.
Video BIOS Shadow
A "shadow" copy of the video ROM.
This parameter enables or disables creation of a „shadow” copy of the video BIOS in the RAM. When this setting is enabled, the contents of video BIOS will be copied into the RAM, and RAM will actually be used when formally accessing video BIOS. This allows a gain in performance, because working with RAM is obviously much faster than working with RAM.
Video BIOS Cacheable
This parameter enables or disables caching the video BIOS. Caching increases the speed of the video output.
System BIOS Shadow
This parameter enables or disables creation of a copy of the System BIOS in the RAM. When enabled, a copy of the system BIOS will be created in RAM, and all actual work will be done using this copy (while formally working with the system BIOS). The performance increase is due to the fact that RAM access is much faster than ROM access.
System BIOS cacheable
This parameter enables or disables caching the system BIOS. Caching increases the speed at which the system BIOS commands are executed.
AGB Aperture Size (MB)
This parameter specifies the size of RAM allocated to AGP video adapters. The parameter ranges from 4 to 256 MB. Memory is allocated dynamically, within the limits set by the values specified. The remaining part of the allocated memory can be used by the operating system.
AGP/CLK
This parameter sets the AGP clock frequency, which depends on the divider value and operative frequence of the CPU bus (FSB). When setting this parameter, you'll have two options: 1 (1/1, i.e., AGP clock frequency is the same as CPU clock) or 2/3 (i. e., AGP is at 2/3 of the CPU external clock).
IDE HDD Block Mode
Enabling this option will set a block data transfer mode for the hard drive, which will transfer data in blocks. This increases the speed of data exchange and, accordingly, boosts the performance of the disk subsystem.