AGP 4X : When the CPU is overclocked of more than 5 MHz (10 on some mobo), the BIOS will force the AGP in 2x mode. The tweaker reconfigure the AGP management to 4x, AGP 4x allows a bandwidth of about 1 GB/s

CPC Mask : The CPC ( Command Per Clock ) is an option which brings a speed increase in memory transfer, the BIOS activates sometimes the CPC Mask, which inhibits the CPC in case of overclocking.
DCT : : DRAM cycle time : the DCT enables to specify the minimum amound of time that a memory page must remain open before being closed and opened again. The shorter it is, quickly the data are written into the memory, So it is faster. The default setting is [5T,7T] but always in case of an OC it is set back to [7T,9T], the tweaker forces the DCT to [5T,7T].
DPCP : DRAM Page Closing policy : This item, which can be either "One Bank", or "All Bank" is automatically set to "All Bank" (about 5% slower in memory transfer) in case of overclocking, the tweaker force this item to "One Bank ".

SM Always Bypass : This item enables a gain of some precious NS in the DRAM Latency. Like the others, this setting is disabled in case of overclocking

а) Только соответствующий Асусовский флэшер (если на Асусовской матери; при хот-свапе на других матерях - любой, главное, чтоб флэшку "съел");
б) С бут-блоком...
Остальное (в смысле осторожности, акуратности, чистого ДОСа и пр.) - как обычно...