Abit BX6 (No option to remove CPU locks)
P2-350: Maximum multiplier setting = 3.5 x - - -MHz = Max

Abit BH6 (SEL100/66# option to remove clock multiplier limit)
P2-350: Maximum multiplier setting = 5.0 x - - -MHz = Max

Hot dog Uncle Jessie, that's some serious overclocking potential there! Realize however that the overall maximum MHz level of the CPU itself hasn't been changed at all. For the P2-350 illustrated above, the max that the CPU can handle is still in the range of 433 to 450MHz. Only now with the clock lock removal, the options are increased as to what that P2-350 can be set to.

Abit BX6 (No option to remove CPU locks)
P2-350: Maximum multiplier setting:
3.5 x 112MHz = 392MHz
3.0 x 133MHz = 400MHz
3.5 x 133MHz = Fail (466MHz)

Abit BH6 (SEL100/66# option to remove clock multiplier limit)
P2-350: Maximum multiplier setting:
5.0 x 83MHz = 415MHz
4.0 x 112MHz = 448MHz
4.5 x 100MHz = 450MHz

Suddenly that P2-350 at the current price of $330 doesn't seem to be as poor a choice as it did just a week ago...

Abit didn't stop with simply unlocking the Intel CPU multipliers for the BH6, they decided to really unload on their competition with another Abit-unique feature. What we're referring to is the "124MHz" bus speed option that is now included with the BH6 in its Soft Menu II settings.

Savvy overclockers know that the gap between achieving a successful overclock from a 112MHz FSB to a 133MHz FSB is large. The PCI peripheral speed goes from a stock level of 33MHz at a 100MHz FSB speed, to an unholy 44MHz at the 133MHz FSB speed (133/3 = 44MHz). Even worse, the stock AGP port's speed of 66MHz at the 100MHz FSB speed goes all the way up to an Earth shattering 88MHz, where almost no AGP video card can perform properly, at least in it's 3D mode.

This is due to most 440BX mainboards shipping with a 1/3-clock divider for the PCI bus (100/3 = 33MHz) and a 2/3 clock divider for the AGP bus (100MHz FSB = 66MHz AGP). Luckily Abit decided to include a 1/4 PCI bus speed clock divider with the BH6 (only active when the 133MHz FSB speed is selected).

What this means is that even at the 133MHz FSB setting, the PCI peripherals still operate at a cozy 33MHz (133/4 = 33MHz). The bad news is that Abit did NOT modify the standard AGP 2/3 clock divider, so all AGP cards will be running at the "warp speed" of 88MHz when the FSB speed is set to 133MHz.

In our tests using a Matrox Millennium G200 16MB 2D/3D AGP card, we found that at the 133MHz bus speed (AGP = 88MHz) the 3D acceleration of all games wouldn't function period. This is an identical symptom that we've seen on other overclocked AGP systems using the 133MHz bus speed previously. Thanks to the 1/4 PCI bus speed clock divider of the BH6 however, our PCI-based Adaptec 2940UW SCSI controller and peripherals functioned perfectly at the BH6's 133MHz bus speed, a feat that we've tried with three other boards and have never been able to duplicate due to those boards only supplying the regular 1/3 PCI bus speed clock divider.