Overclocking the FC-PGA Coppermine: Part 2by Anand Lal Shimpi on January 11, 2000 11:49 PM EST
- Posted in
A couple of weeks ago, we took a look at the overclocking possibilities provided to us by Intel’s FC-PGA Pentium III 500E and 550E in Part 1 of our Overclocking the FC-PGA series. In that article we found that the extremely high overclockability of the new FC-PGA CPUs was due to the following reasons:
- The FC-PGA 500E/550E
are virtually identical to the 733MHz Slot-1 counterparts, and thus hitting
733MHz with a 500E/550E shouldn’t be out of the question.
- The 500E/550E are only running at 1.60v, 0.05v down from the default 1.65v of the Slot-1 CPUs. This allows for a bit of breathing room with overclocking since increasing the core voltage to 1.65v is still within the recommended range for the Pentium III’s Coppermine core.
- Since they have such a low clock-multiplier (relative to the Slot-1 Pentium III Es), increasing the FSB setting to 124MHz and beyond provides very realistic overclocked settings unlike the newer Celerons which carry extremely high clock multipliers (i.e. 7.0x/7.5x/8.0x), consequently making the higher FSB settings useless for overclocking purposes.
We also pointed out that through the use of a newer Socket-370 to Slot-1 converter such as Iwill’s Slocket-II or MSI’s 6905Master, the FC-PGA Pentium IIIs would work perfectly fine in most BX boards, offering an excellent upgrade path to users that have faithfully stuck with their BX setups. Unfortunately, staying with your BX setup limits the success you would have at higher FSB settings because of the strain it puts on your AGP graphics card, due to the lack of a ½ AGP clock divider.
This limitation is obviously non-existent with motherboards based on chipsets with official support for the 133MHz FSB as they feature a ½ AGP clock divider (133MHz / 2 = 66MHz = AGP clock specification). The beauty of the ½ AGP clock divider is that it allows FSB settings, such as the 140MHz and 150MHz frequencies, to be taken advantage of, because, even at 150MHz, the AGP bus is only running at 75MHz, which is still within the range of toleration for most AGP cards including the tons of GeForce and TNT2 based cards we’ve tried at the speed.
At 150MHz the only limitations are really the chipset and your memory as the ¼ PCI clock divider keeps the PCI bus at 37.5MHz, which is close enough to the 33MHz specification that most peripherals don’t have a problem with it. This makes the combination of an official 133MHz chipset and the FC-PGA the perfect solution for overclockers that aren’t looking to spend a lot of money on a new Pentium III setup. And thus we have the basis for Part 2 of our ongoing series of Overclocking the FC-PGA CPUs - overclocking FC-PGA using the 133MHz FSB and beyond.