Testing Notes
AGP and PCI Locking
Our first task was to answer the big questio: does the nforce 3 250 chipset lock both the AGP and PCI Bus? In short, the answer is yes.As described earlier the BIOS only enabled us to set the AGP bus speed, there was no mention of PCI. As the SATA RAID is now controlled by the chipset I was unsure whether it had any relationship to the PCI bus. I therefore needed to try and check the PCI bus speed using another method. Two tests came to mind. Firstly Gigabyte's Easytune4 software, a Windows-based application that enables changing front side bus speed, Vcore, DDR bus speed, AGP bus speed and PCI bus speed. Secondly we changed the graphics to an old Matrox PCI card which, from previous experience, hates any increase in bus speed. Once the system was booted with an increased front side bus speed, the Gigabyte software confirmed that both the AGP and PCI bus speeds were locked at 66MHz and 33MHz respectively. The PCI graphics card was also quite happy at all the front side bus speeds we tried, thus proving that the PCI bus is indeed locked.
With the reassurance of a locked PCI bus, the next task was to set about seeing just what the AMD Athlon 64, coupled with the Nforce 3 250 chipset, can do. Overclocking is about taking things one step at a time and gradually building a picture of peak performance. I started by seeing just how far I could take the processor's driven clock, with the processor running at stock voltage. Then the fun really began as I ramped up the voltage and got ready to toast my toes on some hot heatsinks.
