Core Duo T2600 Overclocking Experiment
For our experiments we took the same Intel Core Duo T2600 processor as the one we used to test our Viiv platform.
This CPU works at 2.16GHz nominal clock speed and 13x clock frequency multiplier. So, this processor uses 166MHz front side bus (667MHz if we recalculate it into the terms of Quad Pumped Bus). This frequency is standard for all mobile processors from Core Duo and Core Solo families. As far as the Vcore of our processor is concerned, it equaled 1.25V, although this parameter may vary between 1.25V and 1.4V by different Yonah based CPU models.
Since the clock frequency multiplier of Core Duo processor is locked, no wonder we had to overclock it by raising the FSB frequency. Luckily, AOpen i975Xa-YDG mainboard offers the following options:
The complete set of overclocking friendly options offered by our mainboard is the following:
- The frequency of the clock generator forming the CPU frequency can be adjusted from 133 to 320MHz with 1MHz increment;
- The PCI Express bus frequency can be manually adjusted between 100 and 160MHz with 1MHz increment;
- The CPU voltage can be adjusted manually between 0.7375V and 1.5V with 0.0125V increment;
- The voltage on DDR2 SDRAM can be set anywhere between 1.8V and 2.15V with 0.05V increment;
- The chipset voltage can be raised from the nominal 1.5V to 1.675V with 0.05V increment;
- The PCI Express bus voltage can also be adjusted between 1.5V and 1.7V with 0.025V increment.
At first glance it looks like AOpen i975Xa-YDG mainboard doesn’t offer than many overclocking-friendly options. However, these options are more than enough for successful overclocking experiments in most cases. The ability to set high FSB frequencies as well as sufficient intervals for Vcore and Vmem adjustment are the most important tools here. The availability and quality implementation of these functions are crucial for successful CPU overclocking and from this prospective AOpen have done a good job. We can only complain about the maximum supported Vcore, because in our case it was the factor that prevented our overclocking from going any further.
The 166MHz front side bus frequency of the Core Duo and Core Solo processors is not typical of desktops. Contemporary desktop platforms have their FSB working at slightly different frequencies: 133, 200 and 266MHz. Nevertheless, AOpen i975Xa-YDG based on i975X chipset for desktop PCs copes just fine with the 166MHz FSB. As for overclocking, we can raise the FSB frequency from 166MHz up to 200MHz without any problems in the Frequency menu of the Voltage Control BIOS Setup.