Intel P45 desktop chipset
Makes life more difficult for overclockers
4th September 2008 11:22 GMT
We’ve worked with a number of P45 motherboards and have come to the conclusion that it is more sophisticated than P35, which manifests itself in some re-jigging within the Bios that takes effect when you overclock your PC.
With P35, it was a doddle to overclock your Core 2 processor as you could crank up the FSB until it got flaky then you’d raise the CPU core voltage by 0.1-0.2V and pump about 0.4V extra into the northbridge and CPU VTT settings. That would sort out the stability and allow you to raise clock speeds further without any risk of damage to the processor or motherboard, which is pretty much the ideal situation. With P35 you need to increase voltage to keep the clock wave signals strong to maintain system stability. As the clock speeds increase the waves become less precise but more voltage rectifies the situation.
PCMark05 Results

Longer bars are better
With P45 it’s a completely different situation due, we presume, to the new 65nm fabrication process. You no longer need to increase voltages to maintain strong wave signals and it has become necessary to keep the northbridge voltage as low as possible to keep your PC running properly.


Intel Core i7 I7-920 Quad Core Processor (2.66GHz, 4x256kB, 4.8GT/s QPI, LGA 1336 Socket B)
AMD Phenom II X4 965 Black Edition Quad Core Processor (3.4GHz, 6MB L3 Cache, 4x512KB L2 Cache, 2000 MHz Bus, Socket AM3)
Asus P7P55D Motherboard (Intel Socket H LGA1156, P55 Express, ATX, 16GB DDR3)
Intel Core i5 750 Qaud Core Processor (2.66GHz, 8MB L3 Cache, 2.5 GT/s Bus, Socket H LGA1156)
Asus M4A785TD-V EVO AMD 785G/SB710 Socket AM3 ATX Motherboard