My friend has a system with Intel Core 2 Quad Q8200 2.33 GHz! The multiplier can be changed to either 6 or 7! He changed it to 7 and we increased the CPU Host Frequency! No matter how much we changed it so that the overall clock of the CPU can be a little bit or a lot higher than 2.33 GHz, after applying, the system kept lowering the CPU Host Frequency to 333 MHz (333 MHz x 7 = 2.33 GHz)! It seemed as if there was no way to make the CPU clock go higher than its default value! We also increased the voltage, but that didn't help either! We tried changing some other settings from the BIOS as well, but with no luck! I'd appreciate it if someone can give advise on how to make the overclocking of the Q8200 possible!
Im not sure with Intel, But when it clocks lower is it during idle or low usage? Try taxing the CPU out with Prime or a game and see if the clock jump back up, might be a power saving setting in the bios somewhere.
The Q8200 has a locked multiplier. You can't actually overclock it with the multiplier as you can the K series of processors. You physically have to change the FSB frequency to get a higher clock out of it. So basically, here's the methodology of overclocking a locked multiplier chips.
Final frequency is FSB x Multiplier = Frequency
So if you have 100mhz FSB and an 8x multiplier you get
100mhz x 8 = 800Mhz final frequency.
However, you chip is a little different as it runs off the host clock which is just like the FSB.
The actual FSB isn't in the equation but the host clock is and it's just the same method. SO what you have to do is overclock the FSB by adjusting the FSB which in turn changes that host frequency. Now each board is different and their BIOS is different so I can't tell you exactly what to change but if the board has overclocking options; it should be there.
Don't go with anything extreme and do some reading up about it. I don't have a lot of hands on overclocking experience with the C2D line other than my E8400 I had a few years back but only tinkered with it a couple times. I am going to tell you this however, don't start by changing from say 333mhz to 350mhz and expect an instant OMG stable overclock. SLOWLY increase and test the system. If it doesn't boot right and has issues; there's stability problems.
Remember, overclocking a chip can be dangerous and destroy hardware. Especially with tinkering with the FSB of a motherboard as it actually can cause more than just the CPU to become more stressed by the increased speeds. This can include the RAM, HDD Controllers, PCI and PCI-x bus, and other things that run off of the motherboards FSB. That's why I hated clocking with the C2D series. You actually had to have some good hardware to reach decent clock speeds.