On Gigabyte GA-P35C-DS3R we could find these overclocking options (F2, May 21st, 2007 BIOS):

• FSB clock: Can be adjusted from 100 to 700 MHz in 1 MHz steps.
• PCI Express clock: Can be adjusted from 90 MHz to 150 MHz in 1 MHz steps.
• CPU voltage: 0.51250 V to 1.60000 V in 0.00625 V increments plus 1.8 V and 2.0 V settings.
• Memory voltage: Normal, +0.1 V to +0.7 V in 0.1 V steps.
• PCI Express voltage: Normal, +0.1 V, +0.2 V and +0.3 V.
• FSB voltage: Normal, +0.1 V, +0.2 V and +0.3 V.
• North bridge voltage: Normal, +0.1 V, +0.2 V and +0.3 V.

This motherboard feature dynamic overclocking, which Gigabyte calls CIA2. Dynamic overclocking allows you to overclock your computer automatically thru a single adjustment on the motherboard setup. You can choose between five overclocking levels: cruise, sports, racing, turbo and full thrust. Our review was done with dynamic overclocking disabled.

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Figure 6: Overclocking adjustments.

This motherboard also provides some memory timings adjustments, as you can see on Figure 7.

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Figure 7: Memory timings settings.

On this motherboard there is no way to lock the memory clock at a specific clock rate, so overclocking the CPU you will automatically overclock the memory as well. This may be a problem as the maximum clock your memories can achieve may limit your overclocking. On the other hand, you can configure the FSB/memory clock ratio, so you may increase this when you think your memories are running at a too high clock.

The PCI Express clock configuration is also very important, as you can lock the PCI Express clock at a given value (100 MHz, for example). Usually when you increase the FSB clock you will automatically increase the PCI Express clock as well, and sometimes your overclocking will be limited not by the CPU but by the devices connected to the PCI Express bus. Thus with this option you can increase the probability of setting a higher overclocking.

The maximum external clock rate we could configure on this motherboard was 324 MHz, what made our memories to run at 972 MHz (FSB/memory ratio of 1:1.5). With this overclocking our Core 2 Duo E6700, which normally runs at 2.66 MHz, was running at 3.24 GHz, an impressive 21.80% increase on its internal clock rate. With this overclocking our system performance increased 17.83% on Quake 4 and 12.05% on PCMark05.

We could configure our external clock above that but the system was unstable. We only consider our overclocking to be successful after we can run at least four times Quake 4 and PCMark05 with no errors.

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Figure 8: Maximum overclocking with Gigabyte GA-P35C-DS3R.

This is a very high overclocking level. So far there is only one motherboard were we could achieve an overclocking higher than this without playing with extra adjustments, ASUS P5N-E SLU (327 MHz). On ASUS P5B Premium Vista Edition we could set our CPU running externally at 323 MHz, on ASUS P5B we could set our CPU running externally at 316 MHz, on MSI P35 Neo Combo we could set our CPU running externally at 314 MHz and on MSI P35 Platinum we could set our CPU running externally at 305 MHz.

We, however, didn’t play with voltage settings or any other fancy adjustments, so you may achieve a better overclocking than we did with more time and patience – on this motherboard and also on the other motherboards we reviewed.