On ECS P35T-A we could find these overclocking options (June 12th, 2007 BIOS):

• FSB clock: Can be adjusted from 266 to 500 MHz in 1 MHz steps.
• CPU voltage: Normal or 1.10 V to 1.50 V in 0.05 V increments.
• Memory voltage: 1.85 V, 1.90 V, 1.95 V and 2.00 V.
• North bridge voltage: +0%, +4%, 8% and +12%.

This motherboard also provides some memory timings adjustments, as you can see on Figure 4.

click to enlarge
Figure 4: Memory timings settings.

ECS has never been famous for its overclocking support and on P35T-A we can see two major problems besides the fact that we can’t set our memories above 800 MHz: it doesn’t allow to lock or configure the PCI Express clock (so 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) and its memory voltage setting goes only up to 2 V, while some overclock-oriented memories are usually configured with higher voltages such as 2.1 V or 2.3 V.

The maximum external clock rate we could configure on this motherboard was 307 MHz, what made our memories to run at 921 MHz. With this overclocking our Core 2 Duo E6700, which normally runs at 2.66 MHz, was running at 3.07 GHz, a 15.41% increase on its internal clock rate. With this overclocking our system performance increased 9% on Quake 4 and 8.40% 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.

We could set a higher overclocking with almost all other motherboards we reviewed recently: on ASUS P5N-E SLU we could set our CPU running externally at 327 MHz, on Gigabyte GA-P35C-DS3R we could set our CPU running externally at 324 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 and on MSI P35 Neo Combo we could set our CPU running externally at 314 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.