BIOS and Overclocking

Historically, it was difficult to overclock your processor on a mainboard from ECS. Most previous products from this company had limited overclocking options, and this policy is quite understandable: overclockers prefer more expensive, full-featured mainboards, rather than low-cost solutions from ECS. ECS 755-A2 should have been different, though. This is the first SiS755-based mainboard and it offers excellent performance and good functionality. However, this fact didn’t change Elitegroup’s approach to designing ECS 755-A2: the overclocker is unlikely to find it an exciting platform for his experiments.

All overclocking options are available in the BIOS Setup based on the Award microcode, in the Frequency/Voltage Control page:

You can’t get lost in the options, they are not that numerous:

• You can adjust the FSB frequency from 200 to 232MHz with 1MHz increment;
• You can change the memory voltage from 2.5 to 2.65V with 0.05V increment.

The FSB frequency range is rather small, and we are not allowed to change the CPU multiplier from the BIOS Setup. On the other hand, these functions are rarely used as currently available Athlon 64 processors seldom speed up to 232MHz FSB or higher and they cannot increase their multiplier at all. What’s more disappointing, you can’t change the Vcore, and this fact greatly limits the mainboard’s overclockability. Besides that, the maximum voltage the mainboard can serve to the memory may not be enough in some situations (many overclocker modules require 2.7V). It would also be nice to have an option of changing the AGP and HyperTransport bus frequencies, but you can’t hope to find it in ECS 755-A2. I guess you agree with me that this mainboard is definitely not for overclocking.

Yet another proof to the point is the fact that ECS 755-A2 cannot lock the frequencies of AGP and PCI buses at their standard values. In other words, these frequencies grow up in proportion to the FSB frequency, like in mainboards on the VIA K8T800 chipset. This fact wouldn’t be that catastrophic, if the controllers integrated into the South Bridge were tolerant to the PCI frequency increase. Practice shows that’s not the case. The SerialATA controller was the most sensitive to the PCI bus frequency and refused to work as soon as we increased the FSB clock-rate from 200 to 205MHz. That is, when the PCI frequency is above 34MHz, the SerialATA controller integrated into the SiS964 cannot recognize hard disk drives. So if you plan to overclock on ECS 755-A2, you’d better stick to Parallel ATA drives. By the way, VIA K8T800 is more robust in this respect: its SerialATA controller loses stability at about 220MHz FSB, or 36.6MHz PCI.