BX Outclocked: Solano Shows Its Potential
The most significant characteristic of high performance computers is a fast system speed. This external clock speed (currently 133 MHz) is crucial for best overall performance still today. Some months ago, we had a
Naturally I wanted to determine the performance benefit at 166 MHz Front Side Bus. So far there is no 815-166 (see picture). However, modern mainboards like the Asus CUSL2 support several clock speeds beyond the specified 133 MHz.
Maybe you are disappointed to hear that speeds faster than 166 MHz are not really possible today. Even with highest quality memory modules it is virtually impossible to run the system bus at any higher clock speed.
In contrast to the aged BX chipset, Intel's 815 has been designed for 133 MHz operation. As a result it comprehends all dividers in order to run the AGP within the specs (66 MHz). Remember that both the PCI and the AGP clock are derivated from the system clock speed. As the BX is approved for 100 MHz max, it only knows the dividers 1/1 and 2/3 (for 66 resp. 100 MHz FSB). Overclocked to 133 MHz, the AGP will run at 89 MHz - too much for many graphics cards!
This issue it even more critical at 150 MHz system speed: In this case, your graphics card has to endure 100 MHz (!) AGP speed, which is merely tolerated by GeForce models so far.
The Solano does not suffer from such problems, as the AGP speed does "only" reach 83 MHz even at 166 MHz system clock speed (divider 1/2). According to our experience, this is no problem for the majority of today's AGP graphics cards.