If you enable HostClk+PCIClk you should see about a 3 to 5 % increase in your performance. You may encounter some instability, if you do you may want to back off this setting. The KT7 memory bus is 200Mhz DDR, the only way to increase it is to over clock the FSB, which will increase you PCI bus frequency as well, but again this can lead to stability issues.
Other improvements can be obtained by setting you CAS to 2 instead of three if your memory supports CAS2.
Lowen