It depends on the design, whitefire's designs are far more optimized than mine for those specific algo's. It should scale linearly with frequency. So if it's using 306A at 708Mhz, it should use 153A (130W) at 354mhz and that would provide 8.5Gh/s. It is a good idea to provide A/C for these cards. The colder the card the faster it can run.

@whitefire990 Could you reduce core clock to a more reasonable number and provide some feedback? I'm not sure everyone is going to want to run their card at those junction temps. Keep in mind, even with cooling modifications, At those thermal envelopes, someone running their card in an environment 5F warmer than you, even with the same cooling, may have problems.