OCIA.net has posted their review of the Palit Radeon HD 4870 Sonic Dual Edition Video Card
A quote from the article:
>> Palit Radeon HD 4870 Sonic Dual Edition Video Card Review
Finally we have the Smart Switch, which controls the dual BIOS that Palit has used with this card. In "normal" mode, the card operates at 750 MHz core / 950 MHz memory. When "turbo" mode is engaged, the card is overclocked to 775 MHz core / 1000 MHz memory - talk about user friendly overclocking!
>> Palit Radeon HD 4870 Sonic Dual Edition Video Card Review