More so than Hitman or Far Cry 3, The Elder Scrolls V: Skyrim tends to be platform-bound. That's good news for mid-range mobile graphics processors.
Using the High preset, we still see that increasing resolution has an impact on each GPU, though. The Radeon HD 7670M is fairly playable at 1280x720, though it drops as low as 20 FPS in heavily-wooded areas. The last-gen VLIW5-based chip gets increasingly choppy as you step up to 1600x900 and beyond.
Meanwhile, the Radeon HD 8790M does better at 1920x1080 than the 7670M did at 1280x720. We're comfortable calling all three resolutions playable at this detail level.
The Ultra preset is notably more taxing on graphics hardware. We wouldn't bother trying to enjoy Skyrim on a Radeon HD 7670M-equipped notebook at even 1280x720 using that setting. AMD's Radeon HD 8790M fares better, but still suffers occasional performance dips.