Stock, skyrim uses only two cores, try adding the following lines in the Skyrim.ini and SkyrimPrefs.ini. (i also use my Toshiba for Skyrim sometimes, and since adding these lines, i get 5-15 Fps more than i did before. My friend has a crap GPU, but a good quadcore pc, and after modifying his ini-s, he was able to play skyrim on low-med settings on his old computer (even though its technically impossible).
Spoiler
In Documents/My Games/Skyrim/
In Skyrim.ini Add/Edit:
[BackgroundLoad]
bBackgroundLoadLipFiles=1
bLoadBackgroundFaceGen=1
bUseMultiThreadedFaceGen=1
bBackgroundCellLoads=1
bLoadHelmetsInBackground=1
bUseMultiThreadedTrees=1
bUseBackgroundFileLoader=1
[Animation]
bMultiThreadBoneUpdate=1
[HAVOK]
iNumThreads=XX
[General]
bUseThreadedTempEffects=1
bUseThreadedParticleSystem=1
bMultiThreadMovement=1
bUseThreadedMorpher=1
[Decals]
bDecalMultithreaded=1
In SkyrimPrefs.ini Add/Edit:
[Navmesh]
bUseThreadedMeshes=1
[Trees]
bUseMultiThreadedTrees=1
bShadowMaskZPrePass=1
[BackgroundLoad]
bBackgroundLoadLipFiles=1
bLoadBackgroundFaceGen=1
bUseMultiThreadedFaceGen=1
bBackgroundCellLoads=1
bLoadHelmetsInBackground=1
bUseMultiThreadedTrees=1
[General]
bUseThreadedParticleSystem=1
bUseThreadedBlood=1
bUseThreadedMorpher=1
bUseThreadedTempEffects=1
bUseThreadedTextures=1
bUseThreadedMeshes=1
bUseThreadedLOD=1
bUseThreadedAI=1
bUseThreadedMorpher=1
[Decals]
bDecalMultithreaded=1
For "iNumThreads" set this to the number of CPU cores your PC has. If you have 4 or more leave this as 5 (maximum).