Dell has a tendancy to underclock its cards (save for the higher end ones). I really don't know why, as all its really doing is robbing people of performance that they COULD have... However, it's likely safer on Dell's part if cards are very conservatively clocked for the mainstream market as there's less likely a chance of failure due to aggressive clock speeds. For the higher end XPS, well, those are for a special crowd, the gamers, and can deal with more failures I suppose...