This season Pro Football Focus has had a lot of good things to say about the Raiders' offensive line. While the run blocking hasn't been consistently great, the pass blocking has been among the best in the league. In fact, PFF rates them the very best in the NFL.
They listed the top five offensive lines by percentage of pressured dropbacks and the Raiders were right at the top
This is even considering the Derek Carr was pressured on 43 of 127 dropbacks (33%) and sacked four times on Sunday. Which I guess says more about how well they were protecting Carr over the first four weeks.