Trains from Warsaw to Wrocław

Via P and change there is by far faster-there are indeed still a very few direct (that means no change, not no stops) pociagowe, but most parts of THAT line are so bad and long not maintained the speed is so low that it is what it now is. Partly due to large areas in PL having had coalmining which makes the soil unstable. There is likely also stlill an overite that runs n and mainly brings the holidaymakers to the cool mountains S-W of Wroclaw. (say: vrooch-waf)

It seems you are slowly starting to learn: as always, the planner of the railway conceredn would be nr 1 to try out-and in PL there are also various other sources that overveiw all transport: e-podroznik and others-then you might even see that there are also direct BUSes that can even be faster-the motorways were the first to get upgraded after communism fell.