it's just impossible imho. it's true that before we had 1920 pixels per eye over 100° and now 3840 pixels over 200° (so we have the same PPD) but before we had resolution at 1440p, now we should be able to push it to true 4k, leading to a considerably more detailed image.
So it's impossible he actually played at true 4k, it rather was 1080 upscaled (no 1080 laptop could even push 4k VR on Project cars anyway)..
Just to be clear, 4k is 44% MORE resolute than 1440p so there is a VAST margin for improving resolution even just for bigscreen or social experiences, but we need to be sure the hmd will be able to run at that resolution, no tricks, no upscaling if asked to. We didn't have any confirmation on this point tho. @xunshu could you answer to this, please?