It appears the answer seems to be yes, the GeForce GTX 690 (and probably some other late model NVIDIA cards that can run four monitors) can run two monitors in landscape and one or two in portrait, if you are using desktop extended mode. This is according to NVIDIA and EVGA technical support. Note that ASUA technical support said that you cannot. As far as I can tell none of them actually tried it but presumably NVIDIA knows what they are talking about. So some day when the GTX 690 actually becomes restocked or the price gougers on Amazon aren't charging $2,000 for a $1,000 card I will be able to order one and find out for myself.