a 270 crossfire would be good if you have a 270 already if not i would get a 390 or even a 380 would give you very good performance at 1080p
270 crossfire wouldn't be that good in general let alone for VR. No doubt most of these new VR titles coming out probably won't even have proper support for Crossfire anyways. And even the non VR games today that do support Crossfire give you very little performance increase.
A 390 would smash 270 crossfire anyways I'd imagine. That 8gb of VRAM would also certainly come in handy seen how the Vive runs at a resolution of 2160 x 1200.
I wouldn't bother with crossfire unless you had to. If you already have one 270x and can get another one cheap, and have a good enough psu, it would work, but a single more powerful card would be best.
I would say a bigger card. You could crossfire 2 270x's but most likely VR titles won't have proper support for crossfire. Not to mention most games now don't even have crossfire support and the ones that do the performance increase is minimal.
You would also have to deal with the extra heat in your case and fiddling round a bit with Catalyst/crimson to get it to work. Ive tried it with 2 Sapphire 7950's and it just isn't worth it.
Get a 390 or wait for the new Nvidia Pascal GPU's rumored to come out late this year.
a 270 crossfire would be good if you have a 270 already if not i would get a 390 or even a 380 would give you very good performance at 1080p
270 crossfire wouldn't be that good in general let alone for VR. No doubt most of these new VR titles coming out probably won't even have proper support for Crossfire anyways. And even the non VR games today that do support Crossfire give you very little performance increase.
A 390 would smash 270 crossfire anyways I'd imagine. That 8gb of VRAM would also certainly come in handy seen how the Vive runs at a resolution of 2160 x 1200.