Which is better for gaming and working when it comes to these 2 series? The old classical GTX or the new Tesla? Both are for Nvidia but i wonder which is better for gaming and the other for working.
Tesla cards are almost never a good thing in a home environment. They are usually passively cooled which means you have to have a chassis that was designed for passively cooled cards. Most have no video output of any kind. They are of no benefit for gaming. They can't be combined with a display card.
Tesla cards are for compute only. They are mostly run on command line and I think all of them now don't even have a video port. If you are doing CUDA programing than a Tesla card is a good choice as a add-on, though useless for gaming unless you are the developer.
Tesla cards are almost never a good thing in a home environment. They are usually passively cooled which means you have to have a chassis that was designed for passively cooled cards. Most have no video output of any kind. They are of no benefit for gaming. They can't be combined with a display card.