Can I play with retail version?

Hello,

I downloaded the Warmane WoW client, but I have a very bad performance - around 5 fps.
With the retail version, when I play official WoW, I have normal performance - around 100 fps.

What goes wrong? Is it possible to alter my official client, so it connects to Deathwing?

Thanks in advance

If your retail client is 3.3.5, then all you gotta do is change the realmlist to connect to warmane. If it's any higher than 3.3.5, then you would have to downgrade or download a new one. But the thing is that FPS doesn't have anything to do with the client. Problem is somewhere else.

your retail version is WoD, Deathwing is based on Wotlk 3.3.5, so no you can't.
the 5 fps is not normal, try to disable all your AddOns or to download again from here https://www.warmane.com/download but this time get "Wotlk old"

I'll download the old client when I get home. Thanks for pointing out there are different versions.