About cuda 11.1 dll error

I am a newbie in ML, after installing cuda 11.1 in my computer i have found a DLL error and fail to recognize my display card. I have searched different forum and found out that the error came from cusolver64_11.dll. So I used a older version cusolver64_10.dll and it seems to work well. Later, my friend told me that he fixed the problem in another way and can use cusolver64_11.dll in cuda. but there was a problem that the time of finishing a loop would take longer. Did anyone can tell me that why would this happen (why using cusolver64_11.dll would take longer time than cusolver64_10.dll)?