render time 4 times slower

after updating to 10.2 thing gotten worse for me with regular beach ball
and i hope problem will be solved after update 10.2.1 but thing gotten more worse my render time slowed 4 times compared to previous
is there anything i can do to solve this
in between i created another user to test how my old 10.1.4 is working and it works fine as slow render problem followed
Please suggest me what to do now

I would test 10.2 or 10.2.1 with a different user, and/or 10.1.4 on your regular account.
The fact that 10.1.4 running under a different user is ok does not tell if the problem is due to FCX version or user account.

fb_100001184235824 wrote: ...after update 10.2.1 but thing gotten more worse my render time slowed 4 times compared to previous...

By render I assume you mean export to a file. It is suspicious that 4x-5x is roughly the performance difference between using Quick Sync and not. Is it possible you are exporting H.264 on an iMac and one is using "Faster Encode" and the other "Better Quality"? On my 2013 iMac I don't notice dramatically slower H.264 exports using 10.2.1 -- provided I am using the expected settings.

If it is H.264 on an iMac I suggest you try both export quality settings on both versions of FCP X and see if that's the issue. If it's a Mac Pro this does not apply since they don't have Quick Sync.