I have the same problem.
For example: When I enter in a default freeroam server, in MTA 1.05, I have 35-38 FPS, and with MTA 1.1 I have 19-38 (without shaders).
My computer's specs:
-AMD Athlon 64 X2 Dual Core Processor 4400+ 2.30 GHz
-3 GB RAM
-ATI Radeon 2100
It also crashes more times and sometimes the MTA closes (Microsoft Runtime error) without reason.