Kernel on GT 740 run slower than GT 430

First, sorry for writing. I’m brazilian and I do not write very well.
I upgrade my gpu (GT 740). Previously, on GT 430 the kernel of my project run much faster. Both gpus have DDR3. I use VS 2013. Additionally, GT 430 has 96 cuda cores and 1 GB of RAM and GT 740 has 384 cuda cores and 1 GB of RAM.

On GT 430, I compile the project with compute_20,sm_20 and configure the threads and blocks size to 192xNxM.
On GT 740, I compile the project with compute_30,sm_30 and configure the threads and blocks size to 384xTxS.
In both case, I clean the project. My CPU is a I5-2320 with 4 GB of RAM.

Thanks.

You have not told us anything about the nature of your code, or the actual timing data. So we cannot even guess as to what might be the source of your observations. Do you build your code as a release build in both cases? How are you measuring the elapsed time? What happens if you use identical thread block configurations for both GPUs?

If your application is memory bandwidth limited, no speedup should be expected, since the two GPUs have identical memory throughput with DDR3:

http://www.geforce.com/hardware/desktop-gpus/geforce-gt-430/specifications
Memory Bandwidth (GB/sec) 25.6 - 28.8

http://www.geforce.com/hardware/desktop-gpus/geforce-gt-740/specifications
Memory Bandwidth (GB/sec) 28.8