Thanks guys for your reply.

@cellard,

I already visited this website several times but I couldn't find my card listed.

@ranochigo,

Do you mean that cudaminer is not optimized for "Scrypt" mining? as I tried it with GUI-Miner for bitcoin and I got 25-70MH/s depending on the pool.

Hello,

I am using GeForce 840M GPU and Cudaminer 2014-02-28 to mine litecoins.
I tried different configurations for the card but I always get maximum hash rate 40KH/s.

I am using Win7 64-bit with latest drivers from NVidia.

I tried the following settings:
cudaminer.exe -d 840M -o stratum+tcp://litecoinpool.org:8080 -O worker:pass
cudaminer.exe -d 840M -l T5x12 -o stratum+tcp://litecoinpool.org:8080 -O worker:pass
cudaminer.exe -d 840M -l T8x10 -o stratum+tcp://litecoinpool.org:8080 -O worker:pass

Am I doing something wrong here? or this is the maximum of the GeForce 840M card?

Thanks for your help.