Small foilage lags hard

I also posted this on answerhub but got no answer

So I have made a quite small foilage map which you can see whole map in the players view meaning its small here is how it looks like:

http://m.imgur.com/drjhWIL

it lags less in the editor
hardware specs:
Intel(R) Core™i7- 3632QM CPU 2.2ghz 8gb ram x64bit AMD Radeon HD 7500M/7600M Series
Any Idea why this happens?

You’re massively bottlenecked by you GPU, I’m assuming this is on a Laptop though? Not much you can do about it unfortunately, foliage is overdraw heavy and while most modern GPU’s “laugh in the face of overdraw”, older / less powerful ones just can’t cope.

Also, put r.ViewMode ShaderComplexity into the console and post the results.