Sniper zoom = framerate killer?

[J0hntekk]

Hi,

i'm playing on Win 7 64, GTX 580, I7 2600k 4,3 Ghz
1080p on high settings (textures normal, no hi res shadows etc), 2xMSAA

I'm playing with a controller on locked 30 fps with vsync on half refresh rate (60Hz monitor).
I get 30-120 fps without vsync but i want a locked smooth framerate on good settings.

So 90% of the time everything is fine, no problems in town
but out in the nature there are some parts with problems. Especially with 2xMSAA or shader quality on very high or with high shadows
and most of them happen when i use a sniper rifle with zoom.

There are parts where my framerate drops from 60 and more to 27 (without vsync)
or with half refresh rate 30 fps down to 27.

There is nothing i can do about that other then deactivate MSAA, shader high, grass high, no post fx. Then i can reach 30 fps again.

My GPU usage goes up and down in those parts, like from 90% down to 30 back to 90 and so on every few seconds. Is this a bottleneck thing?

Here are some screenshots from some of the problem parts:
http://s28.postimg.org/rd847cr4b/GTA5_2015_04_20_00_34_33_08.jpg

Zoom to the other site.

http://s15.postimg.org/wsmxv45d5/GTA5_2015_04_20_00_40_19_45.jpg

Zoom or drive through those little forrest parts.

http://s18.postimg.org/ivuhuiz7r/GTA5_2015_04_20_00_44_05_48.jpg

Zoom down the mountain / forrest or play the online heist mission with the 2 trucks.

Is this normal? What is the problem there?

Edited April 20, 2015 by J0hntekk