MSI GTX 750 Ti 2GB OC - 2700MHz problem/bug

ukLz

Distinguished
Hello, community.
I've got one serious problem.. Recently I bought my new PC.

Specs:
CPU: i5-4460
RAM: 8GB DDR3
GPU: MSI GTX 750 Ti 2GB OC
MOBO: ASUS H81M-R
PSU: Some chinese company - Spire 500W

Problem is that this GPU is OverClocked version and Memory Clock is supposed to be OC'd to 5000MHz as it says here: https://www.msi.com/Graphics-card/N750-2GD5OC.html#hero-specification

http://i.imgur.com/WGvQiVA.png

And since I have exactly same GPU like that one, mine is supposed to be OC'd just like that, right?

But no.. For some reason, my GPU is running on 2700MHz and I can't change it at all..

http://i.imgur.com/sfl3czn.png

I tried to overclock it even more in MSI Afterburner, but then my screen get f*cked up.. I mean, some green and purple dots are appearing on my screen and after few secs it returns back as it used to be normally..

I checked on internet about that and it says that over overclocking GPU is very dangerous and vulnerable for GPU and it may die if I continue doing that..

Since then, I stopped taking any action and came here to seek for help & solution!

So yeah.. Thanks for reading and help me!

EDIT: The reason why I'm even complaining about this is because yesterday I installed Battlefield Hardline and I was running it on ULTRA + 1080p 60Hz and it was supposed to run on 60FPS with small drops down to 50. I checked on youtube benchmark for same those PC specs on same game.. And that guy had constantly 60FPS with ULTRA and 1080p settings.. Then I asked my friend why is that happening? Why do I have less FPS than that guy does.. And he said probably because of my clock of GPU.. It might be because of Memory Clock which is locked to 2700MHz, not to 5000, unfortunately... So yeah.. Please help me!