Disappointed in new A51 why is it SO SLOW?

This is probably my 5-6th dell.  It came yesterday...  So far ITS SLOW AS A DOG.  I got it to replace my iMac (2012) for games and it doesn't begin to run games as fast as the Mac with bootcamp and win7.

It was suppose to come factory over clocked.  ITS NOT.

I have NO IDEA how to over clock to the 3.8 it said I purchased.

There was NO MANUAL and there are no instructions for over clocking or using the Alienware software.

Surely it's easy to change colors but I'm talking about important info.

How come when I run a game or graphics demo it's SLOW like I see each frame?  even off a downloaded windows store game?

I have 150+ steam games on my Mac and wanted to be able to run max (instead of medium) options on the newest games.  This thing is so frustrating... as is windows10.  I hate it as much as 8 and all the previous versions.  I thought this was the  "we're embarrassed so we're giving you 10 done right?"

Processor is i7 3.30 (said 3.8) in store, graphics are Nvidia GTX 980.  SSD/2TB basic drives as I have a lot from the Mac and my old Dell XPS to move over.  I have to tell you - (Mac rules) never thought I'd say that as I've been a PC since 1980 and only sampled iMac 2 years ago.  Was this a51 a mistake?

Ron in Michigan