what the difference between windows 8 and windows 7 64 bit

Hello!
what the difference between windows 8 64 bit and windows 7 ultimate 64 bit
I'll have proformace problem If I run at GTX 645 NVIDIA , Intel i5-4440 and 6 gb ram 1TB HDD?

This article may help

The Windows XP upgrade question: Windows 7 or Windows 8? | PCWorld

A lot.

broe23 said:

A lot.

Click to expand...

Well, 8/8.1 can be made to look and feel pretty much like 7, plus that way you would get the "under the hood" improvements. This can be achieved by adding a tiny program called Classic Shell.

Define "performance problem", please. Described configuration should operate Windows 8 with no problems, although specific configuration may include some bottlenecks.

windows 8 is now obsolete, but you can get windows 8.1 which actually has a start button. you can treat the start screen like the start menu in windows 7, but it will take some getting used to. if you dont wanna get used to it you can download classic shell which is a start menu, but to me it looks cheezy and fake so i like the new start screen.

overall your performance should not be affected and will probably get better with your specs...
if you play games your framerates should get slightly smoother due to different handling of graphics by the new kernel

Not much, Microsoft itself said so, the only noticeable difference is metro GUI and metro store apps.
Windows 7 is problem free, Windows 8 has problems with drivers, games, applications and so on.
But if you are a games, you do not have a choice, since only Windows 8.1 supports Directx 11.2.

Having or not having DirectX 11.2 is not that big of an issue, IMHO. First you have to have a video card that actually supports it to even use it. Then the game has to actually use those features. There are lots and lots of gamers still running Windows 7 etc. It doesn't rank very high as a reason to move to 8.1, not for me anyway. If your a hard core PC gamer then yes, it factors in, but for the average Joe, not so much. just my 2 cents.