Why can't my desktop run certain games at ultra

[zionic]

Acer-Aspire
ATC-603-EB12
Hi, I have windows 8.1
I7 4790 3.60Ghz
NvidiA gefore GTX 745 4gb
16 ddr3 memory-RAM
Is that enough to run good games like the forest or bf4 at ultra.
I've searched the requirements for the games and it looks like I can run them at high or ultra but I cant without cropping to 20 fps
I've had problems with the forest and some other games trying to run them at ultra but I only get 20-27 fps does anyone know what I can upgrade or tweak to get that problem fixed thanks (I usually use the best screen res I can for my monitor)

 

[rgd1101]

gpu is weak.

 

[TechyInAZ]

Your GTX 745 is not powerful at all. If you want play those games at ultra at 1080P or 1440P, your going to need at least a GTX970 or 980.

 

[zionic]

Your GTX 745 is not powerful at all. If you want play those games at ultra at 1080P or 1440P, your going to need at least a GTX970 or 980.

Hey is there anywhere I could send my pc to get upgraded as I don't want to break anything and have no experience even Though it's so easy thanks

 

[XxDo1xX]

Were you able to get a gtx970 or 980? I have the same system as you and i m wondering if the card will fit in the casing...

 

[TechyInAZ]

Your GTX 745 is not powerful at all. If you want play those games at ultra at 1080P or 1440P, your going to need at least a GTX970 or 980.

Hey is there anywhere I could send my pc to get upgraded as I don't want to break anything and have no experience even Though it's so easy thanks

First off, you need to figure out what the wattage is on your PSU. I can't find the specs for your computer online.