Need help choosing components to upgrade my boy's computer

[bssage]

Hello.  I posted and got a lot of help around December then went a differnt way for his gift.  He still wants to upgrade for his Bday.  I would like to keep a budget around $300 could go as high as 4 but I would rather not.  He want to make his more of a "Gamer"..This is the system we are building on.

Sons computer.  The one I would like to upgrade.

Moniter specs:


Acer
Model
S275HL bmii (UM.HS5AA.001)
Cabinet Color
Black

Display
Screen Size
27"
LED Backlight
Yes
Widescreen
Yes
Recommended Resolution
1920 x 1080
Refresh Rate
60Hz
Viewing Angle
178° (H) / 178° (V)
Pixel Pitch
0.3114mm
Display Colors
16.7 Million
Brightness
250 cd/m2
Contrast Ratio
ACM 100,000,000:1 (1000:1)
Response Time
6ms (GTG)
Panel
IPS

Connectivity
Input Video Compatibility
Analog RGB, Digital
Connectors
D-sub, HDMI
D-Sub
1
DVI
No
HDMI
2
DisplayPort
No

Power
Complies with
ENERGY STAR
Power Supply
100 - 240 VAC, 50/60Hz
Power Consumption
Energystar Off (typ.): 0.5W
Energystar Sleep (typ.): 0.5W
Energystar On (typ.): 36W

Computer specs:
HP ENVY h8-1540t
Operating System
Windows 8 Professional (64-bit)
DISPLAY
Monitor
No
Monitor Features
N/A
MOTHERBOARD
Chipset
Intel X79 Express
RAM
RAM Type
DDR3 SODIMM
RAM Capacity
10 GB
Preloaded Memory
DDR3-1333
PROCESSOR
Processor Model
Intel Core-i7 3820
Processor Type
Quad Core
Frequency
3.6 GHz
Cache
10.0 MB
HARD DRIVE
Interface
SATA
Memory Storage
2000 GB
RPM
7200
GRAPHICS
Video Card
GeForce GT 640
Sound Card
Integrated
COMMUNICATIONS
Wi-Fi
Yes (Type: 802.11b/g/n)
Bluetooth
No
Infrared
No
Card Reader
No
Modem
No
More Connections
PCI Express: 3
STURCTURE
Casing
Tower
Dimensions (WxHxD)
6.88 in x 16.22 in x 16.34 in
Color
Black
OTHER
Optical Drive
SuperMulti DVD Burner
Power Supply
460 W
Ports
15-in-1 multimedia card reader + Top I/O (2 USB 3.0 + 1 headphone jack + 1 microphone jack) + Front I/O (2 USB 2.0)
Camera
No
Microphone
Yes
Accessories
USB standard Keyboard, Mouse, TV Tuner


Thanks in advance
Bryan

[camerongray]

The key thing that stands out is that while that machine has an extremely powerful CPU, the graphics card is pretty low end.  I'd highly recommend upgrading this with a GTX 960 or 970 as this would drastically improve the gaming performance.

The only tricky thing with this video card is that you may need to upgrade your power supply to power it.  Would you be able to let us know the make and model of the PSU in the machine currently - There will be a sticker somewhere on it inside the PC with a model number.

[Geek-9pm]

Camerongray,
Doing an upgrade on this computer will not be easy.

You might consider buying a newer unit and selling the old computer. 

[BC_Programmer]

Doing an upgrade on this computer will not be easy.

Replacing the 640GT would not be difficult. I find it unlikely that they could find a new unit within the price range they specified that is equivalent to the system they have now, let alone better.

[bssage]

I know the power supply is not enough.  The last time I asked this was recommended http://www.newegg.com/Product/Product.aspx?Item=N82E16817207013&cm_re=xfx_550w-_-17-207-013-_-Product  Still OK???

I think the last time I had this discussion there may have been some concern about cooling?? 

Let me know If that PSU and the 960/70 is all I need???