Need help with upgrading gaming PC.

[fcknmrcls]

Hi there! I would like to upgrade my system, most importantly my CPU, but I know I will also have to get a new motherboard. Top priority is running the most recent games at around 60FPS on medium/high settings, so keep that in mind. Please if anybody can help, suggest me the best options I have. My budget is at around $350-$400.
My specs:
Motherboard: ASUS M4A89GTD-PRO/USB3
CPU: AMD Phenom II X4 975 Processor
GPU: Sapphire Radeon R9 280X 3GB Dual-X OC Version
RAM: Corsair Vengeance 12GB (4x3GB) 1600 MHz
HDD: WD Caviar Blue 1TB 7200rpm
Case: Cooler Master CM 690 II Advanced
PSU: 750W
Thanks!

 

[Hawkshot]

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Xeon E3-1231 V3 3.4GHz Quad-Core Processor ($227.99 @ SuperBiiz)
Motherboard: ASRock H97 Anniversary ATX LGA1150 Motherboard ($59.99 @ Newegg)
Storage: Samsung 850 EVO-Series 250GB 2.5" Solid State Drive ($77.99 @ Amazon)
Total: $365.97
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-11-27 10:06 EST-0500

this is going to be your best upgrade path for now, your GPU is still pretty good and is capable of playing most high spec games at high or ultra settings but your CPU and motherboard are really letting you down.

The Xeon 1231 v3 on the same as the I7-4790 just without the integrated GPU which you don't need as you have a dedicated GPU. also if you mirror your OS over to the new SSD your boot speed will increase massively you can also put frequently used games on here to speed up loading speeds

 

[Noldemor]

You should probably go with an AMD core, because i've heard some sayings going on about intel cores dont work so good with amd cards.

 

[fcknmrcls]

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Xeon E3-1231 V3 3.4GHz Quad-Core Processor ($227.99 @ SuperBiiz)
Motherboard: ASRock H97 Anniversary ATX LGA1150 Motherboard ($59.99 @ Newegg)
Storage: Samsung 850 EVO-Series 250GB 2.5" Solid State Drive ($77.99 @ Amazon)
Total: $365.97
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-11-27 10:06 EST-0500

this is going to be your best upgrade path for now, your GPU is still pretty good and is capable of playing most high spec games at high or ultra settings but your CPU and motherboard are really letting you down.

The Xeon 1231 v3 on the same as the I7-4790 just without the integrated GPU which you don't need as you have a dedicated GPU. also if you mirror your OS over to the new SSD your boot speed will increase massively you can also put frequently used games on here to speed up loading speeds

Thank you so much!

 

[Hawkshot]

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Xeon E3-1231 V3 3.4GHz Quad-Core Processor ($227.99 @ SuperBiiz)
Motherboard: ASRock H97 Anniversary ATX LGA1150 Motherboard ($59.99 @ Newegg)
Storage: Samsung 850 EVO-Series 250GB 2.5" Solid State Drive ($77.99 @ Amazon)
Total: $365.97
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-11-27 10:06 EST-0500

this is going to be your best upgrade path for now, your GPU is still pretty good and is capable of playing most high spec games at high or ultra settings but your CPU and motherboard are really letting you down.

The Xeon 1231 v3 on the same as the I7-4790 just without the integrated GPU which you don't need as you have a dedicated GPU. also if you mirror your OS over to the new SSD your boot speed will increase massively you can also put frequently used games on here to speed up loading speeds

Thank you so much!

You're very welcome