What should I upgrade

[Carz728]

This is my current build. 

PCPartPicker Part List

Type	Item	Price
CPU	Intel Core i5-8400 2.8 GHz 6-Core Processor	$239.99 @ Newegg Canada
CPU Cooler	Cooler Master MasterLiquid ML120R RGB 66.7 CFM Liquid CPU Cooler	$119.99 @ Amazon Canada
Motherboard	MSI Z370 PC PRO ATX LGA1151 Motherboard	$190.81 @ Amazon Canada
Memory	Corsair Vengeance LPX 16 GB (2 x 8 GB) DDR4-2133 Memory	$84.99 @ Canada Computers
Storage	Western Digital Blue 500 GB M.2-2280 Solid State Drive	$79.98 @ Amazon Canada
Storage	Crucial MX500 500 GB M.2-2280 Solid State Drive	$74.98 @ Amazon Canada
Storage	Western Digital Caviar Blue 1 TB 3.5" 7200RPM Internal Hard Drive	$55.50 @ Vuugo
Video Card	Gigabyte Radeon RX VEGA 56 8 GB Video Card
Case	Cooler Master MasterBox NR600 (w/o ODD) ATX Mid Tower Case	$89.78 @ Vuugo
Power Supply	Corsair CX (2017) 550 W 80+ Bronze Certified ATX Power Supply	$54.99 @ Memory Express
Monitor	Asus VG245H 24.0" 1920x1080 75 Hz Monitor	$199.95 @ Best Buy Canada
	Prices include shipping, taxes, rebates, and discounts
	Total (before mail-in rebates)	$1210.96
	Mail-in rebates	-$20.00
	Total	$1190.96
	Generated by PCPartPicker 2019-12-25 14:28 EST-0500

I have some money left over to spend what should I upgrade. I am experiencing cpu bottlenecks in some games like modern warfare ground war and battlefield 5 so I was thinking about upgrading cpu. The prices in canada for a 9700k and 8700k is crazy around 500. Anyone have any other suggestions for a cpu.

[NineEyeRon]

What is all this about 8400 bottlenecks at 1080p?

 

Its a solid CPU for 1080p gaming and is well within acceptable “bottlenecks” for modern GPUs.

[Carz728]

20 minutes ago, NineEyeRon said:

What is all this about 8400 bottlenecks at 1080p.

 

Its a solid CPU for 1080p gaming and is well within acceptable “bottlenecks” for modern GPUs.

I haven't heard anyone else having problems like this with the i5. Is it possible that my 2133mhz ram is affecting CPu usage?