my pc lags when playing games

[andrewmerry063]

my pc lags when playing games. Intel® Core™ i7-7700K CPU @ 4.20GHz
Threading
1 CPU - 4 Core - 8 Threads
Frequency
4501.08 MHz (45 * 100.02 MHz) - Uncore: 4201 MHz
Multiplier
Current: 45 / Min: 8 / Max: 45
Architecture
Kaby Lake / Stepping: B0 / Technology: 14 nm
CPUID / Ext.
6.E.9 / 6.9E
IA Extensions
MMX, SSE, SSE2, SSE3, SSSE3, SSE4.1, SSE4.2, EM64T, VT-x, AES, AVX, AVX2, FMA3, TSX
Caches
L1D : 32 KB / L2 : 256 KB / L3 : 8192 KB
Caches Assoc.
L1D : 8-way / L2 : 4-way / L3 : 16-way
Microcode
Rev. 0x84 ► Spectre (CVE-2017-5715) Patched ◄
TDP / Vcore
91 Watts / 1.28 Volts
Temperature
43 °C / 109 °F
Type
Retail (Stock Frequency : 4200 MHz)
Cores Frequencies
#00: 4501.08 MHz  #01: 4501.08 MHz  #02: 4501.08 MHz  #03: 4501.08 MHz 
Motherboard
Model
Asus STRIX Z270H GAMING
Socket
Socket 1151 LGA
North Bridge
Intel Kaby Lake rev 05
South Bridge
Intel Z270 rev 00
BIOS
American Megatrends Inc. 1301 (03/14/2018)
Memory (RAM)
Total Size
8192 MB
Type
Single Channel (64 bit) DDR4-SDRAM
Frequency
1200.6 MHz (DDR4-2402) - Ratio 1:18
Timings
16-16-16-39-2 (tCAS-tRC-tRP-tRAS-tCR)
Slot #1 Module
Corsair 8192 MB (DDR4-2400) - XMP 2.0 - P/N: CMK8GX4M1A2400C16
Graphic Card (GPU)
GPU Type
NVIDIA GeForce GTX 1080 (GP104) @ 139 MHz
GPU Brand
ASUSTeK Computer Inc.
GPU Specs
GP104-400 / Process: 16nm / Transistors: 7200M / Die Size: 314 mm² / TDP: 180W
GPU Units
Shader Units: 2560 / Texture Units (TMU): 160 / Render Units (ROP): 64
GPU VRAM
8192 MB GDDR5X 256 bit @ 405 MHz (Micron)
GPU APIs
DirectX 12.0 (12_1) / OpenGL 4.5 / OpenCL 1.2 / Vulkan 1.0
Storage (HDD/SSD)
Model #1 Name
Seagate ST1000DX002-2DV162 (FW: CC41)
Model #1 Capacity
931.5 GiB (~1000 GB)
Model #1 Type
Fixed - Bus: SATA (11)
Display
Screen #1
Dell Computer Dell S2417DG (DELA0E7)
Screen #1 Spec
24 inches (61 cm) / 2560 x 1440 pixels @ 30-144 Hz
Miscellaneous
Windows Version
Microsoft Windows 10 (10.0) Home 64-bit
Windows Subver.
Build 17134
CPU-Z Version
1.86.0 (64 bit)

 

[drivinfast247]

Looks like you have one(1) ram module. I'd get a 2x8gb RAM kit in the fastest speed you can afford.

 

[mgallo848]

You've got a very fast CPU for gaming
You've got a very fast GPU for gaming
You went with only 1 stick of RAM that is usually what people do for budget PC's. Try to find another single stick of RAM (same vendor, same amount of RAM, same speed and timings). If you can't then I would suggest buying 2x8 sticks of RAM to compliment the rest of that system.