CPU usage and ram usage issue cyberpanel

i am using 12 core cpu , 48gb ram server.

most of the time CPU load is fine but suddenly sometimes CPU usage and ram usage seem to be full.

how can my 4 sites use 48GB ram?

my php memory limit is 512mb
virtual host Max Connections * 15
LSAPI_CHILDREN=15
Memory Soft Limit (bytes) 3047
Memory Hard Limit (bytes) 4047M

Process Soft Limit 600
Process Hard Limit 800

LiteSpeed tuning setting https://prnt.sc/13vf45s

Php tuning setting https://prnt.sc/13vfblu

error log error log cyberpanel - TextBin

brother, can you please tell me where is wrong, my site has heavy traffic around 300/400 / sec

daily 90k/100k+ traffic. help me please