SQL processing suddently get slow during the day

Hi there.

I am new to the forum and seeking some advise. I have recently being assigned to manage a site with a huge SQL network. The problem we are experiencing is SQL processing suddently slows down during the course of the day.
The SQL server is running on Windows Server 2012 R2 with 64GB of RAM and 5 Virtual Cores and running on RAID 5 SSDs and 20Gbps network (2x 10Gbps NIC Teaming).
What we did is moved the server to brand new host and since then it has slowed down. All the configuration is exactly the same as it was before.

We did try up the CPU cores and give more memory and even set the host to priorities the resources, but that didnt help.

Is there anything we can do to resolve this issue?

Hope to hear some suggestions soon.

Kind Regards,
Daniel

I would start here:

Getting Help with a Slow Server - Brent Ozar UnlimitedĀ®

Well, to fix this issue, you can follow the below steps:

  1. Temporarily disable firewalls and antivirus, and then try.
  2. Timely check for hardware and software updates.
  3. Ensure your SQL server should be up to date.
    Thanks