What should we consider when sizing CPUs?

[sandroalvesbras]

Hi,

I have a host with (2) socket, (10) cores per 2.2GHz socket with the following types of VMs: Web Application and SQL Server Always On.

I'm going to buy a new equipment and I'm in doubt below:

- (Option 1): Should I acquire a new host with (2) socket, (20) cores per 2.1 GHz socket
or
- (Option 2): I must acquire a new host with (2) socket, (8) cores per 3.2 GHz socket.

OBS 1: If I decide to use (Option 1), I will have a total of more cores, but a lower GHz capacity and I will also need to acquire more SQL licenses.

OBS 2: If I decide to use (Option 2), I have a smaller total of cores, but a greater GHz capacity and I will not need to change my SQL licensing.

Doubt:

1 - What should I consider regarding the decision? The amount of cores per socket to increase my number of processes (thread) or just the amount of GHz?

Thanks.

[a_p_]

It actually depends on the applications' requirements, i.e. whether it benefits more from additional cores, or higher CPU frequency.
Do you currently have performance issues? How high is the current CPU usage?

André

[sandroalvesbras]

Hi @a_p_ ,

to be honest our environment is very performative with disks (all-flash) and CPU and memory with spare.

I'm referring to some windows web application servers with DotNet, something like 4 vCPU and 16GB.

As far as I can see the web application usage is well balanced between CPU and memory. Unlike the case of SQL that uses a lot of memory, even because of that the virtual machines in the cloud are very much aimed at processing memory with higher rates with a CPU model with this focus from what I read.

This made me look not only at my question, but also at the Intel CPU model if it adheres to good practices, for example: Silver, Gold or Platinum.

Our offers to upgrade:

https://ark.intel.com/content/www/br/en/ark/products/215270/intel-xeon-silver-4316-processor-30m-cac...

https://www.intel.com.br/content/www/br/en/products/sku/215273/intel-xeon-gold-6334-processor-18m-ca...

The database, on the other hand, requires more resources like 14 vCPUs and 180GB of memory and has heavy routines at night that use a lot of CPU.

Our goal is to expand to continue with this "margin to spare" and continue living peacefully.

Our concern is to take the risk of acquiring more GHz and being somehow restricted to the limitation of colors per cpu, even though we know that VMware manages this very well.

Thanks.

[a_p_]

Really not easy to give you an advice.

As a consultant I've seen many environments. In most cases the amount of memory was the limiting factor, but I've also seen environments, where a higher CPU frequency made a huge difference.

From what you explain, I'd probably consider something like the Intel® Xeon® Gold 6326 Processor which comes with 16 cores, and a base frequency of 2.9GHz. Although I assume that you aware of it, please keep in mind that Intel's 3. Generation CPUs use a different memory population than earlier generations. Ensure that you plan with a balanced memory population.

André