Hi guys,
People have been reaching out to ask wether the CPU cores count mentioned in the recommendations was accurate or not, and why CPU frequency wasn't mentioned.
To dispell any doubt and to add as much detail as possible, I thought it best to add the comments I have to this discussion as well. This posting will be lengthy.
In general, recommendations for components such as CPU, are always based on the CPU offerings currently available on the market, or at the time the recommendation was given.
Therefore, if the recommendation states that the CPU frequency should be at least 2.0GHz, then that would be a 2.0GHz CPU from a current (latest) or from when the recommendation was provided (date) CPU offering.
What this means, as of today, is that the minimum recommended 2.0GHz CPU should be one of the following two options:
Intel Xeon E5-2683 v3
or
AMD Opteron 6370P
The age/architecture/generation of the CPU should not exceed the server life cycle.
Not everyone upgrades their hardware at the end of a server's life cycle. This results in datacenters running older or very old hardware that don't live up to today's minimum system requirements. Sure, these servers can run applications just fine, but they won't perform as expected.
Here's an scenario where an application owner is tasked with finding the right server to run software with the above mentioned CPU requirements:
- The recommendation states that a CPU with a minimum frequency of 2.0GHz is recommended.
- The application owner finds a system that has the following model CPU: Intel Xeon E5450 (3.0GHz)
- The application owner concludes that the available CPU is 1GHz faster than the minimum CPU recommendation, and is therefore more than adequate.
What the application owner failed to do here is take into account the model and version of the 3.0GHz CPU. It might have 1GHz more than a 2.0GHz CPU but that doesn't necessarily mean that it is faster or better performing.
Here's the technical details for the two CPUs:
Intel Xeon E5450 (3.0GHz), Launched Q4 2007
Intel Xeon E5-2683 v3 (2.0GHz), Launched Q3 2014
Benchmark comparison:
Source: PassMark - CPU Performance Comparison
To keep it simple and to avoid having to bore you with technical differences between these two processors, the bottom line and most relevant point is that the E5-2683 v3 is 3x more powerfull than the E5450 and will therefore, in this particular case, perform 3x better than the E5450 CPU.
Now, immagine the E5450 CPU being a host CPU in a hypervisor server (VMware, Hyper-V etc). What more performance, if any, can you expect from the new application server, if it is going to be sharing CPU resources with other application servers that have similar minimum CPU requirements?
Not mentioning CPU speed when providing recommendations:
I mentioned that the age/architecture/generation of a CPU should not exceed that of the server life cycle. If the CPU age/architecture/generation is not older than expected (on average 3 years old) then CPU speed is not that high on the priority list. The reason for this is that available CPU performance offered on newer CPUs is generally better and faster overall than the previous generation CPUs. What required a 3.0GHz CPU in order to perform 7 years ago, can now run on a 1.8GHz CPU and there's still room to scale.
