Hi, We are planning to go on with the second generation gold series processors, instead of the 61x gold series. Can you please explain the difference between S4 and S4S scalability capability? Thanks

[baris1]

For instance Intel Xeon Gold 6154 has S4S scalability, but the second generation Intel Xeon Gold 6254 has S4 scalability. As I know this is about the number of UPIs, but i'm not sure. If so, what i'm trying to understand is, while using a CPU pinning design, with 4 socket architecture, for throughput-sensitive systems, can this still cause a performance problem?

[Emeth_O_Intel]

Hi Baris, Thank you so much for contacting us about this concern. The difference between S4S and 4S is the number of QPI-Links. 4S has 2 links per CPU, S4S and S8S have 3. >S prefix: Exists: Scalable (based on the language, I believe this means you can use fewer processors) Missing: Nonscalable (you must have the specified number of processors) >Number: Number of processors (if scalable, this is maximum number of processors; if nonscalable, this is the required number of processors) >S postfix: Stands for "socket" So, for example, S4S is "scalable four socket" and 2S is "nonscalable two socket". Could you please so kind and be more specific on the question about the performance issue? Regards, Emeth O. Intel Customer Support Technician Under Contract to Intel Corporation

[baris1]

Hi Emeth,

Thank you for your concern.

About the performance issue, I see that the second generation Intel Xeon Gold 6254 processor has a 4S scalability. So this means that CPU has 2 UPIs. So in case we use 4 socket architecture, there will be a square cpu design instead of mesh, which means not all the cpu's are directly connected. I was considering if this may cause performance problems.

We use these processors in our NFV infrastructure, to virtualise our tput-sensitive services. We normally dedicate sockets for virtual services, so we do not use UPI links at this level.

But considering the Host Operating System, CPUs are used randomly, so  it can cause a performance loss. I think this is more relevant if i discuss this with the OS vendor, but I just wanted to take your opinion in CPU perspective. Because this seems like a handicap for the second generation Intel Xeon Gold 6254 compared to the older Gold 6154 version.

Best Regards,

Baris Atabay

baris.atabay@turkcell.com.tr

+905332109516

[Emeth_O_Intel]

Hi Baris, Thank you so much for information provided. Let me double check the information, as soon as possible I will get back to you with the outcome in order to provide you the most accurate information on this. Regards, Emeth O. Intel Customer Support Technician Under Contract to Intel Corporation

[JoseH_Intel]

Hello Baris, We received the following answer from our engineering department: "There is no performance difference between a 4S and S4S (scalability) when used in a four socket system. S4S just means that it can be used with a node-controller to expand into a super computer." Let me know if you have further questions. Jose A. Intel Customer Support Technician Under Contract to Intel Corporation

[baris1]

Hi Jose,

It's all clear. Thank you for your Support.

Regards,

Baris A.

[JoseH_Intel]

Hello Baris, It been our pleasure to assist you . We will proceed to mark this thread as resolved. If you have further issues or questions just go ahead and create a new topic. Jose A. Intel Customer Support Technician Under Contract to Intel Corporation