Memory speed for 5th gen xeon 8558 with 2 dimms per channel?

[cagey]

Hi,

What speed memory needs to be installed with a 5th gen xeon 8558 with 2 dimms per channel (i.e. 16 dimms)?   One vendor is telling me it needs PC5-5600 the other says PC5-4800 will be fine as it'll only run at PC5-4400 anyway.  The processor brief says 2 dimms per channel will be 4400  so the later vendor seems correct.

???

[NormanS_Intel]

Hello cagey,

Thank you for posting in the community!

To ensure you receive the most specialized assistance, we have a dedicated forum that addresses these specific concerns. Therefore, I will be moving this discussion to our Server Products Forum. This will allow our knowledgeable community and experts to provide you with timely and accurate solutions.

Best regards,

Norman S.

Intel Customer Support Engineer

[RyanFeeko]

hi @cagey , just wondering where you get the processor brief so that i can refer to.  Do you mind to share with me? 

[cagey]

It's on Intel's web site - https://www.intel.com/content/www/us/en/products/docs/processors/xeon/5th-gen-xeon-product-brief.html

[RyanFeeko]

thanks @cagey for the info. Yeap i found the same in the doc mentioned - DDR5 at up to 5,600 MT/s (1 DIMM per channel)
or 4,400 MT/s (2 DIMMs per channel). Meaning to say if we using 1 dimm per channel it will run at 5600 speed and if we use 2 dimms then it will go 4400 speed.

However, i check in intel ARK for respective model : https://www.intel.com/content/www/us/en/products/sku/237255/intel-xeon-platinum-8558-processor-260m-cache-2-10-ghz/specifications.html  it shows this model supports Memory Types DDR5 @ 5200 MT/s (1 DPC). 

My opinion, just follow the spec support indicates in Intel ARK spec. Back to your inquiry, i believe if you wanted to run with 2 dimms per channel then we go for 5200 dimm speed. 

From your view, what will you choose for this one? Just for sharing idea.

[cagey]

I believe that the processor brief is saying that if you only use 1 DIMM per channel (DPC) you will get the speed listed in ARK for that particular processor ie 8558P=5600MT/s, 8558=5200MT/s.  But with 2 DPC, it doesn't matter which 5th gen platinum processor is used as it will always end up at 4400MT/s.  

If it's going to underclock the memory regardless of what the memory is rated at, then I'm paying extra for fast memory that will never show any benefit (unless its latency is lower).

[Simon-Intel]

Hi Cagey,

Good day!

Thank you for engaging with Intel Community.

I understand your inquiry pertains to the memory speed when utilizing the 5th generation Xeon 8558 with 2 DIMMs per channel. Allow me to provide you with the following specifications:

According to our findings, this processor can support 1 DPC (DIMMs per channel) at 5200MT/s and 2 DPC at 4400MT/s. The maximum memory size is 4TB, with a maximum of 8 memory channels.

I trust this information addresses your query adequately. Should you have any further questions or concerns regarding hardware support in the future, please feel free to reach out to us.

Thank you for your patience and cooperation.

Best regards,

Simon

[Simon-Intel]

Hi Cagey ,

Thank you for contacting Intel.

This is the first follow-up regarding the issue you reported to us.

We wanted to inquire whether you had the opportunity to review the information shared previously.

Feel free to reply to this message, and we'll be more than happy to assist you further.

Regards,

Simon

[Simon-Intel]

Hi Cagey,

Greetings for the day!

We would like to inform you that we are closing this request as no response has been received from our previous follow-ups.

Please don't hesitate to ask any further questions in the future. Feel free to start a new conversation, as this thread will no longer be monitored.

Best Regards,

Simon