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How to measure DRAM caching hit rate in MEMORY MODE?

John123
Beginner
518 Views

The memory mode of DCPMM uses DRAM to cache data, the DRAM cache read miss rate percentage shoule be a impotant metric,  so the question is How to measure DRAM caching hit rate in MEMORY MODE? what tools can help? Is the LLC hit rate same to DRAM caching hit rate in MEMORY MODE?

Thanks!

 

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3 Replies
JoseH_Intel
Moderator
500 Views

Hello John123,


Thank you for joining the community


In Memory Mode, the DRAM acts as a cache for the most frequently accessed data, while the Intel® Optane™ persistent memory (PMem) provides large memory capacity.


Cache management operations are handled by the Intel® Xeon® Scalable processor’s integrated memory controller.


When data is requested from memory, the memory controller first checks the DRAM cache, and if the data is present, the response latency is identical to DRAM. If the data is not in the DRAM cache, it is read from the Intel® Optane™ PMem with slightly longer latency.


The applications with consistent data retrieval patterns that the memory controller can predict will have a higher cache hit-rate, and should see its performance close to all-DRAM configurations, while workloads with highly random data access over a wide address range may see some performance difference versus DRAM alone.


Also, data is volatile in Memory Mode; it will not be saved in the event of power loss.


Persistence is enabled in the second mode, called App Direct.


About if there are software tools to get these metrics you can check the software pack here Download DCPM Software for Intel® Optane™ DC Persistent Memory for Windows* Server 2019


Regards


Jose A.

Intel Customer Support Technician

For firmware updates and troubleshooting tips, visit:

https://intel.com/support/serverbios


JoseH_Intel
Moderator
482 Views

Hello John123,


I am just following up to double-check if you found the provided information useful. If you have further questions please don't hesitate to ask. If you consider the issue to be completed please let us know so we can proceed to mark this ticket as closed. I will try to reach you back on next Tuesday 10th. After that the case will be automatically archived.


Regards


Jose A.

Intel Customer Support Technician

For firmware updates and troubleshooting tips, visit:

https://intel.com/support/serverbios


JoseH_Intel
Moderator
465 Views

Hello John123,


We will proceed to mark this thread as closed. If you have further issues or questions just go ahead and submit a new topic.


Regards


Jose A.

Intel Customer Support Technician

For firmware updates and troubleshooting tips, visit:

https://intel.com/support/serverbios


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