Summary

New PowerEdge servers fueled by 4th Generation Intel® Xeon® Scalable Processors can support eight DIMMs per CPU and up to 4800 MT/memory speeds. This document compares memory bandwidth readings observed on new PowerEdge servers with Sapphire Rapids CPU architecture against prior-gen PowerEdge servers with Ice-Lake CPU architecture.

Sapphire Rapids CPU architecture

4th Generation Intel® Xeon® Scalable Processors, known as Sapphire Rapids processors, are the designated CPU for new Dell PowerEdge servers.

Compared to prior-gen 3rd Generation Intel® Xeon® Scalable Processors, Sapphire Rapids Architecture supports up to 50% higher memory bandwidth (4800MTS (1DPC)/4400MTS(2DPC) on 4th Gen Intel® Xeon® Scalable Processors vs 3200MT/s on Ice Lake Processors).

Performance Data

To quantify the impact of this increase in memory support, we performed two studies. The first study[1] (see Figure 1) measured memory bandwidth determined by the number of DIMMs per CPU populated. To measure the memory bandwidth, we used the STREAM Triad benchmark. STREAM Triad is a synthetic benchmark that is designed to measure sustainable memory bandwidth (in MB/s) and a corresponding computation rate for four simple vector kernels. Of all the vector kernels, Triad is the most complex scenario. It was run on previous generation Dell PowerEdge R750 powered by Intel® Ice Lake CPU populated with eight DDR4 3200MT/s DIMMs per channel and the latest generation Dell PowerEdge R760 powered by Intel’s latest Sapphire Rapids populated with eight DDR5 4800MT/s DIMMs per channel. As a result, we saw a performance increase of 53% for 6 DIMMs per channel and 46% for 8 DIMMS per channel.

Figure 1.  Sapphire Rapids and Ice Lake bandwidth comparison by # of DIMMs per CPU

The second study[1][2] (see Figure 2) measured memory bandwidth determined by the number of CPU thread cores. Both STREAM bandwidth benchmarks have Sapphire Rapids populated with eight DDR5 4800MT/s DIMMs per channel, and Ice Lake populated with eight DDR4 3200 MT/s DIMMs per channel. This resulted in up to 50% more aggregate bandwidth available for 32+ core threads, which is ideal for memory applications such as SAP HANA, MSFT SQL, and VDI.

Figure 2.  Sapphire Rapids and Ice Lake bandwidth comparison by # of CPU core threads

Conclusion

With improved bandwidth, and continuous improvements for providing a quality customer experience on memory, all provided in a dense form factor of DDR5, Dell Technologies continues to provide best-in-class features and specifications for its constantly evolving better and faster PowerEdge server portfolio.