Analyze Memory and Cross-Socket Bandwidth
Non-optimal application topology can result in induced DRAM and Intel® QuickPath Interconnect (Intel® QPI) or Intel® Ultra Path Interconnect (Intel® UPI) cross-socket traffic, which can limit performance.
tab to correlate
Inbound PCIe Traffic
with DRAM and cross-socket interconnect bandwidth consumption:
provides per-channel breakdown of DRAM bandwidth.
Two metrics are available for UPI traffic:
UPI Utilization Outgoing
– ratio metric that shows UPI utilization in terms of transmit.
– shows detailed bandwidth information with breakdown by data/non-data.
You can get a breakdown of UPI metrics by UPI links. See the specifications of your processor to determine the number of UPI links that are enabled on each socket of your processor.
UPI link names reveal the topology of your system by showing which sockets and UPI controllers they are connected to.
Below is an example of a result collected on a four-socket server powered by Intel® processors with microarchitecture code named Skylake. The data reveals significant UPI traffic imbalance with bandwidth being much higher on links connected to socket 3: