Visible to Intel only — GUID: yjo1743454403663
Ixiasoft
Visible to Intel only — GUID: yjo1743454403663
Ixiasoft
2.2.8. LPDDR5 and DDR5 maximum bandwidth for sequential short write is limited
Description
In LPDDR5 and DDR5 memory interfaces, when using x16 2-channel configuration for short burst sequential access during write operations, in any access mode, the secondary hard memory controller write performance is limited to 80%.
There is no performance limitation in the following configurations:
- DDR5 x32 configuration in DIMM or component configuration
- LPDDR5 x32 configuration
- LPDDR5 x16 1-channel when placed in the bottom GPIO-B sub-bank
- DDR5 x16 1-channel
- LPDDR5 x16/DDR5 x16 configurations with random access and in sequential access with mixed read-write traffic
Impacted configurations:
- LPDDR5 x16 2-channel configuration only with short sequential write with all three access modes (Fabric Sync, Fabric Async, and NoC)
- LPDDR5 x16 1-channel when placed in the top GPIO-B sub-bank
- DDR5 x16 2-channel
Workaround
There is no workaround available when using NoC access mode.
For Fabric Async and Fabric Sync access mode, using longer bursts prevents performance loss.
Status
Devices Affected | Planned Fix |
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None |