Symptoms
See Figure 1, which shows sequential read throughput with 10 SATA SSDs. Each SSD achieved 530 MB/s,
Totaling 5.3 GB/s
See Figure 2, which shows sequential read throughput with 12 SATA SSDs. 4 SSDs achieved 430 MB/s, the other 8 achieved 220 MB/s,
Totaling 3.5 GB/s
Figure 1: Sequential Read throughput on 10 SATA SSDs
Figure 2: Sequential Read throughput on 12 SATA SSDs
Cause
The default BIOS setting is not optimized for I/O performance.
Red Hat Enterprise Linux (RHEL) 8.3 has storage performance improvements that are unavailable in Red Hat Enterprise Linux 7.x.
PERC H345 and H745 are PCIe Gen3 x8 devices. The maximum throughput is 7GB/s.
Resolution
Install Red Hat Enterprise Linux 8.3 or newer for I/O performance testing.
Follow these instructions for BIOS SETUP tuning:
- Boot into BIOS Setup and press Alt-F2 to load the default setting.
- Navigate to 'Processor Settings'. Disable 'Virtualization Technology', set 'MADT Core Enumeration' to 'Round Robin', and 'Numa Nodes Per Socket' to 4 (See Figure 4).
- Go to 'System Profile settings'. Set 'System Profile' to Custom, 'CPU Power Management" to 'Maximum Performance', 'C State' to 'Disabled' and 'Determinism Slider' to 'Performance Determinism' (See Figure 5).
Figure 3: BIOS Setup: Processors Settings
Figure 4: BIOS Setup: System Profile Settings
Affected Products
PowerEdge RAID Controller H345, PowerEdge RAID Controller H745, PowerEdge R7525