C – Troubleshooting BIOS Settings

Q

C.2.3

Incorrect MTRR Mapping Causes Unexpected Low Bandwidth

This same MTRR Mapping setting as described in the previous section can also cause unexpected low bandwidth if it is set incorrectly.

The setting should look like this:

MTRR Mapping

[Discrete]

The MTRR Mapping needs to be set to Discrete if there is 4GB or more memory in the system; it affects where the PCI, PCIe, and HyperTransport i/o addresses (BARs) are mapped. If there is 4GB or more memory in the system, and this is not set to Discrete, you will get very low bandwidth (under 250 MB/sec) on anything that would normally run near full bandwidth. The exact symptoms can vary with BIOS, amount of memory, etc., but typically there will be no errors or warnings.

To check your bandwidth try:

$ ipath_pkt_test -B

When configured correctly, PICIe InfiniPath will normally report in the range of 1150-1500 MB/s, while HTX InfiniPath cards will normally report in the range of 2300-2650 MB/s. ipath_checkout can also be used to check bandwidth.

You can check and adjust the BIOS settings using the BIOS Setup Utility. Check the hardware documentation that came with your system for more information on how to do this.

C.2.4

Change Setting for Mapping Memory

In some cases, on systems with 4GB or more memory on Opteron systems with InfiniPath HTX cards (QHT7040 or QHT7140), and the Red Hat Enterprise Linux 4 release with 2.6.9 Linux kernels, MPI jobs may fail to initialize or may terminate early. This can be worked around by changing the setting for mapping memory around the PCI configuration space ("SoftWare Memory Hole") to "Disabled" in the Chipset, Northbridge screen in the BIOS. This will result in a small loss in usable memory.

C.2.5

Issue with SuperMicro H8DCE-HTe and QHT7040

The InfiniPath card may not be recognized on startup when using the SuperMicro H8DCE-HT-e and the QHT7040 adapter. To fix this problem, the OS selector option in the BIOS should be set for Linux. The option will look like this:

OS Installation [Linux]

C-4

IB6054601-00 D

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Q-Logic IB6054601-00 D manual Incorrect Mtrr Mapping Causes Unexpected Low Bandwidth, Change Setting for Mapping Memory
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IB6054601-00 D specifications

The Q-Logic IB6054601-00 D is a high-performance InfiniBand adapter card designed for data centers and enterprise applications requiring robust connectivity and low-latency communication. This adapter is part of QLogic's extensive portfolio of networking solutions, catering to the needs of high-performance computing (HPC), cloud computing, and virtualization environments.

One of the standout features of the IB6054601-00 D is its capability to support data transfer rates of up to 56 Gbps. This makes it ideal for applications demanding large bandwidth and quick data processing. The adapter is optimized for RDMA (Remote Direct Memory Access) technology, which allows data to be transferred directly between the memory of different computers without involving the CPU. This reduces latency and CPU overhead, leading to enhanced overall system performance.

The architecture of the IB6054601-00 D includes support for a dual-port design, which offers increased bandwidth, redundancy, and fault tolerance. This dual-port configuration is especially advantageous for environments that require high availability and reliability, such as financial services and mission-critical applications.

The adapter utilizes advanced error detection and correction mechanisms, ensuring that data integrity is maintained during transmission. With features like adaptive routing and congestion management, the IB6054601-00 D is capable of optimizing the handling of data flows, thereby enhancing performance even under heavy loads.

In terms of compatibility, the Q-Logic IB6054601-00 D supports a wide range of operating systems and virtualization technologies, making it easy to integrate into diverse IT environments. It also includes drivers and software packages that facilitate seamless deployment and management.

In addition to high-speed connectivity, the adapter is designed with power efficiency in mind. It adheres to Energy Star regulations, helping organizations lower their operational costs while minimizing their environmental footprint.

Overall, the Q-Logic IB6054601-00 D stands out for its high throughput, low latency, and reliability. Its combination of advanced features and technologies positions it as an excellent choice for organizations looking to enhance their data center performance and maximize the efficiency of their network infrastructure. With the growing demands for faster and more efficient data transfer, solutions like the IB6054601-00 D are essential in meeting the evolving needs of modern enterprises.
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