Specifications

April 2012 v1 AMD Opteron™ 6200 Linux Tuning Guide
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2.0 Getting Started
Start by ensuring your system is configured properly. Since memory configuration is critical to performance
and vulnerable to misconfiguration, you will verify proper memory configuration by inspection, observing
Linux’s view of the memory configuration, and finally by verifying the memory performance using the STREAM
benchmark.
In this section you will:
• Check physical memory configuration.
• Select specific BIOS options.
• Check NUMA configuration.
• Use STREAM to verify configuration.
• Run HPL.
2.1 Physical Memory Configuration Check
Always ensure you are using a balanced and symmetrical memory configuration. Follow the manufacturer’s
configuration guide, if available. Otherwise,
1. Ensure that all DIMMS installed are identical. Identical means DIMMs from the same manufacturer,
model, speed, CAS, ranks, etc.
2. The least error-prone memory configuration is to have all memory sockets occupied with identical
DIMMs. But, if one DIMM per memory channel is the desired configuration, be very careful to install
a DIMM in the DIMM socket most distant from the CPU and to have exactly one DIMM per memory
channel. Be careful not to plug two DIMMs into one channel, leaving an empty channel. In most
systems that have two DIMM sockets per memory channel, you will achieve the best memory
bandwidth when using Dual Rank DDR3 1600 DIMMs with one or two DIMMs per channel.
3. Consult the loading tables for the platform for supported DIMMs and configuration that achieve the
best capacity and performance. Note that not all platforms support 1600 DIMMs. Having three DIMM
sockets per channel can provide more capacity but will restrict memory bus frequency and make it
more dependent on which DIMMs are supported at full speed. Be sure to check the manufacturer’s
documentation.
2.2 BIOS Configuration Summary
1. Load BIOS defaults.
2. Set the date and time.
3. Node Interleaving = Disabled.
4. Power Management/C1E = Disabled.
5. Core Performance Boost (CPB) = Disabled.
6. C6-State = Disabled.
7. Downcoring = Disabled.
8. HPC/Optimization Mode (if it exists) = Enabled.