User Manual

AMD Ryzen™ Master Overclocking User’s Guide

55931 Rev. 1.20 February 2018

AMD Ryzen™ Master Application

7. Memory Control – Memory module parameters

System memory timing adjustment can be made using the specifications typically supplied

with the memory module for CAS Latency (tCL), Row Precharge Delay (tRP), RAS Active

Time (tRAS), Read Row-Column Delay (tRCD). Additionally, Row Cycle Time (tRC),

Processor On-Die Termination and CAS Write Latency can be set.

Note that changing the memory clock and/or parameters requires a Windows Restart that

Ryzen Master will automatically initiate, then Ryzen Master will automatically open after re-

start. However, during the restart, the processor will be attempting to train the memory

performance to the new parameters. Most motherboard BIOSes set a limit for the number of

failed attempts to train memory, such as five, before the BIOS resets to the prior, known-good

memory setting and allows the restart to complete. If your system fails to train memory to

your settings, Ryzen Master will automatically start and show operation under the functional

memory parameters.

For even more detailed memory overclocking, your motherboard may offer additional control

through a BIOS utility.

8. Additional Control

a. Many Ryzen processors feature Simultaneous Multithreading (SMT) operation where

some of a core’s resources are shared between two threads. This feature accelerates the

performance of many applications, but the user may wish to force each core to operate on

only one application thread. If the Ryzen processor model supports the SMT feature, this

control can turn it off, requiring a Windows Restart that Ryzen Master will automatically

initiate then re-open.

b. The feature formerly offered as Extreme Software Acceleration is a feature useful for some

extreme application workloads that operate with exceptionally tight code loops.

Geekbench is one example. This feature is the default for Ryzen Threadripper processors,

and is now engaged automatically in Ryzen Master 1.2 for Ryzen processors when

overclocked, thus the feature is no longer offered as an option.

c. Memory Access Mode provides two settings for applications access to memory when

using Ryzen Threadripper processors:

• Distributed Mode modifies how your AMD Ryzen Threadripper processor accesses

your PC's RAM to enhance the performance of creative applications (e.g., 3D modeling

or video rendering). This mode evenly distributes memory requests across your PC's

RAM. Even distribution of memory transactions maximizes memory bandwidth, which

is often preferred by creative workloads.

• Local Mode modifies how your AMD Ryzen Threadripper processor accesses your

PC's RAM to enhance the performance of games. This mode routes memory requests

to RAM that is electrically nearest to the processor cores(s) communicating with your

graphics card. Using memory with the shortest electrical path to the processor

minimizes memory access times, which is often preferred by games.