AMD Ryzen memory optimisation - The effect of tRC timings

Introduction

Introduction

When AMD's new Ryzen platform launched, memory support was all over the place, with many DIMMs refusing to run at their rated speeds and some kits that simply refused to boot at all.

Since then with the help of new BIOS/UEFI updates and the release of newer AMD AGESA microcode updates, things have improved tremendously, but that still does not mean that AMD's Ryzen platform is perfect in regards to memory support, especially when many new AGESA 1.0.0.6 BIOS versions are still in beta.



With the release of AGESA version 1.0.0.6 we promised to look deeper into the new options provided by the new update and through that search, we have found a neat little trick that will improve Ryzen's memory performance. Today we will be showing you not only how to test this new performance tweak yourself, but also have a look at the performance impact of this change in a wide range of scenarios.

tRC Memory Timings

In our initial Ryzen performance testing, we noticed a strange trait that was present on every AM4 motherboard that we tested so far. The motherboard always set the Bank Cycle Time (tRC) of our motherboard to 75 clocks, instead of the 48 clocks that were listed in the DIMMs XMP table.

This oddity was present in every Ryzen motherboard that we have tested so far, making this a general Ryzen problem, but why is it there? Is it for stability reasons? Performance reasons? The biggest question we have is whether or not changing this timing to our memory's default XMP value will result in a noticeable performance boost.

(We have heard reports that some recent ASRock BIOS files utilise XMP rated tRC Timings)

Test Hardware

We will be conducting our performance testing using ASUS' Crosshair VI Hero motherboard alongside AMD's Ryzen 7 1700X CPU. Here we will be using G.Skill's 3200MHz DDR4 memory on this test bed and use the same timings of 14-14-14-34 on ASUS' AGESA 1.0.0.6 BIOS releases (BIOS version 1403).

In this test, we will be using our Ryzen 7 1700X with a 4GHz overclock, effectively showcasing how this tweak can improve performance on a "pre-tweaked" Ryzen system. We will also look at how this tweak affects 2666MHz and 3200MHz memory speeds.

AMD Ryzen Game Test Rig

AMD Ryzen 7 1700X @ 4.0GHz

ASUS X370 Crosshair VI Hero

G.Skill Trident-Z 2x8GB DDR4 3200MHz

Corsair 460X System Chassis

Corsair RMi650

Corsair H115i

Nvidia GTX 1080 Founders Edition

Windows 10 x64 "Creators Update"





1 - Introduction 2 - AMD Ryzen tRC Timings - A Discovery 3 - Changing tRC timings and stability testing 4 - Performance testing and methodology 5 - AIDA 64 - Memory Performance and Latency 6 - Cinebench R15 7 - Geekbench 8 - x265 Benchmark 9 - 3DMARK Performance 10 - VRMARK 11 - Hitman (2016) 12 - Gears of War 4 13 - Total War: Warhammer 14 - Conclusion «Prev 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Next»

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