T
hestoryofAMD’sZen CPUs and memory speed
hasbeena complicated and often frustrating one,
withearlyCPUsand motherboards being highly
unoptimisedwhenit cametomemory support. Running
yourmemoryfasterthan3000MHz on 1st-gen Ryzen
systemsoriginallyrequiredvery specific memory dies, or
you’dbestuckat2933MHz.It took several months and a few
BIOSupdatesbeforewecould run most memory at high
frequenciesonthefirstZenchips.
Thatwasunfortunate,because memory speed is very
importantwithZenCPUs,whether it’s an AM4 Ryzen chip or a
Threadripperprocessor.Allthese chips have a high-speed
interconnect,otherwiseknown as Infinity Fabric, which is
directlyrelatedtomemoryspeed. This in turn impacts on the
performanceoftheCPU,sousing fast memory can make all
sortsofsoftware,fromgamesto content creation, run faster.
TheZen2 architectureintroduced a better memory controller,
alongwitha stackofmotherboard AGESA code tweaks from
motherboardmanufacturers,and 3rd-gen Ryzen CPUs are
nowhappytorunmemoryat3600MHz memory speed while
maintaininga 1:1ratiowiththeInfinity Fabric.
Goabovethisfrequency,and some motherboards will
starttousedividers,knocking back the Infinity Fabric clock,
butallowingforfastermemory to be used. In short, you
shouldaimfora RAMfrequencyof3600MHzorbelow,WHAT’STHEBEST
MEMORYFOR3RDGE
THREADRIPPER?
especially as memory prices can rocket above this speed.
For AMD’s standard AM4 Ryzen CPUs, we recommend
3466MHz memory, as it performs closely to 3600MHz
RAM, while offering a decent gain over 3200MHz memory.
Is the same true for 3rd-gen Threadripper? To find out, we
tested the Threadripper 3970X with a quad-channel Corsair
Vengeance RGB Pro kit clocked at 2666MHz, 3200MHz,
3466MHz and 3600MHz.
As you can see from the results, 2666MHz should be
avoided with these high-end systems, as it hammers
performance in nearly every benchmark, especially games
and multi-tasking, while it was 15 per cent slower than
3600MHz memory in our video encoding test too. Stepping
up to 3200MHz saw the frame rate in Far Cry 5 recover to
almost normal levels, leaping from a 78fps minimum to 88fps.
However, moving up to 3466MHz saw a 6 per cent
improvement in the video encoding test and 5fps added to
the average frame rate in Far Cry 5, along with a substantial
rise in multi-tasking performance. The final notch up to
3600MHz did yield a noticeable boost to the video encoding
score of around 8 per cent, but Far Cry 5, multi-tasking,
Cinebench and image editing saw meagre gains.
Overall, the situation is much the same as with AMD’s
mainstream 3rd-gen Ryzen CPUs. Memory speeds below
3000MHz should be avoided, as they rapidly see huge drops
in a number of tests. If you find a
particularly good-value 3200MHz
kit, you won’t lose vast amounts
of performance, but considering
you’re spending a sizeable
amount on your system already,
moving up to 3466MHz is
absolutely worth the extra money.
Going up to 3600MHz only
gave us a notable improvement in
one benchmark. Plus, as most
3466MHz memory kits will
overclock to 3600MHz anyway,
this being Custom PC, we’d much
rather tweak the BIOS and save
some cash, so 3466MHz is our
recommendation. However, if you
find a 3600MHz kit going cheap, it
will still offer a small performance
improvement without the hassle
of overclocking.
ANTONY LEATHERREVIEWS /PROCESSORS
GIMPIMAGEEDITING0 20k 40k 60k 80k2666MHz 61,
3200MHz 61,
3466MHz 61,
3600MHz 63,HANDBRAKEH.264VIDEOENCODING0 300k 600k 900k 1.2mil2666MHz 1,000,
3200MHz 1,002,
3466MHz 1,064,
3600MHz 1,146,HEAVYMULTITASKING0 100k 200k 300k 400k2666MHz 292,
3200MHz 307,
3466MHz 323,
3600MHz 323,SYSTEMSCORE0 100k 200k 300k 400k2666MHz 344,
3200MHz 348,
3466MHz 368,
3600MHz 388,CINEBENCHR20MULTITHREADED0 5k 10k 15k 20k2666MHz 17,
3200MHz 17,
3466MHz 17,
3600MHz 17,FARCRY 50 50fps 100fps 150fps 200fps2666MHz
3200MHz
3466MHz
3600MHz1,920 x 1,080, Ultra settings
99fps
110fps
115fps
115fps78fps
88fps
90fps
91fpsBENCHMARK RESULTS