SPEC
Base frequency 3.8GHz
Turbo frequency 4.6GHz
Core Zen 2
Manufacturing process 7nm
Number of cores 12 x physical (24 threads)
IGP None
Simultaneous Multithreading Ye s
Cache 64MB L3 cache, 6MB L2 cache
Memory controller Dual-channel
DDR4, up to 3200MHz
Packaging AMD Socket AM4
Thermal design power (TDP) 105W
Features Precision Boost 2, Precision Boost
Overdrive, FMA3, F16C, SHA, BMI / BMI1 + BMI2,
AVX2, AVX, AES, SSE4a, SSE4, SSE3, SSE2, SSEI
f you’d said that 12-core CPUs would
be available for under £450 on
mainstream desktop platforms two
years ago, we’d probably have laughed in your
face. However, the Ryzen 9 3900X landed last
summer, took the PC industry by storm and
caused some serious problems for Intel.
While the X570 platform lacks quad-
channel memory support and enough PCI-E
lanes to properly deal with several GPUs or
many M.2 SSDs being accessed at the same
time, the fact that this mainstream chipset
can still handle several speedy PCI-E 4
M.2 SSDs, and accommodate 12-core and
16-core powerhouses, is a great benefit.
It means AMD is offering serious content
creation-crunching performance for very
reasonable prices, and with comparatively
cheap and varied motherboard options too.
With 12 cores (and 24 threads via SMT), as
well as the benefits of the Zen 2 architecture,
the Ryzen 9 3900X even outshines the
Threadripper 2950X in many tests, and itsAMD RYZEN 9
3900X /£440 inc VAT
SUPPLIER overclockers.co.ukprice has dropped by
around £40 since its
launch as well. It boasts
two Core Chiplet Dies
(CCD) with two Core
Complexes (CCX) each,
and each of those CCXs
sport four cores. However, four cores are
disabled on this CPU, bringing the total to 12.
You also get the same huge 64MB L3 cache
as the Ryzen 9 3950X, with just a small cut in the
L2 cache thanks to four cores being disabled.
Meanwhile, the 3900X offers the second fastest
peak boost frequency of all 3rd-gen Ryzen CPUs
at 4.6GHz, and it hit 4.05GHz across all cores in
our multi-threaded tests.
As such, the benefits of overclocking are
variable. We only managed to achieve an
all-core overclock of 4.3GHz, even when
we pushed the vcore up to 1.425V. This
results in a huge 300MHz step down from
the stock speed peak boost, but it does
give you a 250MHz increase to the all-core
boost. Precision Boost Overdrive will likely
add a little more to the all-core boost, while
enabling you to keep that 4.6GHz peak boost,
but it won’t be the best option for maximising
multi-threaded performance.
In terms of performance, the RealBench
system score of 306,884 was second only
to the Ryzen 9 3950X, beating the mighty
Core i9-10940X in every RealBench test.
It was neck and neck with the Intel CPU
in Cinebench too, but the Intel chip was
significantly quicker in Premiere Pro, as wasthe Core i9-10920X. The AMD CPU was
slightly quicker in Far Cry New Dawn as well,
but dropped a little behind in Metro Exodus.
Even when overclocked, the Core
i9-10940X failed to topple the Ryzen 9
3900X in RealBench but it managed a faster
Handbrake score, with the AMD CPU not
benefiting that much from overclocking. The
Intel CPU’s massive all-core overclock gave it
a commanding lead in Premiere Pro as well,
while edging out a lead in our game tests,
albeit with far higher power consumption.Conclusion
If you have £500 to spend on a CPU and
need it primarily for content creation, or if
you game at high resolutions, the Ryzen 9
3900X is brilliant. It matches or betters far
more expensive Intel CPUs and is one of
the best AMD CPUs in games. Intel still has
a lead in some games at certain settings,
but if you play at higher, more GPU-limited
resolutions and also need multi-threaded
grunt, the Ryzen 9 3900X is unbeatable.VERDICT
With fantastic multi-threaded power and
solid gaming pace, the Ryzen 9 3900X is
the best sub-£500 CPU.
24CARAT GOLD
+ Excellent multi-
threaded performance
+ Better value than Intel
for content creation
+ Power-efficient24HOUR SHIFT- Slower than Intel
in some games - Poor overclocking
headroom - No faster than Ryzen
3700X in games
PERFORMANCE
45 / 50FEATURES
13 / 15OVERALL SCORE
87 %
VALUE
29 / 35c
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SPEC
Basefrequency3.8GHz
Turbofrequency4.6GHz
CoreZen 2
Manufacturingprocess7nm
Numberofcores 12 x physical(24threads)
IGPNone
SimultaneousMultithreadingYe s
Cache64MBL3cache,6MBL2cache
MemorycontrollerDual-channel
DDR4, up to 3200MHz
Packaging AMD Socket AM4
Thermal design power (TDP) 105W
Features Precision Boost 2, Precision Boost
Overdrive, FMA3, F16C, SHA, BMI / BMI1 + BMI2,
AVX2, AVX, AES, SSE4a, SSE4, SSE3, SSE2, SSEI
f you’dsaidthat12-coreCPUswould
beavailableforunder£450on
mainstreamdesktopplatformstwo
yearsago,we’dprobablyhavelaughedinyour
face.However,theRyzen9 3900Xlandedlast
summer,tookthePCindustrybystormand
causedsomeseriousproblemsforIntel.
WhiletheX570platformlacksquad-
channelmemorysupportandenoughPCI-E
lanestoproperlydealwithseveralGPUsor
manyM.2SSDsbeingaccessedatthesame
time,thefactthatthis mainstreamchipset
canstillhandleseveralspeedyPCI-E 4
M.2SSDs,andaccommodate12-coreand
16-corepowerhouses,isa greatbenefit.
It meansAMDisofferingseriouscontent
creation-crunchingperformanceforvery
reasonableprices,andwithcomparatively
cheapandvariedmotherboardoptionstoo.
With 12 cores(and 24 threadsviaSMT),as
wellasthebenefitsoftheZen2 architecture,
theRyzen9 3900Xevenoutshinesthe
Threadripper2950Xinmanytests,andits
AMD RYZEN 9
3900X/£440inc VAT
SUPPLIER overclockers.co.ukprice has dropped by
around £40 since its
launch as well. It boasts
two Core Chiplet Dies
(CCD) with two Core
Complexes (CCX) each,
and each of those CCXs
sport four cores. However, four cores are
disabled on this CPU, bringing the total to 12.
You also get the same huge 64MB L3 cache
as the Ryzen 9 3950X, with just a small cut in the
L2 cache thanks to four cores being disabled.
Meanwhile, the 3900X offers the second fastest
peak boost frequency of all 3rd-gen Ryzen CPUs
at 4.6GHz, and it hit 4.05GHz across all cores in
our multi-threaded tests.
As such, the benefits of overclocking are
variable. We only managed to achieve an
all-core overclock of 4.3GHz, even when
we pushed the vcore up to 1.425V. This
results in a huge 300MHz step down from
the stock speed peak boost, but it does
give you a 250MHz increase to the all-core
boost. Precision Boost Overdrive will likely
add a little more to the all-core boost, while
enabling you to keep that 4.6GHz peak boost,
but it won’t be the best option for maximising
multi-threaded performance.
In terms of performance, the RealBench
system score of 306,884 was second only
to the Ryzen 9 3950X, beating the mighty
Core i9-10940X in every RealBench test.
It was neck and neck with the Intel CPU
in Cinebench too, but the Intel chip was
significantly quicker in Premiere Pro, as wasthe Corei9-10920X.TheAMDCPUwas
slightlyquickerinFarCryNewDawnaswell,
but droppeda littlebehindinMetroExodus.
Even when overclocked, the Core
i9-10940X failed to topple the Ryzen 9
3900X in RealBench but it managed a faster
Handbrake score, with the AMD CPU not
benefiting that much from overclocking. The
Intel CPU’s massive all-core overclock gave it
a commanding lead in Premiere Pro as well,
while edging out a lead in our game tests,
albeit with far higher power consumption.Conclusion
If you have £500 to spend on a CPU and
need it primarily for content creation, or if
you game at high resolutions, the Ryzen 9
3900X is brilliant. It matches or betters far
more expensive Intel CPUs and is one of
the best AMD CPUs in games. Intel still has
a lead in some games at certain settings,
but if you play at higher, more GPU-limited
resolutions and also need multi-threaded
grunt, the Ryzen 9 3900X is unbeatable.VERDICT
With fantastic multi-threaded power and
solid gaming pace, the Ryzen 9 3900X is
thebestsub-£500CPU.
24CARAT GOLD
+ Excellent multi-
threaded performance
+ Better value than Intel
for content creation
+ Power-efficient24HOUR SHIFT- Slower than Intel
in some games - Poor overclocking
headroom - No faster than Ryzen
3700X in games
PERFORMANCE
45 / 50FEATURES
13 / 15OVERALLSCORE
87 %
VALUE
29 / 35cc
uuss
tommPP
CCP
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IU
M^ GR
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