EPYC 7643 vs Ryzen 9 3900X

Primary details

Comparing Ryzen 9 3900X and EPYC 7643 processor market type (desktop or notebook), architecture, sales start time and price.

Place in the ranking	275	38
Place by popularity	not in top-100	not in top-100
Cost-effectiveness evaluation	21.73	6.71
Market segment	Desktop processor	Server
Series	AMD Ryzen 9	AMD EPYC
Power efficiency	15.54	20.14
Architecture codename	Matisse (Zen 2) (2019−2020)	Milan (2021−2023)
Release date	7 July 2019 (5 years ago)	12 January 2021 (3 years ago)
Launch price (MSRP)	$499	$4,995

Cost-effectiveness evaluation

Performance per price, higher is better.

Ryzen 9 3900X has 224% better value for money than EPYC 7643.

Detailed specifications

Ryzen 9 3900X and EPYC 7643 basic parameters such as number of cores, number of threads, base frequency and turbo boost clock, lithography, cache size and multiplier lock state. These parameters indirectly say of CPU speed, though for more precise assessment you have to consider their test results.

Physical cores	12 (Dodeca-Core)	48 (Octatetraconta-Core)
Threads	24	96
Base clock speed	3.8 GHz	2.3 GHz
Boost clock speed	4.6 GHz	3.6 GHz
Multiplier	no data	23
L1 cache	768 KB	3 MB
L2 cache	6 MB	24 MB
L3 cache	64 MB	256 MB (shared)
Chip lithography	7 nm, 12 nm	7 nm+
Die size	no data	8x 81 mm2
Maximum core temperature	95 °C	no data
Number of transistors	19,200 million	33,200 million
64 bit support	+	+
Windows 11 compatibility	+	+
Unlocked multiplier	+	-

Compatibility

Information on Ryzen 9 3900X and EPYC 7643 compatibility with other computer components: motherboard (look for socket type), power supply unit (look for power consumption) etc. Useful when planning a future computer configuration or upgrading an existing one. Note that power consumption of some processors can well exceed their nominal TDP, even without overclocking. Some can even double their declared thermals given that the motherboard allows to tune the CPU power parameters.

Number of CPUs in a configuration	1 (Uniprocessor)	2
Socket	AM4	SP3
Power consumption (TDP)	105 Watt	225 Watt

Technologies and extensions

Technological solutions and additional instructions supported by Ryzen 9 3900X and EPYC 7643. You'll probably need this information if you require some particular technology.

AES-NI	+	+
AVX	+	+
Precision Boost 2	+	no data

Virtualization technologies

Virtual machine speed-up technologies supported by Ryzen 9 3900X and EPYC 7643 are enumerated here.

AMD-V

+

+

Memory specs

Types, maximum amount and channel quantity of RAM supported by Ryzen 9 3900X and EPYC 7643. Depending on the motherboard, higher memory frequencies may be supported.

Supported memory types	DDR4 Dual-channel	DDR4-3200
Maximum memory size	128 GB	4 TiB
Max memory channels	2	no data
Maximum memory bandwidth	51.196 GB/s	204.795 GB/s

Graphics specifications

General parameters of integrated GPUs, if any.

Integrated graphics card

-

N/A

Peripherals

Specifications and connection of peripherals supported by Ryzen 9 3900X and EPYC 7643.

PCIe version	no data	4.0
PCI Express lanes	no data	128

Synthetic benchmark performance

Various benchmark results of the processors in comparison. Overall score is measured in points in 0-100 range, higher is better.

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Combined synthetic benchmark score

This is our combined benchmark performance rating. We are regularly improving our combining algorithms, but if you find some perceived inconsistencies, feel free to speak up in comments section, we usually fix problems quickly.

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Pros & cons summary

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Performance score	20.53	47.88
Recency	7 July 2019	12 January 2021
Physical cores	12	48
Threads	24	96
Power consumption (TDP)	105 Watt	225 Watt

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Should you still have questions on choice between Ryzen 9 3900X and EPYC 7643, ask them in Comments section, and we shall answer.

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