Ryzen 5 8400F vs Ryzen 9 3900

Place in the ranking	289	465
Place by popularity	not in top-100	not in top-100
Cost-effectiveness evaluation	20.33	59.63
Market segment	Desktop processor	Desktop processor
Series	AMD Matisse (Ryzen 3000 Desktop)	no data
Power efficiency	28.23	21.87
Architecture codename	Matisse (Zen 2) (2019−2020)	Phoenix (2023−2024)
Release date	24 September 2019 (5 years ago)	1 April 2024 (less than a year ago)
Launch price (MSRP)	$499	$170

Cost-effectiveness evaluation

Performance per price, higher is better.

Ryzen 5 8400F has 193% better value for money than Ryzen 9 3900.

Detailed specifications

Ryzen 9 3900 and Ryzen 5 8400F 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)	6 (Hexa-Core)
Threads	24	12
Base clock speed	3.1 GHz	4.2 GHz
Boost clock speed	4.3 GHz	4.7 GHz
L1 cache	768 KB	64 KB (per core)
L2 cache	6 MB	1 MB (per core)
L3 cache	64 MB	16 MB (shared)
Chip lithography	7 nm, 12 nm	4 nm
Die size	2x 74 mm²	178 mm²
Number of transistors	7,600 million	25,000 million
64 bit support	+	+
Windows 11 compatibility	-	no data
Unlocked multiplier	+	+

Compatibility

Information on Ryzen 9 3900 and Ryzen 5 8400F 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	1
Socket	AM4	AM5
Power consumption (TDP)	65 Watt	65 Watt

Technologies and extensions

Technological solutions and additional instructions supported by Ryzen 9 3900 and Ryzen 5 8400F. You'll probably need this information if you require some particular technology.

Instruction set extensions	86x MMX(+), SSE, SSE2, SSE3, SSSE3, SSE4.1, SSE4.2, SSE4A,-64, AMD-V, AES, AVX, AVX2, FMA3, SHA, Precision Boost 2	no data
AES-NI	+	+
AVX	+	+
Precision Boost 2	+	+

Virtualization technologies

Virtual machine speed-up technologies supported by Ryzen 9 3900 and Ryzen 5 8400F are enumerated here.

AMD-V

Memory specs

Types, maximum amount and channel quantity of RAM supported by Ryzen 9 3900 and Ryzen 5 8400F. Depending on the motherboard, higher memory frequencies may be supported.

Supported memory types	DDR4-3200	DDR5
Maximum memory size	128 GB	no data
Max memory channels	2	no data
Maximum memory bandwidth	51.196 GB/s	no data

Graphics specifications

General parameters of integrated GPUs, if any.

Integrated graphics card

N/A

Peripherals

Specifications and connection of peripherals supported by Ryzen 9 3900 and Ryzen 5 8400F.

PCIe version	4.0	4.0
PCI Express lanes	24	20

Synthetic benchmark performance

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

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.

Ryzen 9 3900 20.12
+29.1%

Ryzen 5 8400F 15.59

Passmark

Passmark CPU Mark is a widespread benchmark, consisting of 8 different types of workload, including integer and floating point math, extended instructions, compression, encryption and physics calculation. There is also one separate single-threaded scenario measuring single-core performance.

Ryzen 9 3900 30796
+29.1%

Ryzen 5 8400F 23852