Ryzen 5 8645HS vs Ryzen 9 3900X

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Aggregate performance score

Ryzen 9 3900X
2019
12 cores / 24 threads, 105 Watt
20.53
+41.9%
Ryzen 5 8645HS
2023
6 cores / 12 threads, 45 Watt
14.47

Ryzen 9 3900X outperforms Ryzen 5 8645HS by a considerable 42% based on our aggregate benchmark results.

Primary details

Comparing Ryzen 9 3900X and Ryzen 5 8645HS processor market type (desktop or notebook), architecture, sales start time and price.

Place in the ranking275499
Place by popularitynot in top-100not in top-100
Cost-effectiveness evaluation21.73no data
Market segmentDesktop processorLaptop
SeriesAMD Ryzen 9no data
Power efficiency15.5430.43
Architecture codenameMatisse (Zen 2) (2019−2020)Hawk Point-HS (Zen 4) (2023−2024)
Release date7 July 2019 (5 years ago)6 December 2023 (1 year ago)
Launch price (MSRP)$499no data

Cost-effectiveness evaluation

Performance per price, higher is better.

no data

Detailed specifications

Ryzen 9 3900X and Ryzen 5 8645HS 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 cores12 (Dodeca-Core)6 (Hexa-Core)
Threads2412
Base clock speed3.8 GHz4.3 GHz
Boost clock speed4.6 GHz5 GHz
L1 cache768 KB64 KB (per core)
L2 cache6 MB1 MB (per core)
L3 cache64 MB16 MB (shared)
Chip lithography7 nm, 12 nm4 nm
Die sizeno data178 mm2
Maximum core temperature95 °C100 °C
Number of transistors19,200 million25,000 million
64 bit support++
Windows 11 compatibility+no data
Unlocked multiplier+-

Compatibility

Information on Ryzen 9 3900X and Ryzen 5 8645HS 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 configuration1 (Uniprocessor)1
SocketAM4FP8
Power consumption (TDP)105 Watt45 Watt

Technologies and extensions

Technological solutions and additional instructions supported by Ryzen 9 3900X and Ryzen 5 8645HS. You'll probably need this information if you require some particular technology.

Instruction set extensionsno dataRyzen AI, AES, AVX, AVX2, AVX512, FMA3, MMX (+), SHA, SSE, SSE2, SSE3, SSE4.1, SSE4.2, SSE4A, SSSE3
AES-NI++
AVX++
Precision Boost 2++

Virtualization technologies

Virtual machine speed-up technologies supported by Ryzen 9 3900X and Ryzen 5 8645HS are enumerated here.

AMD-V++

Memory specs

Types, maximum amount and channel quantity of RAM supported by Ryzen 9 3900X and Ryzen 5 8645HS. Depending on the motherboard, higher memory frequencies may be supported.

Supported memory typesDDR4 Dual-channelDDR5
Maximum memory size128 GBno data
Max memory channels2no data
Maximum memory bandwidth51.196 GB/sno data

Graphics specifications

General parameters of integrated GPUs, if any.

Integrated graphics card-AMD Radeon 760M ( - 2600 MHz)

Peripherals

Specifications and connection of peripherals supported by Ryzen 9 3900X and Ryzen 5 8645HS.

PCIe versionno data4.0
PCI Express lanesno data20

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 3900X 20.53
+41.9%
Ryzen 5 8645HS 14.47

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 3900X 32613
+41.9%
Ryzen 5 8645HS 22985

3DMark06 CPU

3DMark06 is a discontinued DirectX 9 benchmark suite from Futuremark. Its CPU part contains two scenarios, one dedicated to artificial intelligence pathfinding, another to game physics using PhysX package.

Ryzen 9 3900X 14889
+5.9%
Ryzen 5 8645HS 14055

wPrime 32

wPrime 32M is a math multi-thread processor test, which calculates square roots of first 32 million integer numbers. Its result is measured in seconds, so that the less is benchmark result, the faster the processor.

Ryzen 9 3900X 2.69
+22.3%
Ryzen 5 8645HS 3.29

Cinebench 15 64-bit multi-core

Cinebench Release 15 Multi Core is a variant of Cinebench R15 which uses all the processor threads.

Ryzen 9 3900X 3049
+45.6%
Ryzen 5 8645HS 2094

Cinebench 15 64-bit single-core

Cinebench R15 (standing for Release 15) is a benchmark made by Maxon, authors of Cinema 4D. It was superseded by later versions of Cinebench, which use more modern variants of Cinema 4D engine. The Single Core version (sometimes called Single-Thread) only uses a single processor thread to render a room full of reflective spheres and light sources.

Ryzen 9 3900X 207
Ryzen 5 8645HS 270
+30.4%

TrueCrypt AES

TrueCrypt is a discontinued piece of software that was widely used for on-the-fly-encryption of disk partitions, now superseded by VeraCrypt. It contains several embedded performance tests, one of them being TrueCrypt AES, which measures data encryption speed using AES algorithm. Result is encryption speed in gigabytes per second.

Ryzen 9 3900X 10.8
Ryzen 5 8645HS 11
+2.3%

WinRAR 4.0

WinRAR 4.0 is an outdated version of a popular file archiver. It contains an internal speed test, using 'Best' setting of RAR compression on large chunks of randomly generated data. Its results are measured in kilobytes per second.

Ryzen 9 3900X 7534
+12.5%
Ryzen 5 8645HS 6695

x264 encoding pass 2

x264 Pass 2 is a slower variant of x264 video compression that produces a variable bit rate output file, which results in better quality since the higher bit rate is used when it is needed more. Benchmark result is still measured in frames per second.  

Ryzen 9 3900X 147
+20.7%
Ryzen 5 8645HS 122

x264 encoding pass 1

x264 version 4.0 is a video encoding benchmark uses MPEG 4 x264 compression method to compress a sample HD (720p) video. Pass 1 is a faster variant that produces a constant bit rate output file. Its result is measured in frames per second, which means how many frames of the source video file were encoded per second.  

Ryzen 9 3900X 268
Ryzen 5 8645HS 282
+5.2%

Geekbench 5.5 Multi-Core

Ryzen 9 3900X 10498
+11.4%
Ryzen 5 8645HS 9420

Blender(-)

Ryzen 9 3900X 162
Ryzen 5 8645HS 241
+48.5%

Geekbench 5.5 Single-Core

Ryzen 9 3900X 1250
Ryzen 5 8645HS 1915
+53.2%

7-Zip Single

Ryzen 9 3900X 5316
Ryzen 5 8645HS 6190
+16.4%

7-Zip

Ryzen 9 3900X 80935
+45.5%
Ryzen 5 8645HS 55608

WebXPRT 3

Ryzen 9 3900X 225
Ryzen 5 8645HS 295
+31.1%

Gaming performance

Pros & cons summary


Performance score 20.53 14.47
Recency 7 July 2019 6 December 2023
Physical cores 12 6
Threads 24 12
Chip lithography 7 nm 4 nm
Power consumption (TDP) 105 Watt 45 Watt

Ryzen 9 3900X has a 41.9% higher aggregate performance score, and 100% more physical cores and 100% more threads.

Ryzen 5 8645HS, on the other hand, has an age advantage of 4 years, a 75% more advanced lithography process, and 133.3% lower power consumption.

The Ryzen 9 3900X is our recommended choice as it beats the Ryzen 5 8645HS in performance tests.

Note that Ryzen 9 3900X is a desktop processor while Ryzen 5 8645HS is a notebook one.


Should you still have questions on choice between Ryzen 9 3900X and Ryzen 5 8645HS, ask them in Comments section, and we shall answer.

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AMD Ryzen 9 3900X
Ryzen 9 3900X
AMD Ryzen 5 8645HS
Ryzen 5 8645HS

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Community ratings

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