Ryzen 9 3900 vs Ryzen 9 8945H

CPU

GPU

Ryzen 9 3900

12 Cores24 Thrd65 WWMax: 4.3 GHz2019

Ryzen family

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Ryzen 9 8945H

8 Cores16 Thrd8 WWMax: 5.2 GHz2023

Ryzen family

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Ryzen 9 3900 vs Ryzen 9 8945H Performance Spectrum

Ryzen 9 3900

12 / 24

30,588

+1.2%

Ryzen Threadripper 3970X

Ryzen Threadripper 3990X

Ryzen Threadripper PRO 5995WX

Ryzen 9 8945H

8 / 16

30,240

0.0%

Ryzen Threadripper 3970X

Ryzen Threadripper 3990X

Ryzen Threadripper PRO 5995WX

About PassMark

PassMark CPU Mark evaluates processor speed through complex mathematical computations. It provides a reliable metric to compare multi-core performance, where higher scores indicate faster processing for multitasking, gaming, and heavy workloads.

Ryzen 9 3900 vs Ryzen 9 8945H FPS Benchmarks

Predicted gaming performance across popular games. Tested paired with GeForce RTX 5090 to isolate CPU performance.

Search any supported game below to compare 1080p FPS for both components.

Ryzen 9 3900 vs Ryzen 9 8945H: Pros, Cons & Final Verdict

See where each CPU makes more sense in practice: gaming, heavier work, platform cost, power draw, and upgrade path.

Ryzen 9 3900

2019

Why buy it

✅+1.1% higher Cinebench R23 multi-core.
✅+300% larger total L3 cache (64 MB vs 16 MB).
✅20% more PCIe lanes (24 vs 20) for storage and expansion-heavy builds.
✅Includes a boxed cooler (Wraith Prism), unlike Ryzen 9 8945H.

Trade-offs

❌Worse for gaming: lower average FPS than Ryzen 9 8945H across 50 shared CPU benchmark tests.
❌Launch MSRP is still $499 MSRP, while Ryzen 9 8945H mostly shows up through inconsistent older-market listings.
❌712.5% higher power demand at 65W vs 8W.
❌Older platform position on AM4 with DDR4, while Ryzen 9 8945H moves to FP7/FP7r2/FP8 and DDR5.
❌No integrated graphics, while Ryzen 9 8945H can still boot and troubleshoot without a discrete GPU.

Ryzen 9 8945H

2023

Why buy it

✅Better for gaming: +20.2% higher average FPS across 50 shared CPU benchmark tests.
✅Draws 8W instead of 65W, a 57W reduction.
✅Newer platform on FP7/FP7r2/FP8 with DDR5 support instead of AM4 and DDR4.
✅Integrated graphics onboard with Radeon 780M, while Ryzen 9 3900 needs a discrete GPU.

Trade-offs

❌Lower Cinebench R23 multi-core (17,500 vs 17,700).
❌Smaller total L3 cache (16 MB vs 64 MB).
❌No boxed cooler included, unlike Ryzen 9 3900.

Quick Answers

So, is Ryzen 9 8945H better than Ryzen 9 3900?

It depends on what you want from the system. For gaming, Ryzen 9 8945H is ahead with a 20.2% average FPS lead across 50 shared CPU game tests in our data. For rendering, compiling, streaming, and heavier multitasking, Ryzen 9 3900 pulls ahead with 1.1% better Cinebench R23 multi-core. Ryzen 9 3900 also has the bigger cache pool with 300% larger total L3 cache (64 MB vs 16 MB).

Which one is better for streaming, content creation, and heavy multitasking?

For streaming, content creation, and heavier multitasking, Ryzen 9 3900 is the stronger fit. You are getting 1.1% better Cinebench R23 multi-core, backed by 12 cores and 24 threads. It also has the larger cache pool with 300% larger total L3 cache (64 MB vs 16 MB).

Which one is the smarter buy today, not just the cheaper CPU?

Ryzen 9 8945H is still the faster CPU overall, but Ryzen 9 3900 is easier to justify if budget matters more than peak performance. Ryzen 9 8945H comes in at an unclear MSRP at unclear MSRP versus $499 MSRP, and it still gives you a 20.2% average FPS lead across 50 shared CPU game tests in our data. The compromise is that Ryzen 9 3900 is still stronger for heavier multi-core work with 1.1% better Cinebench R23 multi-core. Ryzen 9 3900 is also 100.0% better value on MSRP (61.3 vs 0.0 PassMark/$), which is why it can still make sense for tighter-budget builds on paper.

Which one is more future-proof for 2026 and beyond?

Ryzen 9 8945H makes more sense long term for 2026 and beyond. You are getting a newer CPU generation (2023 vs 2019) and a healthier platform with FP7/FP7r2/FP8 and DDR5 instead of AM4. That gives you a healthier platform runway for motherboard, RAM, and later CPU upgrades.

Ryzen 9 3900 vs Ryzen 9 8945H Technical Specifications

Side-by-side specs, architecture details, clocks, memory, power, and platform differences.

Ryzen 9 3900

The Ryzen 9 3900 is manufactured by AMD. It was released in 24 September 2019 (6 years ago). It is based on the Matisse (Zen 2) (2019−2020) architecture. It features 12 cores and 24 threads. Base frequency is 3.1 GHz, with boost up to 4.3 GHz. L3 cache: 64 MB. L2 cache: 512 kB (per core). Built on 7 nm, 12 nm process technology. Socket: AM4. Thermal design power (TDP): 65 Watt. Memory support: DDR4-3200. Passmark benchmark score: 30,588 points. Launch price was $499.

Ryzen 9 8945H

The Ryzen 9 8945H is manufactured by AMD. It was released in 6 December 2023 (1 year ago). It is based on the Hawk Point-HS (Zen 4) (2023−2024) architecture. It features 8 cores and 16 threads. Base frequency is 4 GHz, with boost up to 5.2 GHz. L3 cache: 16 MB. L2 cache: 8 MB. Built on 4 nm process technology. Socket: FP7/FP7r2/FP8. Thermal design power (TDP): 8 MB + 16 MB. Memory support: DDR5. Passmark benchmark score: 30,240 points. Launch price was $499.

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Processing Power

The Ryzen 9 3900 packs 12 cores / 24 threads, while the Ryzen 9 8945H offers 8 cores / 16 threads — the Ryzen 9 3900 has 4 more cores. Boost clocks reach 4.3 GHz on the Ryzen 9 3900 versus 5.2 GHz on the Ryzen 9 8945H — a 18.9% clock advantage for the Ryzen 9 8945H (base: 3.1 GHz vs 4 GHz). The Ryzen 9 3900 uses the Matisse (Zen 2) (2019−2020) architecture (7 nm, 12 nm), while the Ryzen 9 8945H uses Hawk Point-HS (Zen 4) (2023−2024) (4 nm). In PassMark, the Ryzen 9 3900 scores 30,588 against the Ryzen 9 8945H's 30,240 — a 1.1% lead for the Ryzen 9 3900. Cinebench R23 multi-core: 17,700 vs 17,500 (1.1% advantage for the Ryzen 9 3900). Geekbench 6 single-core — the metric most relevant to gaming — records 1,713 vs 2,617, a 41.8% lead for the Ryzen 9 8945H that directly translates to higher frame rates. Multi-core Geekbench: 10,983 vs 12,662 (14.2% advantage for the Ryzen 9 8945H). L3 cache: 64 MB on the Ryzen 9 3900 vs 16 MB on the Ryzen 9 8945H.

Feature	Ryzen 9 3900	Ryzen 9 8945H
Cores / Threads	12 / 24+50%	8 / 16
Boost Clock	4.3 GHz	5.2 GHz+21%
Base Clock	3.1 GHz	4 GHz+29%
L3 Cache	64 MB+300%	16 MB
L2 Cache	512 kB (per core)	8 MB+1500%
Process	7 nm, 12 nm	4 nm-43%
Architecture	Matisse (Zen 2) (2019−2020)	Hawk Point-HS (Zen 4) (2023−2024)
PassMark	30,588+1%	30,240
Cinebench R23 Multi	17,700+1%	17,500
Geekbench 6 Single	1,713	2,617+53%
Geekbench 6 Multi	10,983	12,662+15%

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Memory & Platform

The Ryzen 9 3900 uses the AM4 socket (PCIe 4.0), while the Ryzen 9 8945H uses FP7/FP7r2/FP8 (PCIe 4.0) — making them incompatible on the same motherboard. Maximum memory speed reaches DDR4-3200 on the Ryzen 9 3900 versus DDR5-5600 on the Ryzen 9 8945H — the Ryzen 9 8945H supports 75% faster memory, which can translate to measurable gains in memory-sensitive workloads. The Ryzen 9 8945H supports up to 256 GB of RAM compared to 128 GB — 100% more capacity for professional workloads. Both feature 2-channel memory with ECC support. PCIe lanes: 24 (Ryzen 9 3900) vs 20 (Ryzen 9 8945H) — the Ryzen 9 3900 offers 4 more lanes for additional GPUs or NVMe drives. Chipset compatibility: X570,B550,X470,B450 (Ryzen 9 3900) and FP7,FP7r2,FP8 (Ryzen 9 8945H).

Feature	Ryzen 9 3900	Ryzen 9 8945H
Socket	AM4	FP7/FP7r2/FP8
PCIe Generation	PCIe 4.0	PCIe 4.0
Max RAM Speed	DDR4-3200	DDR5-5600+75%
Max RAM Capacity	128 GB	256 GB+100%
RAM Channels	2	2
ECC Support	No	No
PCIe Lanes	24+20%	20

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Advanced Features

Only the Ryzen 9 3900 has an unlocked multiplier for overclocking — a significant advantage for enthusiasts seeking extra performance. Only the Ryzen 9 8945H supports AVX-512 instructions — important for machine learning and scientific applications. Both support AMD-V virtualization. The Ryzen 9 8945H includes integrated graphics (Radeon 780M), while the Ryzen 9 3900 requires a dedicated GPU. Primary use case: Ryzen 9 3900 targets Workstation Desktop (low power), Ryzen 9 8945H targets Gaming. Direct competitor: Ryzen 9 3900 rivals Core i9-9900; Ryzen 9 8945H rivals Core i9-13900H.