Athlon 64 X2 4000+ vs Phenom X3 8400

Athlon 64 X2 4000+ vs Phenom X3 8400 Performance Spectrum

Athlon 64 X2 4000+

2 / 2

1,175

+0.9%

Ryzen Threadripper PRO 3955WX

Ryzen Threadripper PRO 7955WX

Ryzen Threadripper 3990X

Phenom X3 8400

3 / 3

1,164

0.0%

Ryzen Threadripper PRO 3955WX

Ryzen Threadripper PRO 7955WX

Ryzen Threadripper 3990X

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.

Athlon 64 X2 4000+ vs Phenom X3 8400 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.

Athlon 64 X2 4000+ vs Phenom X3 8400: Pros, Cons & Final Verdict

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

Athlon 64 X2 4000+

2006

Why buy it

✅+0.9% higher PassMark.
✅Draws 89W instead of 95W, a 6W reduction.
✅Includes a boxed cooler (Stock Cooler), unlike Phenom X3 8400.

Trade-offs

❌Launch MSRP is still $328 MSRP, while Phenom X3 8400 mostly shows up through inconsistent older-market listings.

Phenom X3 8400

2008

Why buy it

Trade-offs

❌Lower PassMark (1,164 vs 1,175).
❌No boxed cooler included, unlike Athlon 64 X2 4000+.

Quick Answers

So, is Athlon 64 X2 4000+ better than Phenom X3 8400?

It depends on what you want from the system. For gaming, Phenom X3 8400 is ahead with a 2.1% average FPS lead across 47 shared CPU game tests in our data. For rendering, compiling, streaming, and heavier multitasking, Athlon 64 X2 4000+ pulls ahead with 0.9% better PassMark.

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

For streaming, content creation, and heavier multitasking, Athlon 64 X2 4000+ is the stronger fit. You are getting 0.9% better PassMark, backed by 2 cores and 2 threads.

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

Athlon 64 X2 4000+ is the better buy right now. Athlon 64 X2 4000+ comes in at an unclear MSRP at $328 MSRP versus unclear MSRP, and it still gives you 0.9% better PassMark. The compromise is that Phenom X3 8400 is still the better pure gaming CPU with a 2.1% average FPS lead across 47 shared CPU game tests in our data. It is also 100.0% better value on MSRP (3.6 vs 0.0 PassMark/$), so you are getting the faster CPU without taking a value hit on paper.

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

Phenom X3 8400 makes more sense long term for 2026 and beyond. You are getting a newer CPU generation (2008 vs 2006). That makes it the safer long-term bet.

Athlon 64 X2 4000+ vs Phenom X3 8400 Technical Specifications

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

Athlon 64 X2 4000+

The Athlon 64 X2 4000+ is manufactured by AMD. It was released in 2009-01-01. It is based on the Windsor (2006−2007) architecture. It features 2 cores and 2 threads. Max frequency: 2 GHz. L3 cache: 0 kB. L2 cache: 512K. Built on 90 nm process technology. Socket: AM2. Thermal design power (TDP): 89 Watt. Passmark benchmark score: 1,175 points. Launch price was $149.

Phenom X3 8400

The Phenom X3 8400 is manufactured by AMD. It was released in 2009-01-01. It is based on the Toliman (2008) architecture. It features 3 cores and 3 threads. Max frequency: 2.1 GHz. L3 cache: 2 MB (total). L2 cache: 512 kB (per core). Built on 65 nm process technology. Socket: AM2+. Thermal design power (TDP): 95 Watt. Passmark benchmark score: 1,164 points. Launch price was $149.

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Processing Power

The Athlon 64 X2 4000+ packs 2 cores / 2 threads, while the Phenom X3 8400 offers 3 cores / 3 threads — the Phenom X3 8400 has 1 more core. Boost clocks reach 2 GHz on the Athlon 64 X2 4000+ versus 2.1 GHz on the Phenom X3 8400 — a 4.9% clock advantage for the Phenom X3 8400. The Athlon 64 X2 4000+ uses the Windsor (2006−2007) architecture (90 nm), while the Phenom X3 8400 uses Toliman (2008) (65 nm). In PassMark, the Athlon 64 X2 4000+ scores 1,175 against the Phenom X3 8400's 1,164 — a 0.9% lead for the Athlon 64 X2 4000+. L3 cache: 0 kB on the Athlon 64 X2 4000+ vs 2 MB (total) on the Phenom X3 8400.

Feature	Athlon 64 X2 4000+	Phenom X3 8400
Cores / Threads	2 / 2	3 / 3+50%
Boost Clock	2 GHz	2.1 GHz+5%
L3 Cache	0 kB	2 MB (total)
L2 Cache	512K	512 kB (per core)
Process	90 nm	65 nm-28%
Architecture	Windsor (2006−2007)	Toliman (2008)
PassMark	1,175	1,164
Geekbench 6 Single	195	—
Geekbench 6 Multi	380	—

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Memory & Platform

The Athlon 64 X2 4000+ uses the AM2 socket (PCIe 1.1), while the Phenom X3 8400 uses AM2+ (PCIe 2.0) — making them incompatible on the same motherboard.

Feature	Athlon 64 X2 4000+	Phenom X3 8400
Socket	AM2	AM2+
PCIe Generation	PCIe 1.1	PCIe 2.0+82%
Max RAM Speed	DDR2-800	—
Max RAM Capacity	4 GB	—
RAM Channels	2	—
ECC Support	No	—
PCIe Lanes	0	—

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Advanced Features

Virtualization: AMD-V (Athlon 64 X2 4000+) / not specified (Phenom X3 8400). Primary use case: Athlon 64 X2 4000+ targets Legacy Desktop.