Celeron 3855U vs Phenom II X2 B55

Celeron 3855U vs Phenom II X2 B55 Performance Spectrum

Celeron 3855U

2 / 2

1,215

0.0%

1,222

+0.6%

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.

Celeron 3855U vs Phenom II X2 B55 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.

Celeron 3855U vs Phenom II X2 B55: Pros, Cons & Final Verdict

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

Celeron 3855U

2015

Why buy it

✅Draws 15W instead of 80W, a 65W reduction.
✅100+% more PCIe lanes (10 vs 0) for storage and expansion-heavy builds.
✅Integrated graphics onboard with Intel HD Graphics 510, while Phenom II X2 B55 needs a discrete GPU.

Trade-offs

❌Worse for gaming: lower average FPS than Phenom II X2 B55 across 50 shared CPU benchmark tests.
❌Lower PassMark (1,215 vs 1,222).
❌Smaller total L3 cache (2 MB vs 6 MB).

Phenom II X2 B55

2009

Why buy it

✅Better for gaming: +3.0% higher average FPS across 50 shared CPU benchmark tests.
✅+200% larger total L3 cache (6 MB vs 2 MB).

Trade-offs

❌433.3% higher power demand at 80W vs 15W.
❌No integrated graphics, while Celeron 3855U can still boot and troubleshoot without a discrete GPU.

Quick Answers

So, is Phenom II X2 B55 better than Celeron 3855U?

Yes. Phenom II X2 B55 is the better all-around CPU here. It gives you a 3.0% average FPS lead across 50 shared CPU game tests in our data and 0.6% better PassMark, which is enough to make it the stronger overall pick.

Which one is better for gaming?

If gaming is the priority, Phenom II X2 B55 is the better pick. According to our tests, it delivers 3.0% more average FPS across 50 shared CPU game tests.

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

For streaming, content creation, and heavier multitasking, Phenom II X2 B55 is the stronger fit. You are getting 0.6% better PassMark, backed by 2 cores and 2 threads. It also has the larger cache pool with 200% larger total L3 cache (6 MB vs 2 MB).

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

Phenom II X2 B55 still makes the most sense overall. Phenom II X2 B55 comes in at an unclear MSRP at unclear MSRP versus unclear MSRP, and it still gives you a 3.0% average FPS lead across 50 shared CPU game tests in our data.

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

Celeron 3855U makes more sense long term for 2026 and beyond. You are getting a newer CPU generation (2015 vs 2009). That makes it the safer long-term bet.

Celeron 3855U vs Phenom II X2 B55 Technical Specifications

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

Celeron 3855U

The Celeron 3855U is manufactured by Intel. It was released in 15 August 2015 (10 years ago). It is based on the Skylake (2015−2016) architecture. It features 2 cores and 2 threads. Base frequency is 1.6 GHz, with boost up to 1.6 GHz. L3 cache: 2 MB. L2 cache: 512 kB. Built on 14 nm process technology. Socket: BGA1356. Thermal design power (TDP): 15 Watt. Memory support: DDR4-1866/2133, LPDDR3-1600/1866, DDR3L-1333/1600. Passmark benchmark score: 1,215 points. Launch price was $107.

Phenom II X2 B55

The Phenom II X2 B55 is manufactured by AMD. It was released in 1 October 2009 (16 years ago). It is based on the Callisto (2009−2010) architecture. It features 2 cores and 2 threads. Base frequency is 3 GHz, with boost up to 3 GHz. L3 cache: 6 MB (total). L2 cache: 512 kB (per core). Built on 45 nm process technology. Socket: AM3. Thermal design power (TDP): 80 Watt. Memory support: DDR3. Passmark benchmark score: 1,222 points. Launch price was $48.

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Processing Power

Both the Celeron 3855U and Phenom II X2 B55 share an identical 2-core/2-thread configuration. Boost clocks reach 1.6 GHz on the Celeron 3855U versus 3 GHz on the Phenom II X2 B55 — a 60.9% clock advantage for the Phenom II X2 B55 (base: 1.6 GHz vs 3 GHz). The Celeron 3855U uses the Skylake (2015−2016) architecture (14 nm), while the Phenom II X2 B55 uses Callisto (2009−2010) (45 nm). In PassMark, the Celeron 3855U scores 1,215 against the Phenom II X2 B55's 1,222 — a 0.6% lead for the Phenom II X2 B55. L3 cache: 2 MB on the Celeron 3855U vs 6 MB (total) on the Phenom II X2 B55.

Feature	Celeron 3855U	Phenom II X2 B55
Cores / Threads	2 / 2	2 / 2
Boost Clock	1.6 GHz	3 GHz+87%
Base Clock	1.6 GHz	3 GHz+87%
L3 Cache	2 MB	6 MB (total)+200%
L2 Cache	512 kB	512 kB (per core)
Process	14 nm-69%	45 nm
Architecture	Skylake (2015−2016)	Callisto (2009−2010)
PassMark	1,215	1,222
Geekbench 6 Single	361	—
Geekbench 6 Multi	632	—

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Memory & Platform

The Celeron 3855U uses the BGA1356 socket (PCIe 3.0), while the Phenom II X2 B55 uses AM3 (PCIe 2.0) — making them incompatible on the same motherboard.

Feature	Celeron 3855U	Phenom II X2 B55
Socket	BGA1356	AM3
PCIe Generation	PCIe 3.0+50%	PCIe 2.0
Max RAM Speed	DDR4 2133 MHz	—
Max RAM Capacity	32 GB	—
RAM Channels	2	—
ECC Support	No	—
PCIe Lanes	10	—

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Advanced Features

Virtualization: true (Celeron 3855U) / not specified (Phenom II X2 B55). The Celeron 3855U includes integrated graphics (Intel HD Graphics 510), while the Phenom II X2 B55 requires a dedicated GPU. Primary use case: Celeron 3855U targets Budget. Direct competitor: Celeron 3855U rivals Pentium 3825U.