Atom C3858 vs Xeon E5-2420

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.

Atom C3858 vs Xeon E5-2420 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.

Atom C3858 vs Xeon E5-2420: Pros, Cons & Final Verdict

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

Atom C3858

2017

Why buy it

✅Better for gaming: +14.3% higher average FPS across 22 shared CPU benchmark tests.
✅Draws 25W instead of 95W, a 70W reduction.
✅100+% more PCIe lanes (12 vs 0) for storage and expansion-heavy builds.

Trade-offs

❌Smaller total L3 cache (12 MB vs 15 MB).

Xeon E5-2420

2012

Why buy it

✅+25% larger total L3 cache (15 MB vs 12 MB).

Trade-offs

❌Worse for gaming: lower average FPS than Atom C3858 across 22 shared CPU benchmark tests.
❌Lower PassMark (5,012 vs 5,040).
❌280% higher power demand at 95W vs 25W.

Quick Answers

So, is Atom C3858 better than Xeon E5-2420?

Not really, because they are built for different jobs. Xeon E5-2420 makes more sense for workstation-style multi-core throughput, while Atom C3858 is the more practical desktop choice for gaming, platform cost, and everyday use.

Which one is better for gaming?

If gaming is the priority, Atom C3858 is the better pick. According to our tests, it delivers 14.3% more average FPS across 22 shared CPU game tests.

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

For streaming, content creation, and heavier multitasking, Atom C3858 is the stronger fit. You are getting 0.6% better PassMark, backed by 12 cores and 12 threads.

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

Atom C3858 still makes the most sense overall. Atom C3858 comes in at an unclear MSRP at unclear MSRP versus unclear MSRP, and it still gives you a 14.3% average FPS lead across 22 shared CPU game tests in our data.

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

Atom C3858 makes more sense long term for 2026 and beyond. You are getting a newer CPU generation (2017 vs 2012) and more multi-core headroom with 12 cores / 12 threads instead of 6/12. That extra compute headroom is more likely to matter as games, background tasks, and creator workloads get heavier.

Atom C3858 vs Xeon E5-2420 Technical Specifications

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

Atom C3858

The Atom C3858 is manufactured by Intel. It was released in 15 August 2017 (8 years ago). It is based on the Goldmont (2016−2017) architecture. It features 12 cores and 12 threads. Base frequency is 2 GHz, with boost up to 2 GHz. L3 cache: 12 MB. L2 cache: 12 MB. Built on 14 nm process technology. Socket: FCBGA1310. Thermal design power (TDP): 25 Watt. Memory support: DDR4: 2400. Passmark benchmark score: 5,040 points. Launch price was $332.

Xeon E5-2420

The Xeon E5-2420 is manufactured by Intel. It was released in 14 May 2012 (13 years ago). It is based on the Sandy Bridge-EN (2012) architecture. It features 6 cores and 12 threads. Base frequency is 1.9 GHz, with boost up to 2.4 GHz. L3 cache: 15360 kB (total). L2 cache: 256 kB (per core). Built on 32 nm process technology. Socket: LGA1356. Thermal design power (TDP): 95 Watt. Memory support: DDR3. Passmark benchmark score: 5,012 points. Launch price was $390.

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Processing Power

The Atom C3858 packs 12 cores / 12 threads, while the Xeon E5-2420 offers 6 cores / 12 threads — the Atom C3858 has 6 more cores. Boost clocks reach 2 GHz on the Atom C3858 versus 2.4 GHz on the Xeon E5-2420 — a 18.2% clock advantage for the Xeon E5-2420 (base: 2 GHz vs 1.9 GHz). The Atom C3858 uses the Goldmont (2016−2017) architecture (14 nm), while the Xeon E5-2420 uses Sandy Bridge-EN (2012) (32 nm). In PassMark, the Atom C3858 scores 5,040 against the Xeon E5-2420's 5,012 — a 0.6% lead for the Atom C3858. L3 cache: 12 MB on the Atom C3858 vs 15360 kB (total) on the Xeon E5-2420.

Feature	Atom C3858	Xeon E5-2420
Cores / Threads	12 / 12+100%	6 / 12
Boost Clock	2 GHz	2.4 GHz+20%
Base Clock	2 GHz+5%	1.9 GHz
L3 Cache	12 MB	15360 kB (total)+25%
L2 Cache	12 MB+4700%	256 kB (per core)
Process	14 nm-56%	32 nm
Architecture	Goldmont (2016−2017)	Sandy Bridge-EN (2012)
PassMark	5,040	5,012

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Memory & Platform

The Atom C3858 uses the FCBGA1310 socket (PCIe 3.0), while the Xeon E5-2420 uses LGA1356 (PCIe 2.0) — making them incompatible on the same motherboard.

Feature	Atom C3858	Xeon E5-2420
Socket	FCBGA1310	LGA1356
PCIe Generation	PCIe 3.0+50%	PCIe 2.0
Max RAM Speed	DDR4-2400	—
Max RAM Capacity	256 GB	—
RAM Channels	2	—
ECC Support	Yes	—
PCIe Lanes	12	—