Celeron M 585 vs Xeon E5420

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 M 585 vs Xeon E5420 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 M 585 vs Xeon E5420: Pros, Cons & Final Verdict

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

Celeron M 585

2008

Why buy it

✅+0.9% higher PassMark.
✅Draws 1W instead of 80W, a 79W reduction.

Trade-offs

❌Less compelling for workstation-style loads than Xeon E5420, which brings 4 cores / 4 threads and 32 PCIe lanes.

Xeon E5420

2007

Why buy it

✅Better for workstations and heavier parallel workloads: 4 cores / 4 threads, plus 32 PCIe lanes vs 0.
✅100+% more PCIe lanes (32 vs 0) for storage and expansion-heavy builds.

Trade-offs

❌Lower PassMark (2,044 vs 2,062).
❌Launch MSRP is still $7,214 MSRP, while Celeron M 585 mostly shows up through inconsistent older-market listings.
❌7900% higher power demand at 80W vs 1W.

Quick Answers

So, is Celeron M 585 better than Xeon E5420?

Not really, because they are built for different jobs. Xeon E5420 makes more sense for workstation-style multi-core throughput, while Celeron M 585 is the more practical desktop choice for gaming, platform cost, and everyday use.

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

For streaming, content creation, and heavier multitasking, Celeron M 585 is the stronger fit. You are getting 0.9% better PassMark, backed by 1 cores and 1 threads.

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

Celeron M 585 is still the faster CPU overall, but Xeon E5420 is easier to justify if budget matters more than peak performance. Celeron M 585 comes in at an unclear MSRP at unclear MSRP versus $7,214 MSRP, and it still gives you 0.9% better PassMark. The compromise is that Xeon E5420 is still the better pure gaming CPU with a 0.1% average FPS lead across 50 shared CPU game tests in our data. Xeon E5420 is also 100.0% better value on MSRP (0.3 vs 0.0 PassMark/$), which is why it can still make sense for tighter-budget builds on paper.

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

Celeron M 585 makes more sense long term for 2026 and beyond. You are getting a newer CPU generation (2008 vs 2007) and more multi-core headroom with 1 cores / 1 threads instead of 4/4. That extra compute headroom is more likely to matter as games, background tasks, and creator workloads get heavier.

Celeron M 585 vs Xeon E5420 Technical Specifications

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

Celeron M 585

The Celeron M 585 is manufactured by Intel. It was released in 20 August 2008 (17 years ago). It is based on the Merom (2006−2008) architecture. It features 1 cores and 1 threads. Max frequency: 2.16 GHz. L2 cache: 1 MB. Built on 65 nm process technology. Socket: PGA478. Thermal design power (TDP): 1 MB. Passmark benchmark score: 2,062 points. Launch price was $70.

Xeon E5420

The Xeon E5420 is manufactured by Intel. It was released in 11 November 2007 (18 years ago). It is based on the Harpertown (2007−2008) architecture. It features 4 cores and 4 threads. Base frequency is 2.5 GHz, with boost up to 2.5 GHz. L3 cache: 12 MB L2 Cache. L2 cache: 6 MB (total). Built on 45 nm process technology. Socket: LGA771. Thermal design power (TDP): 80 Watt. Memory support: DDR2, DDR3 Depends on motherboard. Passmark benchmark score: 2,044 points. Launch price was $316.

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Processing Power

The Celeron M 585 packs 1 cores / 1 threads, while the Xeon E5420 offers 4 cores / 4 threads — the Xeon E5420 has 3 more cores. Boost clocks reach 2.16 GHz on the Celeron M 585 versus 2.5 GHz on the Xeon E5420 — a 14.6% clock advantage for the Xeon E5420. The Celeron M 585 uses the Merom (2006−2008) architecture (65 nm), while the Xeon E5420 uses Harpertown (2007−2008) (45 nm). In PassMark, the Celeron M 585 scores 2,062 against the Xeon E5420's 2,044 — a 0.9% lead for the Celeron M 585.

Feature	Celeron M 585	Xeon E5420
Cores / Threads	1 / 1	4 / 4+300%
Boost Clock	2.16 GHz	2.5 GHz+16%
Base Clock	—	2.5 GHz
L3 Cache	—	12 MB L2 Cache
L2 Cache	1 MB	6 MB (total)+500%
Process	65 nm	45 nm-31%
Architecture	Merom (2006−2008)	Harpertown (2007−2008)
PassMark	2,062	2,044
Geekbench 6 Single	—	314
Geekbench 6 Multi	—	881

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Memory & Platform

The Celeron M 585 uses the PGA478 socket (PCIe 1.1), while the Xeon E5420 uses LGA771 (PCIe 2.0) — making them incompatible on the same motherboard. Maximum memory speed reaches 800 on the Celeron M 585 versus DDR2-667 on the Xeon E5420 — the Celeron M 585 supports 19.9% faster memory, which can translate to measurable gains in memory-sensitive workloads. The Xeon E5420 supports up to 32 GB of RAM compared to 4 GB — 700% more capacity for professional workloads. Memory channels: 2 (Celeron M 585) vs 4 (Xeon E5420). PCIe lanes: 0 (Celeron M 585) vs 32 (Xeon E5420) — the Xeon E5420 offers 32 more lanes for additional GPUs or NVMe drives. Chipset compatibility: GL40,GM45 (Celeron M 585) and Intel 5000P,Intel 5100,Intel 5400 (Xeon E5420).

Feature	Celeron M 585	Xeon E5420
Socket	PGA478	LGA771
PCIe Generation	PCIe 1.1	PCIe 2.0+82%
Max RAM Speed	800+20%	DDR2-667
Max RAM Capacity	4 GB	32 GB+700%
RAM Channels	2	4+100%
ECC Support	No	Yes
PCIe Lanes	0	32