Xeon E5420 vs Xeon X5355

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.

Xeon E5420 vs Xeon X5355 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.

Xeon E5420 vs Xeon X5355: Pros, Cons & Final Verdict

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

Xeon E5420

2007

Why buy it

✅+50% larger total L3 cache (12 MB vs 8 MB).
✅Draws 80W instead of 120W, a 40W reduction.
✅100+% more PCIe lanes (32 vs 0) for storage and expansion-heavy builds.

Trade-offs

❌Lower PassMark per dollar, at 0.3 vs 0.5 PassMark/$ ($7,214 MSRP vs $4,491 MSRP).

Xeon X5355

2006

Why buy it

✅Costs $2,723 less on MSRP ($4,491 MSRP vs $7,214 MSRP).
✅Delivers 60.2% more PassMark for each dollar spent, at 0.5 vs 0.3 PassMark/$ ($4,491 MSRP vs $7,214 MSRP).

Trade-offs

❌Lower PassMark (2,039 vs 2,044).
❌Smaller total L3 cache (8 MB vs 12 MB).
❌50% higher power demand at 120W vs 80W.

Quick Answers

So, is Xeon E5420 better than Xeon X5355?

Yes. Xeon E5420 is the better all-around CPU here. It gives you a 2.4% average FPS lead across 50 shared CPU game tests in our data, 0.2% better PassMark, and the stronger long-term platform, which is enough to make it the stronger overall pick.

Which one is better for gaming?

If gaming is the priority, Xeon E5420 is the better pick. According to our tests, it delivers 2.4% 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, Xeon E5420 is the stronger fit. You are getting 0.2% better PassMark, backed by 4 cores and 4 threads. It also has the larger cache pool with 50% larger total L3 cache (12 MB vs 8 MB).

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

Xeon E5420 is still the faster CPU overall, but Xeon X5355 is easier to justify if budget matters more than peak performance. Xeon E5420 comes in 60.6% more expensive on MSRP at $7,214 MSRP versus $4,491 MSRP, and it still gives you a 2.4% average FPS lead across 50 shared CPU game tests in our data. Xeon X5355 is also 60.2% better value on MSRP (0.5 vs 0.3 PassMark/$), which is why it can still make sense for tighter-budget builds on paper.

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

Xeon E5420 makes more sense long term for 2026 and beyond. You are getting a newer CPU generation (2007 vs 2006), 50% larger total L3 cache (12 MB vs 8 MB), and more multi-core headroom with 4 cores / 4 threads instead of 4/4. That extra compute headroom is more likely to matter as games, background tasks, and creator workloads get heavier.

Xeon E5420 vs Xeon X5355 Technical Specifications

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

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.

Xeon X5355

The Xeon X5355 is manufactured by Intel. It was released in 14 November 2006 (19 years ago). It is based on the Clovertown (2006−2007) architecture. It features 4 cores and 4 threads. Base frequency is 2.66 GHz, with boost up to 0.67 GHz. L3 cache: 8 MB L2 Cache. L2 cache: 4 MB (total). Built on 65 nm process technology. Socket: LGA771. Thermal design power (TDP): 120 Watt. Memory support: DDR2, DDR3 Depends on motherboard. Passmark benchmark score: 2,039 points. Launch price was $1,172.

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Processing Power

Both the Xeon E5420 and Xeon X5355 share an identical 4-core/4-thread configuration. Boost clocks reach 2.5 GHz on the Xeon E5420 versus 0.67 GHz on the Xeon X5355 — a 115.5% clock advantage for the Xeon E5420 (base: 2.5 GHz vs 2.66 GHz). The Xeon E5420 uses the Harpertown (2007−2008) architecture (45 nm), while the Xeon X5355 uses Clovertown (2006−2007) (65 nm). In PassMark, the Xeon E5420 scores 2,044 against the Xeon X5355's 2,039 — a 0.2% lead for the Xeon E5420. L3 cache: 12 MB L2 Cache on the Xeon E5420 vs 8 MB L2 Cache on the Xeon X5355.

Feature	Xeon E5420	Xeon X5355
Cores / Threads	4 / 4	4 / 4
Boost Clock	2.5 GHz+273%	0.67 GHz
Base Clock	2.5 GHz	2.66 GHz+6%
L3 Cache	12 MB L2 Cache+50%	8 MB L2 Cache
L2 Cache	6 MB (total)+50%	4 MB (total)
Process	45 nm-31%	65 nm
Architecture	Harpertown (2007−2008)	Clovertown (2006−2007)
PassMark	2,044	2,039
Geekbench 6 Single	314	—
Geekbench 6 Multi	881	—

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Memory & Platform

Both processors use the LGA771 socket with PCIe 2.0.

Feature	Xeon E5420	Xeon X5355
Socket	LGA771	LGA771
PCIe Generation	PCIe 2.0	PCIe 2.0
Max RAM Speed	DDR2-667	—
Max RAM Capacity	32 GB	—
RAM Channels	4	—
ECC Support	Yes	—
PCIe Lanes	32	—

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Advanced Features

Virtualization: Yes (Xeon E5420) / not specified (Xeon X5355).

Feature	Xeon E5420	Xeon X5355
Integrated GPU	No	—
AVX-512	No	—
Virtualization	Yes	—

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Value Analysis

At launch, the Xeon E5420 was priced at $7214, while the Xeon X5355 came in at $4491. On launch pricing ($7214 vs $4491), Xeon X5355 was $2723 cheaper. In terms of value on MSRP (PassMark points per dollar), the Xeon E5420 delivers 0.3 pts/$ vs 0.5 pts/$ for the Xeon X5355 — making the Xeon X5355 the 46.3% better value option.

Feature	Xeon E5420	Xeon X5355
MSRP	$7214	$4491-38%
Performance per Dollar	0.3	0.5+67%
Release Date	2007	2006

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