Core i7-6660U vs Xeon E5620

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.

Core i7-6660U vs Xeon E5620 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.

Core i7-6660U vs Xeon E5620: Pros, Cons & Final Verdict

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

Core i7-6660U

2016

Why buy it

✅+0.2% higher PassMark.
✅Draws 15W instead of 80W, a 65W reduction.

Trade-offs

❌Worse for gaming: lower average FPS than Xeon E5620 across 50 shared CPU benchmark tests.
❌Smaller total L3 cache (4 MB vs 12 MB).
❌Less compelling for workstation-style loads than Xeon E5620, which brings 4 cores / 8 threads.

Xeon E5620

2010

Why buy it

✅Better for gaming: +15.9% higher average FPS across 50 shared CPU benchmark tests.
✅+200% larger total L3 cache (12 MB vs 4 MB).
✅Better for workstations and heavier parallel workloads: 4 cores / 8 threads.

Trade-offs

❌Lower PassMark (3,621 vs 3,628).
❌433.3% higher power demand at 80W vs 15W.

Quick Answers

So, is Core i7-6660U better than Xeon E5620?

Not really, because they are built for different jobs. Xeon E5620 makes more sense for workstation-style multi-core throughput, while Core i7-6660U 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, Core i7-6660U is the stronger fit. You are getting 0.2% better PassMark, backed by 2 cores and 4 threads.

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

Core i7-6660U still makes the most sense overall. Core i7-6660U comes in at an unclear MSRP at unclear MSRP versus unclear MSRP, and it still gives you 0.2% better PassMark.

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

Core i7-6660U makes more sense long term for 2026 and beyond. You are getting a newer CPU generation (2016 vs 2010) and more multi-core headroom with 2 cores / 4 threads instead of 4/8. That extra compute headroom is more likely to matter as games, background tasks, and creator workloads get heavier.

Core i7-6660U vs Xeon E5620 Technical Specifications

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

Core i7-6660U

The Core i7-6660U is manufactured by Intel. It was released in 20 March 2016 (9 years ago). It is based on the Skylake (2015−2016) architecture. It features 2 cores and 4 threads. Base frequency is 2.4 GHz, with boost up to 3.4 GHz. L3 cache: 4 MB. L2 cache: 512 kB. Built on 14 nm process technology. Socket: BGA1356. Thermal design power (TDP): 15 Watt. Memory support: DDR4-2133, LPDDR3-1866, DDR3L-1600. Passmark benchmark score: 3,628 points. Launch price was $415.

Xeon E5620

The Xeon E5620 is manufactured by Intel. It was released in 16 March 2010 (15 years ago). It is based on the Westmere-EP (2010−2011) architecture. It features 4 cores and 8 threads. Base frequency is 2.4 GHz, with boost up to 2.66 GHz. L3 cache: 12 MB (total). L2 cache: 256 kB (per core). Built on 32 nm process technology. Socket: LGA1366. Thermal design power (TDP): 80 Watt. Memory support: DDR3. Passmark benchmark score: 3,621 points. Launch price was $35.

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Processing Power

The Core i7-6660U packs 2 cores / 4 threads, while the Xeon E5620 offers 4 cores / 8 threads — the Xeon E5620 has 2 more cores. Boost clocks reach 3.4 GHz on the Core i7-6660U versus 2.66 GHz on the Xeon E5620 — a 24.4% clock advantage for the Core i7-6660U (base: 2.4 GHz vs 2.4 GHz). The Core i7-6660U uses the Skylake (2015−2016) architecture (14 nm), while the Xeon E5620 uses Westmere-EP (2010−2011) (32 nm). In PassMark, the Core i7-6660U scores 3,628 against the Xeon E5620's 3,621 — a 0.2% lead for the Core i7-6660U. L3 cache: 4 MB on the Core i7-6660U vs 12 MB (total) on the Xeon E5620.

Feature	Core i7-6660U	Xeon E5620
Cores / Threads	2 / 4	4 / 8+100%
Boost Clock	3.4 GHz+28%	2.66 GHz
Base Clock	2.4 GHz	2.4 GHz
L3 Cache	4 MB	12 MB (total)+200%
L2 Cache	512 kB+100%	256 kB (per core)
Process	14 nm-56%	32 nm
Architecture	Skylake (2015−2016)	Westmere-EP (2010−2011)
PassMark	3,628	3,621

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Memory & Platform

The Core i7-6660U uses the BGA1356 socket (PCIe 3.0), while the Xeon E5620 uses LGA1366 (PCIe 2.0) — making them incompatible on the same motherboard.