Xeon E5-2420 vs Xeon E5645

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 E5-2420 vs Xeon E5645 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 E5-2420 vs Xeon E5645: Pros, Cons & Final Verdict

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

Xeon E5-2420

2012

Why buy it

✅+1.4% higher PassMark.
✅+25% larger total L3 cache (15 MB vs 12 MB).

Trade-offs

❌18.8% higher power demand at 95W vs 80W.

Xeon E5645

2010

Why buy it

✅Draws 80W instead of 95W, a 15W reduction.

Trade-offs

❌Lower PassMark (4,942 vs 5,012).
❌Smaller total L3 cache (12 MB vs 15 MB).
❌Launch MSRP is still $294 MSRP, while Xeon E5-2420 mostly shows up through inconsistent older-market listings.

Quick Answers

So, is Xeon E5645 better than Xeon E5-2420?

It depends on what you want from the system. For gaming, Xeon E5645 is ahead with a 1.8% average FPS lead across 35 shared CPU game tests in our data. For rendering, compiling, streaming, and heavier multitasking, Xeon E5-2420 pulls ahead with 1.4% better PassMark. Xeon E5-2420 also has the bigger cache pool with 25% larger total L3 cache (15 MB vs 12 MB).

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

For streaming, content creation, and heavier multitasking, Xeon E5-2420 is the stronger fit. You are getting 1.4% better PassMark, backed by 6 cores and 12 threads. It also has the larger cache pool with 25% larger total L3 cache (15 MB vs 12 MB).

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

Xeon E5645 is the better buy right now. Xeon E5645 comes in at an unclear MSRP at $294 MSRP versus unclear MSRP, and it still gives you a 1.8% average FPS lead across 35 shared CPU game tests in our data. The compromise is that Xeon E5-2420 is still stronger for heavier multi-core work with 1.4% better PassMark. It is also 100.0% better value on MSRP (16.8 vs 0.0 PassMark/$), so you are getting the faster CPU without taking a value hit on paper.

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

Xeon E5-2420 makes more sense long term for 2026 and beyond. You are getting a newer CPU generation (2012 vs 2010), 25% larger total L3 cache (15 MB vs 12 MB), and more multi-core headroom with 6 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.

Xeon E5-2420 vs Xeon E5645 Technical Specifications

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

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.

Xeon E5645

The Xeon E5645 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 6 cores and 12 threads. Base frequency is 2.4 GHz, with boost up to 2.67 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: 4,942 points. Launch price was $294.

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Processing Power

Both the Xeon E5-2420 and Xeon E5645 share an identical 6-core/12-thread configuration. Boost clocks reach 2.4 GHz on the Xeon E5-2420 versus 2.67 GHz on the Xeon E5645 — a 10.7% clock advantage for the Xeon E5645 (base: 1.9 GHz vs 2.4 GHz). The Xeon E5-2420 uses the Sandy Bridge-EN (2012) architecture (32 nm), while the Xeon E5645 uses Westmere-EP (2010−2011) (32 nm). In PassMark, the Xeon E5-2420 scores 5,012 against the Xeon E5645's 4,942 — a 1.4% lead for the Xeon E5-2420. L3 cache: 15360 kB (total) on the Xeon E5-2420 vs 12 MB (total) on the Xeon E5645.

Feature	Xeon E5-2420	Xeon E5645
Cores / Threads	6 / 12	6 / 12
Boost Clock	2.4 GHz	2.67 GHz+11%
Base Clock	1.9 GHz	2.4 GHz+26%
L3 Cache	15360 kB (total)+25%	12 MB (total)
L2 Cache	256 kB (per core)	256 kB (per core)
Process	32 nm	32 nm
Architecture	Sandy Bridge-EN (2012)	Westmere-EP (2010−2011)
PassMark	5,012+1%	4,942

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Memory & Platform

The Xeon E5-2420 uses the LGA1356 socket (PCIe 2.0), while the Xeon E5645 uses LGA1366 (PCIe 5.0) — making them incompatible on the same motherboard.

Feature	Xeon E5-2420	Xeon E5645
Socket	LGA1356	LGA1366
PCIe Generation	PCIe 2.0	PCIe 5.0+150%
Max RAM Speed	—	DDR3-1333
Max RAM Capacity	—	288 GB
RAM Channels	—	3
ECC Support	—	Yes
PCIe Lanes	—	0