Core 2 Duo T6400 vs Xeon L5420

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 2 Duo T6400 vs Xeon L5420 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 2 Duo T6400 vs Xeon L5420: Pros, Cons & Final Verdict

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

Core 2 Duo T6400

2009

Why buy it

✅Draws 2W instead of 50W, a 48W reduction.

Trade-offs

❌Worse for gaming: lower average FPS than Xeon L5420 across 50 shared CPU benchmark tests.
❌Lower PassMark (2,115 vs 2,143).
❌Smaller total L3 cache (2 MB vs 12 MB).
❌Less compelling for workstation-style loads than Xeon L5420, which brings 4 cores / 4 threads.

Xeon L5420

2008

Why buy it

✅Better for gaming: +5.6% higher average FPS across 50 shared CPU benchmark tests.
✅+500% larger total L3 cache (12 MB vs 2 MB).
✅Better for workstations and heavier parallel workloads: 4 cores / 4 threads.

Trade-offs

❌2400% higher power demand at 50W vs 2W.

Quick Answers

So, is Xeon L5420 better than Core 2 Duo T6400?

Not really, because they are built for different jobs. Xeon L5420 makes more sense for workstation-style multi-core throughput, while Core 2 Duo T6400 is the more practical desktop choice for gaming, platform cost, and everyday use.

Which one is better for gaming?

If gaming is the priority, Xeon L5420 is the better pick. According to our tests, it delivers 5.6% 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 L5420 is the stronger fit. You are getting 1.3% better PassMark, backed by 4 cores and 4 threads. It also has the larger cache pool with 500% larger total L3 cache (12 MB vs 2 MB).

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

Xeon L5420 still makes the most sense overall. Xeon L5420 comes in at an unclear MSRP at unclear MSRP versus unclear MSRP, and it still gives you a 5.6% average FPS lead across 50 shared CPU game tests in our data.

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

Core 2 Duo T6400 makes more sense long term for 2026 and beyond. You are getting a newer CPU generation (2009 vs 2008). That makes it the safer long-term bet.

Core 2 Duo T6400 vs Xeon L5420 Technical Specifications

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

Core 2 Duo T6400

The Core 2 Duo T6400 is manufactured by Intel. It was released in 2008-01-01. It is based on the Penryn (2008−2011) architecture. It features 2 cores and 2 threads. Base frequency is 2 GHz, with boost up to 2 GHz. L3 cache: 2 MB L2 Cache. L2 cache: 2 MB. Built on 45 nm process technology. Socket: PGA478. Thermal design power (TDP): 35 Watt. Passmark benchmark score: 2,115 points. Launch price was $249.

Xeon L5420

The Xeon L5420 is manufactured by Intel. It was released in 25 March 2008 (17 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): 50 Watt. Memory support: DDR2, DDR3 Depends on motherboard. Passmark benchmark score: 2,143 points. Launch price was $380.

⚡

Processing Power

The Core 2 Duo T6400 packs 2 cores / 2 threads, while the Xeon L5420 offers 4 cores / 4 threads — the Xeon L5420 has 2 more cores. Boost clocks reach 2 GHz on the Core 2 Duo T6400 versus 2.5 GHz on the Xeon L5420 — a 22.2% clock advantage for the Xeon L5420 (base: 2 GHz vs 2.5 GHz). The Core 2 Duo T6400 uses the Penryn (2008−2011) architecture (45 nm), while the Xeon L5420 uses Harpertown (2007−2008) (45 nm). In PassMark, the Core 2 Duo T6400 scores 2,115 against the Xeon L5420's 2,143 — a 1.3% lead for the Xeon L5420. L3 cache: 2 MB L2 Cache on the Core 2 Duo T6400 vs 12 MB L2 Cache on the Xeon L5420.

Feature	Core 2 Duo T6400	Xeon L5420
Cores / Threads	2 / 2	4 / 4+100%
Boost Clock	2 GHz	2.5 GHz+25%
Base Clock	2 GHz	2.5 GHz+25%
L3 Cache	2 MB L2 Cache	12 MB L2 Cache+500%
L2 Cache	2 MB	6 MB (total)+200%
Process	45 nm	45 nm
Architecture	Penryn (2008−2011)	Harpertown (2007−2008)
PassMark	2,115	2,143+1%
Geekbench 6 Single	650	—
Geekbench 6 Multi	1,300	—

🧠

Memory & Platform

The Core 2 Duo T6400 uses the PGA478 socket (PCIe 1.1), while the Xeon L5420 uses LGA771 (PCIe 2.0) — making them incompatible on the same motherboard.