Celeron B815 vs Core 2 Duo T6400

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 B815 vs Core 2 Duo T6400 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 B815 vs Core 2 Duo T6400: Pros, Cons & Final Verdict

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

Celeron B815

2012

Why buy it

✅100+% more PCIe lanes (16 vs 0) for storage and expansion-heavy builds.
✅Integrated graphics onboard with HD Graphics (Sandy Bridge), while Core 2 Duo T6400 needs a discrete GPU.

Trade-offs

❌Lower PassMark (2,093 vs 2,115).
❌Launch MSRP is still $86 MSRP, while Core 2 Duo T6400 mostly shows up through inconsistent older-market listings.

Core 2 Duo T6400

2009

Why buy it

Trade-offs

❌No integrated graphics, while Celeron B815 can still boot and troubleshoot without a discrete GPU.

Quick Answers

So, is Core 2 Duo T6400 better than Celeron B815?

Yes. Core 2 Duo T6400 is the better all-around CPU here. It gives you a 0.5% average FPS lead across 50 shared CPU game tests in our data and 1.1% better PassMark, which is enough to make it the stronger overall pick.

Which one is better for gaming?

If gaming is the priority, Core 2 Duo T6400 is the better pick. According to our tests, it delivers 0.5% 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, Core 2 Duo T6400 is the stronger fit. You are getting 1.1% better PassMark, backed by 2 cores and 2 threads.

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

Core 2 Duo T6400 is still the much better call for a fresh build. Core 2 Duo T6400 comes in at an unclear MSRP at unclear MSRP versus $86 MSRP, and it still gives you a 0.5% average FPS lead across 50 shared CPU game tests in our data. Celeron B815 only looks stronger on raw value math because it is extremely cheap, but that usually means used-market pricing on an obsolete 2012 platform. Even with 100.0% better value on paper (24.3 vs 0.0 PassMark/$), it really only makes sense as a cheap stopgap or a niche existing-platform option for someone already on PGA988.

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

Celeron B815 makes more sense long term for 2026 and beyond. You are getting a newer CPU generation (2012 vs 2009). That makes it the safer long-term bet.

Celeron B815 vs Core 2 Duo T6400 Technical Specifications

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

Celeron B815

The Celeron B815 is manufactured by Intel. It was released in 1 January 2012 (13 years ago). It is based on the Sandy Bridge (2011−2013) architecture. It features 2 cores and 2 threads. Base frequency is 1.6 GHz, with boost up to 1.6 GHz. L3 cache: 2 MB (total). L2 cache: 256K (per core). Built on 32 nm process technology. Socket: PGA988. Thermal design power (TDP): 35 Watt. Memory support: DDR3. Passmark benchmark score: 2,093 points. Launch price was $86.

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.

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Processing Power

Both the Celeron B815 and Core 2 Duo T6400 share an identical 2-core/2-thread configuration. Boost clocks reach 1.6 GHz on the Celeron B815 versus 2 GHz on the Core 2 Duo T6400 — a 22.2% clock advantage for the Core 2 Duo T6400 (base: 1.6 GHz vs 2 GHz). The Celeron B815 uses the Sandy Bridge (2011−2013) architecture (32 nm), while the Core 2 Duo T6400 uses Penryn (2008−2011) (45 nm). In PassMark, the Celeron B815 scores 2,093 against the Core 2 Duo T6400's 2,115 — a 1% lead for the Core 2 Duo T6400. L3 cache: 2 MB (total) on the Celeron B815 vs 2 MB L2 Cache on the Core 2 Duo T6400.

Feature	Celeron B815	Core 2 Duo T6400
Cores / Threads	2 / 2	2 / 2
Boost Clock	1.6 GHz	2 GHz+25%
Base Clock	1.6 GHz	2 GHz+25%
L3 Cache	2 MB (total)	2 MB L2 Cache
L2 Cache	256K (per core)+12700%	2 MB
Process	32 nm-29%	45 nm
Architecture	Sandy Bridge (2011−2013)	Penryn (2008−2011)
PassMark	2,093	2,115+1%
Geekbench 6 Single	—	650
Geekbench 6 Multi	—	1,300

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Memory & Platform

The Celeron B815 uses the PGA988 socket (PCIe 2.0), while the Core 2 Duo T6400 uses PGA478 (PCIe 1.1) — making them incompatible on the same motherboard. Maximum memory speed reaches DDR3-1333 on the Celeron B815 versus DDR2-800 on the Core 2 Duo T6400 — the Celeron B815 supports 66.6% faster memory, which can translate to measurable gains in memory-sensitive workloads. The Celeron B815 supports up to 16 GB of RAM compared to 8 GB — 100% more capacity for professional workloads. Both feature 2-channel memory with ECC support. PCIe lanes: 16 (Celeron B815) vs 0 (Core 2 Duo T6400) — the Celeron B815 offers 16 more lanes for additional GPUs or NVMe drives. Chipset compatibility: HM65,HM67,QM67,QM77 (Celeron B815) and Intel GM45,Intel PM45 (Core 2 Duo T6400).

Feature	Celeron B815	Core 2 Duo T6400
Socket	PGA988	PGA478
PCIe Generation	PCIe 2.0+82%	PCIe 1.1
Max RAM Speed	DDR3-1333+67%	DDR2-800
Max RAM Capacity	16 GB+100%	8 GB
RAM Channels	2	2
ECC Support	No	No
PCIe Lanes	16	0

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Advanced Features

Neither processor supports overclocking. Virtualization support: VT-x (Celeron B815) vs No (Core 2 Duo T6400). The Celeron B815 includes integrated graphics (HD Graphics (Sandy Bridge)), while the Core 2 Duo T6400 requires a dedicated GPU. Primary use case: Celeron B815 targets Budget, Core 2 Duo T6400 targets Mobile. Direct competitor: Celeron B815 rivals Pentium 967.