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 i5-2500K vs Core i5-6400T 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 i5-2500K vs Core i5-6400T: Pros, Cons & Final Verdict

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

Core i5-2500K

2011

Why buy it

✅+45.5% higher Cinebench R23 multi-core.

Trade-offs

❌Lower Geekbench single-core performance for gaming (684 vs 950).
❌Lower PassMark per dollar, at 18.4 vs 22.1 PassMark/$ ($225 MSRP vs $192 MSRP).
❌9400% higher power demand at 95W vs 1W.

Core i5-6400T

2015

Why buy it

✅+38.9% higher Geekbench single-core performance for gaming and desktop responsiveness.
✅Costs $33 less on MSRP ($192 MSRP vs $225 MSRP).
✅Delivers 20.1% more PassMark for each dollar spent, at 22.1 vs 18.4 PassMark/$ ($192 MSRP vs $225 MSRP).
✅Draws 1W instead of 95W, a 94W reduction.

Trade-offs

❌Lower Cinebench R23 multi-core (2,200 vs 3,200).

Quick Answers

So, is Core i5-6400T better than Core i5-2500K?

It depends on what you want from the system. For gaming, Core i5-6400T is ahead with a 0.7% average FPS lead across 50 shared CPU game tests in our data. For rendering, compiling, streaming, and heavier multitasking, Core i5-2500K pulls ahead with 45.5% better Cinebench R23 multi-core.

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

For streaming, content creation, and heavier multitasking, Core i5-2500K is the stronger fit. You are getting 45.5% better Cinebench R23 multi-core, backed by 4 cores and 4 threads.

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

Core i5-6400T is the better buy right now. Core i5-6400T comes in $33 cheaper on MSRP at $192 MSRP versus $225 MSRP, and it still gives you a 0.7% average FPS lead across 50 shared CPU game tests in our data. The compromise is that Core i5-2500K is still stronger for heavier multi-core work with 45.5% better Cinebench R23 multi-core. It is also 20.1% better value on MSRP (22.1 vs 18.4 PassMark/$), so you are getting the faster CPU without taking a value hit on paper.

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

Core i5-6400T makes more sense long term for 2026 and beyond. You are getting a newer CPU generation (2015 vs 2011). That makes it the safer long-term bet.

Core i5-2500K vs Core i5-6400T Technical Specifications

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

Core i5-2500K

The Core i5-2500K is manufactured by Intel. It was released in 9 January 2011 (14 years ago). It is based on the Sandy Bridge (2011−2013) architecture. It features 4 cores and 4 threads. Base frequency is 3.3 GHz, with boost up to 3.7 GHz. L3 cache: 6 MB (total). L2 cache: 256K (per core). Built on 32 nm process technology. Socket: LGA1155. Thermal design power (TDP): 95 Watt. Memory support: DDR3. Passmark benchmark score: 4,141 points. Launch price was $216.

Core i5-6400T

The Core i5-6400T is manufactured by Intel. It was released in 1 September 2015 (10 years ago). It is based on the Skylake (2015−2016) architecture. It features 4 cores and 4 threads. Base frequency is 2.2 GHz, with boost up to 2.8 GHz. L3 cache: 6 MB. L2 cache: 1 MB. Built on 14 nm process technology. Socket: LGA1151. Thermal design power (TDP): 35 Watt. Memory support: DDR3, DDR4. Passmark benchmark score: 4,243 points. Launch price was $192.

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Processing Power

Both the Core i5-2500K and Core i5-6400T share an identical 4-core/4-thread configuration. Boost clocks reach 3.7 GHz on the Core i5-2500K versus 2.8 GHz on the Core i5-6400T — a 27.7% clock advantage for the Core i5-2500K (base: 3.3 GHz vs 2.2 GHz). The Core i5-2500K uses the Sandy Bridge (2011−2013) architecture (32 nm), while the Core i5-6400T uses Skylake (2015−2016) (14 nm). In PassMark, the Core i5-2500K scores 4,141 against the Core i5-6400T's 4,243 — a 2.4% lead for the Core i5-6400T. Cinebench R23 multi-core: 3,200 vs 2,200 (37% advantage for the Core i5-2500K). Geekbench 6 single-core — the metric most relevant to gaming — records 684 vs 950, a 32.6% lead for the Core i5-6400T that directly translates to higher frame rates. Multi-core Geekbench: 2,032 vs 2,600 (24.5% advantage for the Core i5-6400T). L3 cache: 6 MB (total) on the Core i5-2500K vs 6 MB on the Core i5-6400T.

Feature	Core i5-2500K	Core i5-6400T
Cores / Threads	4 / 4	4 / 4
Boost Clock	3.7 GHz+32%	2.8 GHz
Base Clock	3.3 GHz+50%	2.2 GHz
L3 Cache	6 MB (total)	6 MB
L2 Cache	256K (per core)+25500%	1 MB
Process	32 nm	14 nm-56%
Architecture	Sandy Bridge (2011−2013)	Skylake (2015−2016)
PassMark	4,141	4,243+2%
Cinebench R23 Multi	3,200+45%	2,200
Geekbench 6 Single	684	950+39%
Geekbench 6 Multi	2,032	2,600+28%

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Memory & Platform

The Core i5-2500K uses the LGA1155 socket (PCIe 2.0), while the Core i5-6400T uses LGA1151 (PCIe 3.0) — making them incompatible on the same motherboard. Maximum memory speed reaches DDR3-1333 on the Core i5-2500K versus DDR4-2133 on the Core i5-6400T — the Core i5-6400T supports 60% faster memory, which can translate to measurable gains in memory-sensitive workloads. The Core i5-6400T supports up to 64 GB of RAM compared to 32 GB — 100% more capacity for professional workloads. Both feature 2-channel memory with ECC support. Both provide 16 PCIe lanes. Chipset compatibility: P67,Z68,Z77 (Core i5-2500K) and H110,B150,H170,Z170,Z270 (Core i5-6400T).

Feature	Core i5-2500K	Core i5-6400T
Socket	LGA1155	LGA1151
PCIe Generation	PCIe 2.0	PCIe 3.0+50%
Max RAM Speed	DDR3-1333	DDR4-2133+60%
Max RAM Capacity	32 GB	64 GB+100%
RAM Channels	2	2
ECC Support	No	No
PCIe Lanes	16	16

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Advanced Features

Only the Core i5-2500K has an unlocked multiplier for overclocking — a significant advantage for enthusiasts seeking extra performance. Virtualization support: VT-x (Core i5-2500K) vs VT-x, VT-d (Core i5-6400T). Both include integrated graphics — HD Graphics 3000 (Core i5-2500K) and HD 530 (Core i5-6400T) — useful as a fallback for troubleshooting or display output without a dedicated GPU. Primary use case: Core i5-2500K targets Gaming, Core i5-6400T targets Budget. Direct competitor: Core i5-2500K rivals FX-6300; Core i5-6400T rivals Core i3-7100.

Feature	Core i5-2500K	Core i5-6400T
Integrated GPU	Yes	Yes
IGPU Model	HD Graphics 3000	HD 530
Unlocked	Yes	No
AVX-512	No	No
Virtualization	VT-x	VT-x, VT-d
Target Use	Gaming	Budget

💰

Value Analysis

At launch, the Core i5-2500K was priced at $225, while the Core i5-6400T came in at $192. On launch pricing ($225 vs $192), Core i5-6400T was $33 cheaper. In terms of value on MSRP (PassMark points per dollar), the Core i5-2500K delivers 18.4 pts/$ vs 22.1 pts/$ for the Core i5-6400T — making the Core i5-6400T the 18.2% better value option.

Feature	Core i5-2500K	Core i5-6400T
MSRP	$225	$192-15%
Performance per Dollar	18.4	22.1+20%
Release Date	2011	2015

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