15 specifications

Intel Core i5-6600 vs Intel Core i5-6600K

On the specifications we can verify, the Intel Core i5-6600 and the Intel Core i5-6600K are closely matched. Which one is faster on your desk depends on cooling and sustained behaviour rather than on anything printed here.

10 specifications · 1 with a higher side

Full specifications

Intel Core i5-6600

Intel · Core 6th generation · Desktop

Full specifications

Intel Core i5-6600K

Intel · Core 6th generation · Desktop

Cores and clocks

Cores

Threads

Base clock

3.3 GHz

3.5 GHz

Boost clock

3.9 GHz

Cache and power

L3 cache

6 MB

TDP

65 W

91 W

Platform

Socket

FCLGA1151

Process

14 nm

Integrated graphics

Intel HD Graphics 530

Launched

Q3'15 (quarter)

A check marks the higher figure only on rows where higher is unambiguously better. Rows without one are not ties; they are specifications where “better” has no meaning.

Reading the table

What the difference means.

The same generation

Both are Core 6th generation parts, so their figures can be read against each other directly: the same kind of core, the same memory support, the same platform. The differences in the table are the whole difference.

Power and cooling

The Core i5-6600K is rated at 91 W against 65 W. The rating is the heat the cooler has to move for the chip to hold its speed, and modern chips draw well above it in short bursts. A competent tower cooler suits the Core i5-6600K; the Core i5-6600 is easier to keep quiet and fits smaller cases. A chip whose cooling falls short does not fail. It slows down, and it does so after the first minute, which is why short benchmarks miss it.

Platform

Both use the FCLGA1151 socket, so one can replace the other on the same motherboard. Check the board maker's support list first: an older board often needs a firmware update before it recognises a newer chip.

Which to pick, on paper

A quiet or compact build: Core i5-6600; 65 W against 91 W: less heat to move, so a smaller cooler and slower fans.
Upgrading without a new motherboard: Either; Same FCLGA1151 socket. Update the board's firmware before swapping.

What no table says

How much of its speed a processor keeps after the first minute depends on the cooling and the power limit of the machine it is in. If you own one of these, measure it: the test is free and runs in this browser.

Free CPU stress test

Questions

Is the Core i5-6600 better than the Core i5-6600K?: By need, on the specifications: a quiet or compact build: the Core i5-6600; upgrading without a new motherboard: either. No specification says how much speed either one keeps under a long load; that depends on the cooling and the power limit of the machine it is in, and it is what a sustained test measures.
Do the Core i5-6600 and the Core i5-6600K use the same socket?: Yes, both use FCLGA1151, so either fits the other's motherboard. Check the board's support list and update its firmware first.
Does the Core i5-6600 or the Core i5-6600K have integrated graphics?: Both do: Intel HD Graphics 530 on the Core i5-6600 and Intel HD Graphics 530 on the Core i5-6600K.
Which runs hotter, the Core i5-6600 or the Core i5-6600K?: The Core i5-6600K is rated at 91 W against 65 W, so it produces more heat under load and needs the larger cooler. How hot either one actually runs depends on the cooler and the case more than on the chip.

More comparisons

Every figure on this table is a design target. None of it is a measurement.

Nothing above describes how a processor behaves twenty minutes into a sustained workload, which is where two chips with nearly identical specifications routinely diverge. A boost clock is a ceiling the vendor permits, not a rate the chip sustains, and whether it holds depends on the cooling, the case, the power profile and the room. None of those appear on a specification sheet.

We deliberately do not reduce these figures to a single score. A composite invented from specifications would look authoritative and measure nothing, and choosing the weights would be choosing the winner.

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