i5-661 vs i5-2550K

Primary details

Comparing Core i5-2550K and Core i5-661 processor market type (desktop or notebook), architecture, sales start time and price.

Place in the ranking	1733	2124
Place by popularity	not in top-100	not in top-100
Cost-effectiveness evaluation	1.65	0.12
Market segment	Desktop processor	Desktop processor
Power efficiency	2.58	1.69
Architecture codename	Sandy Bridge (2011−2013)	Clarkdale (2010−2011)
Release date	January 2012 (12 years ago)	7 January 2010 (14 years ago)
Launch price (MSRP)	$189	$252

Cost-effectiveness evaluation

Performance per price, higher is better.

i5-2550K has 1275% better value for money than i5-661.

Detailed specifications

Core i5-2550K and Core i5-661 basic parameters such as number of cores, number of threads, base frequency and turbo boost clock, lithography, cache size and multiplier lock state. These parameters indirectly say of CPU speed, though for more precise assessment you have to consider their test results.

Physical cores	4 (Quad-Core)	2 (Dual-core)
Threads	4	4
Base clock speed	3.4 GHz	3.33 GHz
Boost clock speed	3.8 GHz	3.6 GHz
Bus rate	5 GT/s	2.5 GT/s
L1 cache	64 KB (per core)	64 KB (per core)
L2 cache	256 KB (per core)	256 KB (per core)
L3 cache	6144 KB (shared)	4 MB (shared)
Chip lithography	32 nm	32 nm
Die size	216 mm2	81 mm2
Maximum core temperature	73 °C	70 °C
Number of transistors	1160 million	382 million
64 bit support	+	+
Windows 11 compatibility	-	-
Unlocked multiplier	+	-

Compatibility

Information on Core i5-2550K and Core i5-661 compatibility with other computer components: motherboard (look for socket type), power supply unit (look for power consumption) etc. Useful when planning a future computer configuration or upgrading an existing one. Note that power consumption of some processors can well exceed their nominal TDP, even without overclocking. Some can even double their declared thermals given that the motherboard allows to tune the CPU power parameters.

Number of CPUs in a configuration	1	1
Socket	FCLGA1155,LGA1155	FCLGA1156
Power consumption (TDP)	95 Watt	87 Watt

Technologies and extensions

Technological solutions and additional instructions supported by Core i5-2550K and Core i5-661. You'll probably need this information if you require some particular technology.

Instruction set extensions	Intel® SSE4.1, Intel® SSE4.2, Intel® AVX	Intel® SSE4.2
AES-NI	+	+
AVX	+	-
Enhanced SpeedStep (EIST)	+	+
Turbo Boost Technology	2.0	1.0
Hyper-Threading Technology	-	+
Idle States	+	+
Thermal Monitoring	+	-
Flex Memory Access	+	no data
Demand Based Switching	no data	-
PAE	no data	36 Bit
FDI	-	+
Fast Memory Access	+	no data

Security technologies

Core i5-2550K and Core i5-661 technologies aimed at improving security, for example, by protecting against hacks.

TXT	-	+
EDB	+	+
Identity Protection	+	-

Virtualization technologies

Virtual machine speed-up technologies supported by Core i5-2550K and Core i5-661 are enumerated here.

VT-d	-	+
VT-x	+	+
EPT	+	+

Memory specs

Types, maximum amount and channel quantity of RAM supported by Core i5-2550K and Core i5-661. Depending on the motherboard, higher memory frequencies may be supported.

Supported memory types	DDR3	DDR3
Maximum memory size	32 GB	16.38 GB
Max memory channels	2	2
Maximum memory bandwidth	21 GB/s	21 GB/s

Graphics specifications

General parameters of integrated GPUs, if any.

Integrated graphics card	no data	Intel HD Graphics for Previous Generation Intel Processors
Quick Sync Video	+	-
Clear Video HD	-	+

Graphics interfaces

Available interfaces and connections of Core i5-2550K and Core i5-661 integrated GPUs.

Number of displays supported

no data

2

Peripherals

Specifications and connection of peripherals supported by Core i5-2550K and Core i5-661.

PCIe version	2.0	2.0
PCI Express lanes	16	16

Synthetic benchmark performance

Various benchmark results of the processors in comparison. Overall score is measured in points in 0-100 range, higher is better.

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Combined synthetic benchmark score

This is our combined benchmark performance rating. We are regularly improving our combining algorithms, but if you find some perceived inconsistencies, feel free to speak up in comments section, we usually fix problems quickly.

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Pros & cons summary

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Performance score	2.60	1.56
Physical cores	4	2
Power consumption (TDP)	95 Watt	87 Watt

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Should you still have questions on choice between Core i5-2550K and Core i5-661, ask them in Comments section, and we shall answer.

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