Athlon II X4 651K vs Xeon E5645

Primary details

Comparing Xeon E5645 and Athlon II X4 651K processor market type (desktop or notebook), architecture, sales start time and price.

Place in performance ranking	1578	not rated
Place by popularity	not in top-100	not in top-100
Cost-effectiveness evaluation	1.52	no data
Market segment	Server	Desktop processor
Architecture codename	Westmere-EP (2010−2011)	Llano (2011−2012)
Release date	16 March 2010 (14 years ago)	14 November 2011 (12 years ago)
Launch price (MSRP)	$294	no data

Cost-effectiveness evaluation

Performance per price, higher is better.

Detailed specifications

Xeon E5645 and Athlon II X4 651K 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	6 (Hexa-Core)	4 (Quad-Core)
Threads	12	4
Base clock speed	2.4 GHz	3 GHz
Boost clock speed	2.67 GHz	3 GHz
L1 cache	64 KB (per core)	128 KB (per core)
L2 cache	256 KB (per core)	1 MB (per core)
L3 cache	12 MB (shared)	0 KB
Chip lithography	32 nm	32 nm
Die size	239 mm2	228 mm2
Maximum core temperature	76 °C	no data
Number of transistors	1,170 million	1,178 million
64 bit support	+	+
Windows 11 compatibility	-	-

Compatibility

Information on Xeon E5645 and Athlon II X4 651K 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	2	1
Socket	FCLGA1366,LGA1366	FM1
Power consumption (TDP)	80 Watt	100 Watt

Technologies and extensions

Technological solutions and additional instructions supported by Xeon E5645 and Athlon II X4 651K. You'll probably need this information if you require some particular technology.

Instruction set extensions	Intel® SSE4.2	no data
AES-NI	+	-
Enhanced SpeedStep (EIST)	+	no data
Turbo Boost Technology	1.0	no data
Hyper-Threading Technology	+	no data
Idle States	+	no data
Demand Based Switching	+	no data
PAE	40 Bit	no data
Status	Discontinued	no data

Security technologies

Xeon E5645 and Athlon II X4 651K technologies aimed at improving security, for example, by protecting against hacks.

TXT	+	no data
EDB	+	no data

Virtualization technologies

Virtual machine speed-up technologies supported by Xeon E5645 and Athlon II X4 651K are enumerated here.

AMD-V	-	+
VT-d	+	no data
VT-x	+	no data
EPT	+	no data

Memory specs

Types, maximum amount and channel quantity of RAM supported by Xeon E5645 and Athlon II X4 651K. Depending on the motherboard, higher memory frequencies may be supported.

Supported memory types	DDR3	DDR3
Maximum memory size	288 GB	no data
Max memory channels	3	no data
Maximum memory bandwidth	32 GB/s	no data
ECC memory support	+	-

Peripherals

Specifications and connection of peripherals supported by Xeon E5645 and Athlon II X4 651K.

PCIe version

2.0

no data

Pros & cons summary

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Recency	16 March 2010	14 November 2011
Physical cores	6	4
Threads	12	4
Power consumption (TDP)	80 Watt	100 Watt

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Should you still have questions on choice between Xeon E5645 and Athlon II X4 651K, ask them in Comments section, and we shall answer.

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