Pentium D 840 vs Core 2 Quad Q8400

Primary details

Comparing Core 2 Quad Q8400 and Pentium D 840 processor market type (desktop or notebook), architecture, sales start time and price.

Place in the ranking	2266	not rated
Place by popularity	not in top-100	not in top-100
Market segment	Desktop processor	Desktop processor
Power efficiency	1.30	no data
Architecture codename	Yorkfield (2007−2009)	Smithfield (2005)
Release date	19 April 2009 (15 years ago)	May 2005 (19 years ago)

Detailed specifications

Core 2 Quad Q8400 and Pentium D 840 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	2
Base clock speed	2.66 GHz	3.2 GHz
Boost clock speed	0.67 GHz	3.2 GHz
Bus rate	1333 MHz	no data
L1 cache	64 KB (per core)	28 KB
L2 cache	4 MB (shared)	2 MB
L3 cache	0 KB	0 KB
Chip lithography	45 nm	90 nm
Die size	2x 82 mm2	206 mm2
Maximum core temperature	no data	70 °C
Maximum case temperature (TCase)	71 °C	no data
Number of transistors	456 million	169 million
64 bit support	+	+
Windows 11 compatibility	-	-
VID voltage range	0.85V-1.3625V	1.2V-1.4V

Compatibility

Information on Core 2 Quad Q8400 and Pentium D 840 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	2
Socket	FCLGA775,LGA775	PLGA775
Power consumption (TDP)	95 Watt	130 Watt

Technologies and extensions

Technological solutions and additional instructions supported by Core 2 Quad Q8400 and Pentium D 840. You'll probably need this information if you require some particular technology.

Enhanced SpeedStep (EIST)	+	+
Turbo Boost Technology	-	-
Hyper-Threading Technology	-	-
Idle States	+	+
Thermal Monitoring	+	-
Demand Based Switching	-	-
PAE	no data	32 Bit
FSB parity	-	-

Security technologies

Core 2 Quad Q8400 and Pentium D 840 technologies aimed at improving security, for example, by protecting against hacks.

TXT	-	-
EDB	+	+

Virtualization technologies

Virtual machine speed-up technologies supported by Core 2 Quad Q8400 and Pentium D 840 are enumerated here.

VT-d	no data	-
VT-x	+	-

Memory specs

Types, maximum amount and channel quantity of RAM supported by Core 2 Quad Q8400 and Pentium D 840. Depending on the motherboard, higher memory frequencies may be supported.

Supported memory types

DDR1, DDR2, DDR3

DDR1, DDR2, DDR3

Graphics specifications

General parameters of integrated GPUs, if any.

Integrated graphics card

On certain motherboards (Chipset feature)

no data

Peripherals

Specifications and connection of peripherals supported by Core 2 Quad Q8400 and Pentium D 840.

PCIe version

2.0

no data

Pros & cons summary

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Physical cores	4	2
Threads	4	2
Chip lithography	45 nm	90 nm
Power consumption (TDP)	95 Watt	130 Watt

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