Intel Core 2 Duo E8400 vs Intel Core i7-2600K

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Core 2 Duo E8400 compared with Core i7-2600K

	IntelCore 2 Duo E8400	IntelCore i7-2600K
Overview
Released
Released	January 2008	January 2011
Cores and clocks
Cores
Cores	2	4 (better)
Threads
Threads	2	8 (better)
Base clock
Base clock	3 GHz	3.4 GHz
Boost clock
Boost clock	–	3.8 GHz
L3 cache
L3 cache	–	8 MB
Cores
Cores	Wolfdale; two cores and two threads, without Hyper-Threading. Intel’s archived exact E8400 specifications are attached to the maker datasheet distributed by Mouser.	Four cores with Hyper-Threading; Intel Turbo Boost 2.0. Expert Reviews and TechRadar confirm the unlocked CPU multiplier.
Clocks
Clocks	Published operating frequency 3.00 GHz; 1333 MHz front-side bus. Intel explicitly lists no Turbo Boost, so no boost figure is supplied. Intel’s CES fact sheet specifies January 2008 availability for this exact model; TechSpot’s 1 February review confirms retail stock, with early shortages and prices above target. An exact first-sale day remains unverified.	Maximum turbo is a single-core frequency; sustained clocks depend on cooling. Intel's 5 January launch notice gives 9 January availability for quad-core systems.
Cache
Cache	6 MB shared L2 cache; no L3 figure supplied.	–
Graphics and AI
Built-in graphics
Built-in graphics	No	Yes
Graphics
Graphics	No integrated graphics, explicitly confirmed by the exact BX80570E8400 Newegg listing; motherboard graphics are separate.	Intel HD Graphics 3000; 850 MHz base, up to 1.35 GHz; two displays; Quick Sync Video.
Platform
Socket
Socket	LGA775	LGA1155
Base power
Base power	65 W	95 W
Unlocked
Unlocked	–	Yes
Cooler in the box
Cooler in the box	Yes	–
Memory support
Memory support	Memory and I/O transactions pass through the front-side bus and chipset, as Intel’s datasheet states; supported memory types and capacity depend on the motherboard.	Up to 32 GB; two channels; DDR3-1066/1333; 21 GB/s maximum bandwidth as Intel publishes; ECC not supported.
PCIe
PCIe	–	PCIe 2.0; 16 CPU lanes.
Process
Process	45 nm; Wolfdale; LGA775; SSE4.1 support.	32 nm; Sandy Bridge; 37.5 × 37.5 mm package; 72.6°C maximum case temperature, not junction temperature.
Cooler
Cooler	Intel’s boxed-processor specification confirms a supplied cooling solution; exact BX80570E8400 listing confirms heatsink and fan. Published processor TDP is 65 W.	LGA1155 is incompatible with LGA1156. TechRadar describes the launch P67 chipset as supporting CPU overclocking and H67 as supporting the integrated graphics output; chipset choice affects available features. Intel publishes no separate maximum turbo-power figure.