Intel Core i5 661 review

A dual-core chip with quad-core rivalling performance and built-in graphics? Intriguing

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Technically, the Intel Core i5 661 is a thoroughly intriguing chip. Exceptionally quick for a dual-core processor, it also packs a graphics core integrated into the processor package itself. If industry analysts are to be believed, this kind of CPU-GPU "fusion" processor is the way of things to come.

Back in 2010, the reality is more mundane. The Core i5 661's 3D rendering abilities are feeble. Admittedly, motherboard-based integrated cores from the likes of AMD or NVIDIA are not much better. But the fact remains this latest integrated graphics core from Intel is effectively worthless for gaming. Fortunately, its 2D video decoding prowess is pretty solid.

Anyway, of more significance is the Core i5 661's performance as a traditional CPU. For a dual-core processor, it's awesome. Thanks to HyperThreading technology, a healthy standard clockspeed of 3.33GHz and the Turbo feature which boost clocks by a further few hundred MHz or so in certain conditions, the 661 beats other dual-core chips with an extremely large stick in highly-threaded software such as video encoding. It even gives quad-core chips such as AMD Athlon II X4 620 a scare.

That sounds impressive until you realise the Core i5 661 is more expensive than any quad-core processor from AMD and even some Intel quad-core chips. The Core i5 750 and 760 are both cheaper and faster. Then there's the AMD Phenom II X6 1055T. Despite being cheaper, it packs six cores and absolutely annihilates the i5 661 in heavily threaded apps.

In other words, the addition of an integrated GPU isn't nearly enough to justify the Core i5 661's premium pricing. That's especially true when you note that supporting motherboards are no cheaper. In fact, if you really wanted to pair a six-core AMD processor with an integrated motherboard, you could. And it would still work out cheaper than the 661 and its fancy fusion graphics.

We like:

Intel's Nehalem CPU architecture makes for an uncommonly quick dual-core CPU. For most PC users, most of the time, it's all the CPU they'll ever need. It's also power efficient, cool running and offers a glimpse of the future courtesy of its CPU-GPU fusion architecture.

We dislike:

In a word, price. The Core i5 661 is at least £50 over priced. Yes, it has a graphics core integrated into the CPU package. But it's a decidedly feeble graphics core of little value to gamers. Moreover, AMD offers a six-core processor for the same price. 'Nuff said.


Fusion may be the future. But for now, this CPU-GPU chip costs too much and delivers too little.

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Tech Specs

Product TypeProcessor
Processor CoreDual-core (2 Core)
Thermal Design Power87 W
Processor ManufacturerIntel
Product FamilyCore i5 i5-600
L3 Cache4 MB
Clock Speed3.33 GHz
Processor SocketSocket H LGA-1156
Brand NameIntel
Green CompliantYes
Green Compliance Certificate/AuthorityRoHS
64-bit ProcessingYes
Thermal Specification69.8°C
L2 Cache512 KB
Product Seriesi5-600
ManufacturerIntel Corporation
Product Modeli5-661
Product NameCore i5 Dual-core i5-661 3.33GHz Processor
Package TypeRetail
Product LineCore i5
Input Voltage1.4 V DC
Manufacturer Part NumberBX80616I5661
Manufacturer Website Address
Marketing Information

With intelligent performance that accelerates in response to demanding tasks, such as playing games and editing photos, the Intel Core i5 processor moves faster when you do. The Intel Core i5 processor automatically allocates processing power where it's needed most. Whether you're creating HD video, composing digital music, editing photos, or playing the coolest PC games with the Intel Core i5 processor you can multitask with ease and be more productive than ever.

Packaged Quantity1
Process Technology32 nm
Limited Warranty3 Year