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Know which chip best processes your PC

June 21, 2010 12:02 IST

Do terms like Pentium, Celeron, Dual core, icore, Atom, Opteron or Phenom matter fox you when buying computers? You may want to do with some help.

If you go to buy a desktop or laptop, you may notice that the configurations of the machines, showcased on labels in showrooms, have words like Celeron, Atom, Core2duo, i3, i5, i7, Athlon or Phenom. Ask the salesperson, and you may have a tough time filtering the hardsell to arrive at a meaningful decision, if you are uninitiated.

This need not be the case if you know your primary reason for buying a computer (desktop or laptop). The rest will follow with some homework. For those who do not have the time to do so, here's a primer. It's in no way exhaustive and will have to be supplemented by reading PC review websites and PC magazines.

To begin with, alpabhets and words such as Core i3 or Athlon stand for microprocessors that power your machines. In other words, without a microprocessor from an Intel or AMD, your computer simply won't boot, or start. A microprocessor can be likened with your heart or brain.

Also known as a central processing unit (CPU), it's a computer's engine, fabricated on a single silicon chip, which rests on a motherboard along with the random access memory (RAM) card and other important peripherals.

A microprocessor executes commands and runs computer programs. Typical computer programs that must be processed by CPUs include internet browsers, word processors, and image-editing software. Hence, whether you are purchasing a PC, a video game console or any other electronic device, the performance of its microprocessor is a primary consideration.

Specifications include clock frequency, addressable memory and the number of cores (for instance, dual core, quad core or multi-core - the more the core, the better). In sum, the faster the processor, the racier your machine.

The clock rate is often called clock frequency or CPU frequency. It is most often measured in gigahertz (GHz) and megahertz (MHz) and is directly proportional to the performance of the microprocessor. For instance, if a microprocessor has a clock rate of 3 GHz, it can perform around 3 billion math calculations a second. With a clock rate of 100 MHz, it can execute about 100 million calculations a second.

The addressable memory that the microprocessor supports is also important. The more the memory, the faster will it upload and download web pages, graphics and videos. Addressable memory is displayed most often in gigabytes (1GB = 1 billion bytes) or megabytes (1MB = 1 million bytes).

Now, words like Core 2 simply represent a brand encompassing a range of Intel's consumer 64-bit x 86-64 single-, dual-, and quad-core microprocessors based on the Core microarchitecture. Core-based processors do not have Hyper-Threading (which makes the computer believe it has two processors instead of a single physical one and allocates tasks more efficiently) technology that was found in Pentium 4 processors.

This is because the Core microarchitecture is a descendant of the P6 microarchitecture, which was used by Pentium Pro, Pentium II, Pentium III, and Pentium M (meant for laptops, just as the Atom processor today).

The successors to the Core 2 brand are a set of Nehalem microarchitecture-based processors called Core i3, i5, and i7. Core i7 was officially launched in November 2008 as a family of three quad-core processor desktop models. More models started appearing through 2009. With the launch of 32 nanometre (nm) processors, Intel plans to discontinue some Atom, Celeron, Pentium, Core 2, and even Core i7 models.

The Core 2 Duo has been the processor of choice in laptops for about three years. The Core i3 is very similar - both are dual-core processors and most Core 2 Duo(s) and Core i3(s) have similar clock speeds. However, the processors are based on different architectures. The Core i3 is the slowest variant of the Nehalem-based processor.

Intel chips are very well known. However, it's important to note that Intel's rival AMD has powerful chips, which have historically been 25-30 per cent cheaper than Intel chips with similar processing powers. This time around, for instance, Intel's core chips are being compared with AMD's Phenom chips.

However, even with recent gains, AMD held only 12.1 per cent of the global microprocessor market, compared with Intel's 80.6 per cent, research firm iSupply Corp said in March 2010.

Going ahead, AMD's recently demonstrated its first Fusion processors - which combine traditional CPUs and graphics cores into what it calls accelerated processing units (APUs).

AMD has been talking about the Fusion strategy for years, ever since it bought graphics chip maker ATI. Its laptop roadmap contains two Fusion chips for next year - Llano, a quad-core chip based on a 32nm process, aimed at mainstream and performance laptops; and Ontario, a lower-power dual-core chip aimed at the ultrathin and netbook markets.

Intel, on its part, is showing off Sandy Bridge, which will be its new architecture at 32nm. Though many specifications are not out, experts expect to see both dual-and quad-core versions as part of its 2011 notebook platform.

Leslie D Monte in Mumbai
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