All about multi core processors

BANGALORE, INDIA: Multi-core CPUs are nothing new. They've existed in the RISC world for ages. However, it's a relatively new phenomenon on the x86 platform. Hence that's what we'll elaborate on in this article, along with some other varieties of multi-core. In the world of IT, there's always been a cat and mouse chase between hardware and software. Everytime a fast, new hardware is introduced, software developers come out with applications to quickly consume its power. Likewise, the hardware manufacturers then start working on something to manage the growing demands from the software and the cycle repeats.

For a long time, in CPUs, this demand from applications was largely being addressed by increasing the clock speed, FSB, etc. This went on until the clock speeds hit a ceiling, exceeding which was just not possible. Plus, higher clock speeds also affected the power consumption and heat generation by the CPU. The only way out therefore was to increase the number of CPUs in the system. Adding more physical sockets into a system would have increased circuit complexity and increased the cost. A more efficient solution was required that would manage the costs, be more power efficient, and yet be powerful enough to manage the growing demands from software.

That's how multi-core CPUs came into being, or putting in multiple cores within the same CPU die without increasing its size. Today, the number of cores has increased to four, and next year, expect it to go up to 8 and continue increasing thereafter.

So now, the new battle of increasing the number of cores has started, or shall we call it multi-core wars.

Opportunities Galore for Multi-Core

Multi-core CPUs have not only impacted the traditional desktop PC, laptop, and server markets, but have also opened up a plethora of opportunities for many other segments. So whether it's gadgets like cellphones, smart phones, PDAs, or consumer appliances like microwaves or even the automobiles, everything can benefit from multi-core CPUs, and work is on to achieve the same.

Multi-Core this year

Lots of exciting things happened in multi-core this year. Intel bombarded the market with a slew of new multi-core processors for desktops, laptops, and servers. So much so that before one could even digest the launch of a new CPU, another more enhanced CPU gets released. For instance, it's not been long since the 65 nm processor came into the market, and 45 nm based CPUs have already been announced. Intel also has plans to move to 32 nm process very soon. In Jan this year, it introduced its Quad Core range of CPUs as well.

Likewise, AMD, which had been lagging in the multi-core race, finally came up with their first Quad Core Processor called Barcelona for servers. Plus, they also launched a higher clock speed Dual Core processor, called the AMD Athlon 64 Black Edition. AMD has also announced its 45 nm based processors and has plans to move to 32 nm as well.

We have also seen specially designed motherboards that can accommodate two quad core processors, which is meant for high-end workstations. At this pace, we're likely to see such technologies moving to the desktop as well. Interestingly, vendors are offering new upgraded processors and still continuing support for the previous generations so as to provide enough options for the consumer to choose from.

Multi-Core in graphics and gaming

We also witnessed an increased demand of gaming consoles like the XBox 360, Playstation, and Wii. All of them use multi core processors. This is one segment where the demand for more computing power will surely increase apart from the regular gaming potential.

GPUs too have matured with Windows Vista's launch. This year we have seen GPUs having as many as 320 stream processing units (cores). Both NVIDIA and ATI have dished out GPUs that not only play the latest games, but are also capable of handling parallel processing tasks in an effective and efficient manner. In fact, there's even talk of actually replacing CPUs with GPUs.

What to expect in the future

One of the key drivers behind multi-core CPU technologies is virtualization. Both Intel and AMD have independently developed their own virtualization extensions. Intel has plans of adding the technology 'Virtualization for Directed I/O (VT-d)' that will provide a way for configuring interrupt delivery to individual virtual machine and an Input Output Memory Management Unit (IOMMU) for preventing a virtual machine from using DMA to break isolation. AMD too has similar plans. It plans to add specifications for IOMMU that will provide a way for configuring interrupt delivery to individual virtual machines. AMD has already announced an initiative named Torrenza to promote the usage of Hyper Transport for plug-in cards and coprocessor. This technology is widely used by AMD, Transmeta, NVIDIA, VIA and SiS. Macro Fusion, a term coined by Intel refers to the processor's ability to combine several instructions into one, thus optimizing it and making for a faster execute.

Unified Shader architecture and introduction of Geometry Shader has also added a new dimension to the way games are played and developed. Looking ahead we might soon see Hot-spare processor core as well, the way it's available for storage, power supplies, and memory. AMD has decided to add more processor sockets to their motherboard and an open socket specification. This would eventually allow the addition of specialized processors into the sockets that are free.

From 90nm to current 45nm processors, the journey had been enthralling and beneficiary. Very soon, may be by early 2009, we will have 32nm processors in the market. The future looks interesting as AMD plans to dish out the FUSION, which will be mainly a heterogeneous multi-core processor. Intel has similar plans too; they plan to come out with their first ever GPU (Larrabee), therefore a processor in similar line with AMD's Fusion can't be ruled out.