In the past, performance gains on the microprocessor front were made by increasing processor speed every few months and marginally improving the existing architecture. A quick look at how the microprocessor industry has evolved over the past two decades showed that a processor generation can last around four/five years.
Over time, Moore’s Law, which states that the number of transistors on a microprocessor doubles every two years, guided the microprocessor industry and set the standard for performance. Apart from transistor density, another variable used to improve performance is the ‘speed’ or frequency of the processors, commonly measured in Megahertz.
Common belief holds that the higher the speed, the ‘faster’ the computer. What has come to be known as the Megahertz Myth has become harder to dispel.
Back in 2004, the two major x86 CPU manufacturers, AMD and Intel, soon found themselves confronted by the following problems: diminishing performance per additional Megahertz, diminishing growth in clock frequency and higher costs and increasing difficulties involved in cramming more transistors per unit area.
Instead of continuing with the traditional way microprocessors were manufactured, both AMD and Intel chose to add a second “core” to their microprocessors, effectively making dual-core processors. The first x86 Dual Core chips debuted in April 2005; introduced first by Intel and a few days later by AMD.
Together with the introduction of the Dual Core architecture, both vendors chose to remove the emphasis on brute speed and focus on the amount of ‘work’ done per cycle. As a result, CPU frequencies have stalled and remained in the region of 3GHz, a speed that was reached back in April 2003, over three years ago.
Having two cores does not halve the time taken to perform a particular task. In real life conditions, dual core processors will actually increase performance by more than 70 per cent. Software developers will have to develop new ways of exploiting so much power while price/performance ratio hits new heights.
There are at least three reasons why adding another core does not improve performance by 100 per cent. It highlights the fact that hardware and software surrounding multicore technology were designed originally for single core microprocessors.
Where Dual Core processors excel is in juggling with several applications simultaneously. This is essential, especially when running power hungry programs like web servers, mathematical or financial packages. A “heavy” application can easily suck away substantial resources from a single core, leaving almost nothing for others running concurrently.
For professional workstation users and corporate, Multi Core is a Godsend gift. Independent benchmarks have shown that one dual core processor offers better performance than two separate single core processors, independent of the manufacturer.
So with all the arithmetic capabilities surrounding it, how does Dual Core actually perform in the real world? Well, more and more applications will take advantage of Dual Core and eventually Quad core on the desktop.
But it is on the server front that things are more exciting. Most server operating systems are already Multi Core ready. Microsoft has already committed massive resources to the technology and Linux and Mac OS, due to their Unix heritage, are already Multi Core friendly.
For the system administrator, Multi Core processing opens a whole new world of upgradeability. A system administrator can start with a dual processor motherboard and one single core processor, then move on to a dual core single processor, then to a quad core single processor and finally add another quad core processor.
All this can be done without changing anything to the original configuration of the server. By leaving the original building blocks intact, microprocessor manufacturers have slashed the TCO (Total Cost of Ownership) of servers overnight.
What is even more impressive is that prices of dual core parts are not as high as one could expect. A quick look at one of UK’s top server seller shows that the difference in price between a single processor server and a dual core processor is a mere £40.
In effect, you are getting a second processor for less than half the retail price of a single core processor. That puts the price of a Dual Core entry level server under £300. The savings can be even more substantial when you move from one socket to two sockets and then to four sockets.
By plugging the right processor at the right time, an average size company can save thousands of pounds in upgrade costs, reduce downtime costs, save time and money and reduce hardware obsolescence.
Intel’s new Xeon Server Chip, codenamed Woodcrest, has already been launched and is slowly trickling down to the market. This chip, based on the award winning Conroe architecture, is much faster, much cooler and therefore consumes less energy than its predecessors. But it is not more expensive than before.
It started as a Dual Core processor and already, the Quad Core version codenamed Clovertown has been launched in November and will be drop in replacement. AMD recently tweaked its Opteron Processor Server series and has already announced Quad core Opterons for the mid-2007.
However, unlike Intel, there has not been any major architectural change during the past few years and AMD has been fairly silent regarding its next Server Chip, codenamed K8L, which would make our performance predictions hazy at best.
Quad Core is the next step. After which, we can expect the number of cores to be doubled with each decrease in manufacturing process to keep the size of processors constant, which happens approximately every two years.
Number of Cores
December 2006 ??
Several other emerging concurrent trends and technologies contribute to make Multi Core more attractive; together with Hardware Virtualisation, 64-bit processing, faster memory and ever smaller manufacturing processes, they are helping microprocessors break away from Moore’s law and deliver even higher performance.
The only dark cloud in the multi core market is the lack of mainstream applications (read Microsoft Office and Internet browsers) that can really take advantage of all that power, on the desktop front at least. When it comes to workstations and servers though, multi core will play a major role in delivering top-notch performance without having to explode IT budgets.
Watch out for Dual Quad-core servers and workstations as they become mainstream in the first half of 2007, making them the most enticing technology to hit the market in a decade. The most impressive is that you can expect these to be available for less than £5000, hardly a massive investment.