In a webcast, Dr Mark Seager of Lawrence Livermore National Laboratory, highlighted the reasons multi-core is now becoming so popular. According to Mr Seager, Moore’s Law has been misused over the past decade, as it actually refers to the doubling of the transistor packing density on a substrate at a constant cost every 24 months.
This has been corrupted by popular misconception to refer to doubling of processor speed every 24 months. Mr Seager states that we have reached the processor speed limit because the power density in watts/cm2 has now reached a level that cannot be supported.
In the late 1980s, bipolar transistors formed the core of all computer systems, but this technology also suffered from power density problems, and by the 1990s was threatening to limit transistor density and, therefore, processor speed. However, complementary metal-oxide semiconductor (CMOS) technology provided a solution enabling Moore’s Law to continue, and the processor speed to also follow the same rule, hence the misconception.
Nevertheless, with CMOS now reaching its power density limits, what options do processor manufacturers have? With no new technology immediately available similar to CMOS in the 1990s, (nanotechnology is being researched, but experts do not expect any commercial products for at least a decade) the industry has chosen to replicate, and hence produce multi-core processors.
The issue for the industry is how to use these multi-cores; for example, the Playstation 3 has one PowerPC core and eight synergistic processor units (SPUs), which allow the gaming console to display advanced graphics and mimic real-life scenarios. Meanwhile, the Xbox 360 has a three-core unit consisting of general purpose processing units (GPUs) to do the same thing. Dreamworks – the animation film producer – uses multi-core technology to render frames in its films, according to Jim Mainard, head of R&D at Dreamworks Animation. This process lends itself to massive parallelization, which is suited to multi-core technology.
However, beyond the gaming and media industry, producing software that can work effectively with multi-core processors is not prevalent, and, in fact ,requires people to think differently about the way they approach their work.
To answer the question of whether multi-core will make applications run faster, the answer is probably. Because applications do not just rely on processor speed alone, but also have memory and I/O requirements, it all depends on the individual application and what its specific requirements are.
However, multi-core processors are here to stay, and while it may take some time for the software industry to catch up with the processor manufacturers, the gaming industry looks set lead the way. One final thought on the subject that has yet to receive a common response is how will the vendors license products in a multi-core world, and how will they ensure compliance?
Source: OpinionWire by Butler Group (www.butlergroup.com)
