Intel Larrabee – Moving Into High-End Discrete GPUs

Larrabee details

Larrabee is based on an x86 CPU, which is what powers your Windows and Mac based PCs. In fact, its roots go all the way back to the Intel Pentium processor, albeit with tweaks and enhancements from todays technology. Youre going to see CPU in a lot of the information were presenting here today because the other side of Larrabee is the flexibility of what it can do, it is capable of processing and accelerating normal workloads that your CPU currently does, as well as providing the potential to take gaming performance to a new level. Intel initially plans to market Larrabee to discrete graphics applications such as gaming, will support DirectX and OpenGL. This means it will run existing games and programs. They also expect many large scientific and engineering projects to benefit from the Larrabee native C/C++ programming model.

There is so much data that Intel is giving about their new many-core Larrabee, but lets focus on what is important without getting into doctorate level details. Here is some info directly from Intels press fact sheet.

• The Larrabee architecture has a pipeline derived from the dual-issue Intel Pentium processor, which uses a short execution pipeline with a fully coherent cache structure. The Larrabee architecture provides significant modern enhancements such as a wide vector processing unit (VPU), multi-threading, 64-bit extensions and sophisticated pre-fetching. This will enable a massive increase in available computational power combined with the familiarity and ease of programming of the Intel architecture.
• Larrabee also includes a select few fixed function logic blocks to support graphics and other applications. These units are carefully chosen to balance strong performance per watt, yet contribute to the flexibility and programmability of the architecture.
• A coherent on-die 2nd level cache allows efficient inter-processor communication and high-bandwidth local data to be access by CPU cores, making the writing of software programs simpler.
• The Larrabee native programming model supports a variety of highly parallel applications, including those that use irregular data structures. This enables development of graphics APIs, rapid innovation of new graphics algorithms, and true general purpose computation on the graphics processor with established PC software development tools.
• Larrabee features task scheduling which is performed entirely with software, rather than in fixed function logic. Therefore rendering pipelines and other complex software systems can adjust their resource scheduling based each workloads unique computing demand.
• The Larrabee architecture supports four execution threads per core with separate register sets per thread. This allows the use of a simple efficient in-order pipeline, but retains many of the latency-hiding benefits of more complex out-of-order pipelines when running highly parallel applications.
• The Larrabee architecture uses a 1024 bits-wide, bi-directional ring network (i.e., 512 bits in each direction) to allow agents to communicate with each other in low latency manner resulting in super fast communication between cores.
• The Larrabee architecture fully supports IEEE standards for single and double precision floating-point arithmetic. Support for these standards is a pre-requisite for many types of tasks including financial applications.

So on paper Larrabee looks like a great combination of CPU and GPU and I have to admit it looks promising. With the power that Larrabee brings Intel is pushing hard towards future games being real-time Ray-Traced and moving away from whats been used for the last 10 years, rasterization. Again, going into detail for either design philosophy goes beyond the scope of this article. Both have their pros and cons but Ray-Tracing is what Intel sees as the future. One thing to keep in mind is that we arent going to see a sudden change overnight, nor in the immediate future. Ray-Traced gaming is still years away, some outside of Intel say 4-6 years. The important thing to remember is that hardware drives software, so with the hardware in place current and future developers have the option of which path they want to choose.

Legit Bottom Line: Intel lets Larrabee details out of the bag. On paper it looks grand and poised to take the future of computing and gaming by brute force with an army of CPUs. Unfortunately we likely wont get our first look at this prospect until late 2009 or early 2010.