According to the latest indications from Intel, its new processor, code named Larrabee, will feature between 8 and 48 x86 cores and will be slated for both general purpose and graphics processing (source: Computer World). Compare this to Nvidia’s Tesla 10P with its 240 cores and AMD’s soon to be released Firestream 9250, which will sport a whopping 500 cores. So obviously, when it comes to number crunching, Intel’s offering does not even come close. Worse, it won’t be released until 2009 at the earliest. Intel counters that Larrabee will be compatible with existing programming languages such as C and C++ and thus take advantage of the wide familiarity that programmers already have with these languages. Well, wup dee do! That'll teach them.
Update (8/5): Please read the comments below. A reader wrote to point out that AMD and Nvidia misadvertise the number of cores built into their graphics processors.
Hideous to the Core
Larry Seiler, chief architect in Intel's visual computing group, claims that Larrabee “will combine the full programmability of the CPU with the kinds of parallelism and other special capabilities of graphics processors” (source: SlashGear). This can only mean one thing. A programmer will have the option of using a percentage of the cores for general purpose, coarse-grained, MIMD multithreaded parallelism while dedicating the rest for fine-grained, SIMD vector processing for graphics purposes. How the partitioning will be realized or whether it will be fixed or programmable is anyone’s guess. It remains that Larrabee is hideous to the core, if you pardon the pun. Heterogeneous processors will wreak havoc on productivity due to the increased programming difficulty of having to deal with two incompatible modes of execution. In addition, effective load balancing across all the cores becomes a nightmare to manage, if it is at all possible.
Intel’s Folly and Industry Lemmings
The following is a quote from an EETimes article:
Intel says it has a number of internal teams, projects and software-related efforts underway to speed the transition, but the tera-scale research program has been the single largest investment in Intels technology research and has partnered with more than 400 universities, DARPA and companies such as Microsoft and HP to move the industry in this direction.This is too horrible to even contemplate. In my considered opinion, Intel is single-handedly driving the computer industry over a cliff and the rest of the industry is cheerfully following along like a bunch of lemmings. Oh, the humanity!
Intel Needs to Go to Rehab
Intel is high on its own dope. Over the past several months, from the time I posted my Nightmare on Core Street series of articles, Intel Research has visited my blog hundreds of time. My message is simple: the industry must get rid of its addiction to multithreading and algorithmic computing and adopt a universal, non-algorithmic parallel programming model, one which can handle general purpose computing and graphics processing with equal ease, or anything else you can throw at it. The heterogeneous or hybrid approach to parallelism is absurd to the extreme. It hurts me just to think about it. Justin Rattner needs to go to computer science rehab and take all his buddies with him, in my opinion. Which reminds me of Amy Winehouse's Rehab song:
I’m sorry but the only thing that is keeping me from tearing my hair out is a little bit of humor. Besides, I like Amy Winehouse, drugs, alcohol and all. :-D
How to Solve the Parallel Programming Crisis
Heralding the Impending Death of the CPU
Parallel Computing: Both CPU and GPU Are Doomed
CNET has a nice article on Larrabee that explains certain details about the chip's vector and scalar units. The author is not very impressed (he compares it to a science project that got out of hand) but check it out anyway.