Have been watching advances in computing power for some time, since university really. I did research in parallel algorithms and architecture for my first position at the university and later applied practically on Wall Street. In those days super-expensive machines like the Intel Hypercube, Paragon, and many other architectures were the backbone of the HPC community.
HPC (High Performance Computing) roughly breaks down into 4 categories:
- Big iron supercomputers (MIMD generally)
- Distributed computing (these days advertised as Cloud Computing)
- The emerging SIMD GPU based solutions
- Quantum Computing (not really here yet for the mainstream)
In the machine learning and optimisation world there are massive problems, some of which are not computable on von-neumann architectures, as their runtime would be astronomical. An (absurd) example of such a problem would be to simulate a large number monkeys typing on typewriters, stopping when one produces the works of Shakespeare. The number of monkeys required to produce such a work on average in astronomical. This seems like an absurd problem, but is comparable to the GP / GA approach.
Then of course there are numerous problems with high dimensionality and/or with polynomial order complexity.
Supercomputing on the Cheap
The FASTRA team at the University of Antwerp has put together an inexpensive multi-teraflop machine with 7 gaming cards. Check out their video.
Unfortunately the “easy” part of these sort of solutions is the hardware. The problem is the (often) great expense to develop one’s models in a SIMD framework, so can be applied to for the GPU architecture. Although there is now standardization on the low-level C-variant used to program GPUs, there are significant differences between different models of GPUs, that even if you manage to write a correct SIMD program, may have to rearrange for a specific GPU implementation. (I guess this is not all that different from my experiences with big-iron parallel architectures of the past).
One could have a team devoted to parallelization, tuning, and retuning / reworking for the new GPUs that are out periodically. Very time consuming!
For my work, the problems that would map well are particle filters and monte-carlo based models, each of which have obvious fine-grained parallel operations.
Quantum Computing
The other notable announcement this week was Google’s use of quantum computing to solve pattern recognition problems. I have not done the leg-work to fully understand the algorithms in quantum computing, but broadly it seems to be a matter of framing one’s problems statistically as path integration problems (i.e., expectations), where quantum computing allows the paths to be explored simultaneously.