With 8 Cards, Wolfenstein Ray Traced 7.7x Faster 97
An anonymous reader writes "As Slashdot readers know Intel's research project on ray tracing for games has recently been shown at 1080p, using eight Knights Ferry cards with Intel's 'Many Integrated Core' architecture. Now a white paper goes into more detail, documenting near-linear scaling for the cloud setup with 8 cards, and gives details on the implementation of 'smart anti-aliasing.' It will be interesting to see how many instances of Intel's next MIC iteration — dubbed Knights Corner, with 50+ cores — will be required for the same workload."
Re:Nice scaling (Score:4, Interesting)
It's also much more demanding on hardware. One of the big drawbacks is it requires a lot of scattered reads out of memory making caching much less effective. You need tons of bandwidth to low latency memory to make it happen. We're still a very long ways out from having this possible in reasonably-priced consumer GPUs.
Yes, it is exactly what Intel Mic card are awesome for. They are generic x86 core with 4-way SMT and a buttload of memory bandwidth. I worked with Knight Ferry prototypes and studied the scalability of the worst case of algorithms for scattered memory access: graph algorithms. (The paper will be published soon but the preprint is available at http://bmi.osu.edu/hpc/papers/Saule12-MTAAP.pdf [osu.edu] .) Basically, we achieve close to optimal scalability on most of our tests.
These MIC card are designed to scale in good cases (compact memory and SIMDizable operations such as dense matrix vector multiplication, or image processing) but almost in the bad cases (lots of indirections, accessing caches lines in pathological scenarios such as sparse matrix vector multiplication, graph algorithms.)
I am excited to get a hold on the commercial card (we worked on prototypes) to make a CPU/GPU/MIC comparison.