markstock

6 ms·

31.
by markstock 1y ago
Just a few volumes from my bookshelf related to this: Network Analysis in Geography, Haggett and Chorley Cities and Complexity, Batty Urban Grids, Busquets et al
32.
by markstock 1y ago
Let's be a little more clear: these are not "laws" as much as they are scaling relationships, this is not "new math" (see Ziph and others), and central planning has always had an impact on city development. Neverthe
33.
by markstock 1y ago
Something doesn't add up here. The listed peak fp64 performance assumes one fp64 operation per clock per thread , yet there's very little description of how each PE performs 8 flops per cycle, only "threads are paired up suc
34.
by markstock 1y ago
Exactly this. Whenever I talk about how I got started in computer art over 40 years ago, I always mention the fact that a screen back then was a one-way device: TV network to you. Basic home computers HAD to plug into the TV, and to a kid,
35.
by markstock 1y ago
Yes, this appears to use Stam's Stable Fluids algorithm. Look for the phrases "semi-Lagrangian advection" and "pressure correction" to see the important functions. The 3d version seems to use trilinear interpolation
36.
by markstock 1y ago
Um, no? This is a fine collection of links - much to learn! - but the connection between flow and gravitation is (in my understanding) limited to both being Green's function solutions of a Poisson problem. https://en.wikiped
37.
by markstock 1y ago
It is a fudge if you really are trying to simulate true point masses. Mathematically, it's solving for the force between fuzzy blobs of mass.
38.
by markstock 1y ago
Supercomputers will simulate trillions of masses. The HACC code, commonly used to verify the performance of these machines, uses a uniform grid (interpolation and a 3D FFT) and local corrections to compute the motion of ~8 trillion bodies.
39.
by markstock 1y ago
Yes, the author uses a globally-adaptive time stepper, which is only efficient for very small N. There are adaptive time step methods that are local, and those are used for large systems. If you see bodies flung out after close passes, thre
40.
by markstock 2y ago
I can't recommend cards, but you are absolutely correct about porting CUDA to HIP: there was (is?) a hipify program in rocm that does most of the work.
41.
by markstock 2y ago
The US Treasury has one, though. Not sure if that satisfies the above criteria.
42.
by markstock 2y ago
Here's one that starts with the concept of a straight line and builds all the way to string theory. It's a monumental book, and it still challenges me. Roger Penrose's The Road To Reality.
43.
by markstock 2y ago
If you love this aesthetic and the concepts beneath it, I highly recommend Paolo Soleri's Arcology: The City in the Image of Man.
44.
by markstock 2y ago
I wasn't familiar with the "Wave32" term, but took "RDNA" to mean the smaller wavefront size. I've used both, and wave32 is still quite effective for CFD.
45.
by markstock 2y ago
Maybe never by the big players, but RDNA and even fp32 are perfectly fine for a number of CFD algorithms and uses; Stable Fluids-like algorithms and Lagrangian Vortex Particle Methods to name two.
46.
by markstock 2y ago
This has not been my experience in the academic/research side. Poison solver-based incompressible CFD regularly runs ~10x faster on equivalently-priced GPU systems, and has been doing so since I've been following it (since 2008).
47.
by markstock 2y ago
I'm surprised no one has mentioned Vc. I found ispc clunky and not as performant, and std::simd didn't support some useful math ops like rsqrt. Vc has been around for years, I have no trouble including it in my codes, it has maski
48.
by markstock 2y ago
The Earth is a multi-physics complex system and OP claiming to "Simulate the Earth" is misleading. Methods that work on the atmosphere may not work on other parts. There are numerous scientific projects working on simulation earth
49.
by markstock 2y ago
Each node has 4 GPUs, and each of those has a dedicated network interface card capable of 200 Gbps each way. Data can move right from one GPU's memory to another. But it's not just bandwidth that allows the machine to run so well,
50.
by markstock 2y ago
FYI: LUMI uses a nearly identical architecture as Frontier (AMD CPUs and GPUs), and was also made by HPE.
51.
by markstock 2y ago
https://docs.olcf.ornl.gov/systems/frontier_user_guide.html This will have much of what you need.