GTX 560
830gpu/1002mem/1660shaders clock (MHz), 128GB/s Bandwidth,
1950M transistors, 40nm technology
1.66GHz with 336 shaders but double floats are ~8 times slower therefore ~
70 ?
Intel i5 2300 is only 5.7 times slower than GeForce GTX 560 in double floats
(see Parallel M-set test). It is not bad:
1. we get it "for free" and
2. we can't use Intel GPU (GMA) cores power yet but -
"The Ivy Bridge GPU adds support for OpenCL 1.1, DirectX 11 and OpenGL 3.1"
(
AnandTech: Intel's Ivy Bridge Architecture Exposed)
I think Tesla is more than 4 times faster, but what about Knights Corner? :)
| Operation | float write | float copy | float4 copy |
| E-350 | 3.3 | 5.5 | 5.9 |
| GTX 560 | 91.5 | 113.7 |
For GTX 560 the maximum bandwidth is 128GB/s. Global memory is accessed via 32-, 64-, or 128-byte memory transactions. In one float transaction for (32×8) thread blocks a warp reads 32×4 bytes = 128 consecutive bytes with maximum bandwidth. But in 48 core streaming multiprocessor (SM) two schedulers place one warp and a half at the same time. Therefore SM reads at first 128 then 64 bytes and we get ~3/4 of the maximum bandwidth. To get maximum bandwidth 1/2 of warp shall read (write) 128 consecutive bytes as like as in float4 transactions for (16×8) thread blocks.
Note also that: "A cache line is 128 bytes and maps to a 128-byte aligned segment in device memory. Memory accesses that are cached in both L1 and L2 are serviced with 128-byte memory transactions whereas memory accesses that are cached in L2 only are serviced with 32-byte memory transactions."
We have several questions:
[1] Jos Stam
Stable
Fluids
[2] Mark J. Harris
Fast Fluid Dynamics Simulation on the GPU
GPU Gems:
Chapter 38
[3] Keenan Crane, Ignacio Llamas, Sarah Tariq
Real-Time Simulation and Rendering of 3D Fluids.
GPU Gems. Chapter 30