AnsweredAssumed Answered

How GCN scheduling work??

Question asked by arvin99 on Jan 20, 2014
Latest reply on Jan 21, 2014 by arvin99

Hi, I am confused about how GCN scheduling work.

Let's say, if I define work group size is 32  and global work items is 262144 in OpenCL, then in four cycle clock there will be 32 PE (Processing Element)

( 16 PE in first clock cycle and 16 PE in second clock cycle) that worked and the other PE is idle for single wavefront right??

The total wavefront that worked will be 8192  wavefronts.

How about GCN ?? If I define work group size less than 64, are there idle PE or it is dynamically work for the next wavefront??

Can someone explain to me by using these two images ??


a) Taken from AnandTech Portal | AMD's Graphics Core Next Preview: AMD's New GPU, Architected For Compute

    Wavefront Execution Example: SIMD vs. VLIW. Not To Scale - Wavefront Size 16

http://images.anandtech.com/doci/4455/Wavefront.png


b) Taken from AMD: Southern Islands (7*** series) Speculation/ Rumour Thread - Page 33 - Beyond3D Forum

    Copyright to Hiroshige Goto

Outcomes