{"action":"created","issue":{"url":"https://api.github.com/repos/clMathLibraries/clFFT/issues/67","labels_url":"https://api.github.com/repos/clMathLibraries/clFFT/issues/67/labels{/name}","comments_url":"https://api.github.com/repos/clMathLibraries/clFFT/issues/67/comments","events_url":"https://api.github.com/repos/clMathLibraries/clFFT/issues/67/events","html_url":"https://github.com/clMathLibraries/clFFT/issues/67","id":59132831,"number":67,"title":"clFFT work group size problem on Radeon 4600 GPUs","user":{"login":"PhilSee","id":11217251,"avatar_url":"https://avatars.githubusercontent.com/u/11217251?v=3","gravatar_id":"","url":"https://api.github.com/users/PhilSee","html_url":"https://github.com/PhilSee","followers_url":"https://api.github.com/users/PhilSee/followers","following_url":"https://api.github.com/users/PhilSee/following{/other_user}","gists_url":"https://api.github.com/users/PhilSee/gists{/gist_id}","starred_url":"https://api.github.com/users/PhilSee/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/PhilSee/subscriptions","organizations_url":"https://api.github.com/users/PhilSee/orgs","repos_url":"https://api.github.com/users/PhilSee/repos","events_url":"https://api.github.com/users/PhilSee/events{/privacy}","received_events_url":"https://api.github.com/users/PhilSee/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/clMathLibraries/clFFT/labels/AMD","name":"AMD","color":"ffffff"}],"state":"open","locked":false,"assignee":{"login":"bragadeesh","id":4991048,"avatar_url":"https://avatars.githubusercontent.com/u/4991048?v=3","gravatar_id":"","url":"https://api.github.com/users/bragadeesh","html_url":"https://github.com/bragadeesh","followers_url":"https://api.github.com/users/bragadeesh/followers","following_url":"https://api.github.com/users/bragadeesh/following{/other_user}","gists_url":"https://api.github.com/users/bragadeesh/gists{/gist_id}","starred_url":"https://api.github.com/users/bragadeesh/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/bragadeesh/subscriptions","organizations_url":"https://api.github.com/users/bragadeesh/orgs","repos_url":"https://api.github.com/users/bragadeesh/repos","events_url":"https://api.github.com/users/bragadeesh/events{/privacy}","received_events_url":"https://api.github.com/users/bragadeesh/received_events","type":"User","site_admin":false},"milestone":null,"comments":4,"created_at":"2015-02-26T19:55:45Z","updated_at":"2015-02-27T14:42:17Z","closed_at":null,"body":"Hi,\r\n\r\nwe're testing clFFT 2.2 on our Radeon HD 4670 card and are experiencing some problems: For the generated FFT kernel our OpenCL runtime (Catalyst 13.9, APP SDK 2.8.1) reports a maximum work group size of 32. However, as far as I could see in the sources, a minimum work group size of 64 or higher is coded by the kernel generators. \r\n\r\nUnfortunately this totally prevents clFFT from executing on our Radeon 4670, the client test program stops with an insufficient resources error.\r\n\r\nSo, without knowing much about the internals of the FFT kernels: Would it be possible to set down the required work group size to 32 in the kernel generators? In our application we would need two-dimensional FFTs with block sizes ranging from 64x64 to 256x256.\r\n\r\nWe are aware that the Radeon 4600 family nowadays is a legacy core with limited resources, stemming from the early days of OpenCL support on Radeon GPUs. However, we eventually would use the FFT on a long-running embedded E4690 platform and it would be really great to have the FFT capability on this core.\r\n\r\nThanks,\r\nPhilipp"},"comment":{"url":"https://api.github.com/repos/clMathLibraries/clFFT/issues/comments/76404425","html_url":"https://github.com/clMathLibraries/clFFT/issues/67#issuecomment-76404425","issue_url":"https://api.github.com/repos/clMathLibraries/clFFT/issues/67","id":76404425,"user":{"login":"PhilSee","id":11217251,"avatar_url":"https://avatars.githubusercontent.com/u/11217251?v=3","gravatar_id":"","url":"https://api.github.com/users/PhilSee","html_url":"https://github.com/PhilSee","followers_url":"https://api.github.com/users/PhilSee/followers","following_url":"https://api.github.com/users/PhilSee/following{/other_user}","gists_url":"https://api.github.com/users/PhilSee/gists{/gist_id}","starred_url":"https://api.github.com/users/PhilSee/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/PhilSee/subscriptions","organizations_url":"https://api.github.com/users/PhilSee/orgs","repos_url":"https://api.github.com/users/PhilSee/repos","events_url":"https://api.github.com/users/PhilSee/events{/privacy}","received_events_url":"https://api.github.com/users/PhilSee/received_events","type":"User","site_admin":false},"created_at":"2015-02-27T14:42:16Z","updated_at":"2015-02-27T14:42:16Z","body":"Hi, \r\n\r\nthanks a lot for the information and your hints. I set up a clFFT build environment based on the latest develop branch commit and made the changes you suggested. Unfortunately that didn't do the trick entirely, clfftBakePlan still doesn't seem to be too happy with the work group sizes.\r\n\r\nI will do some further experimentation on this issue. Meanwhile the clinfo output and clfft-client's cli output (new build with work group sizes already set to 32) are available via a separate gist repo:\r\n\r\nhttps://gist.github.com/PhilSee/ed046f0dd3e73bfa39f6"}}