Hi Alex, today I searched the web to find some specs regarding the BARTS LE chipset of the HD 6790 cards. I found three references that contain useful information:
http://ht4u.net/reviews/2011/amd_radeon_hd_6790_barts_le_im_test/index2.php http://www.nordichardware.com/news/71-graphics/42743-exclusive-radeon- hd-6790-based-on-barts-le-with-800-sps.html http://www.tomshardware.de/Radeon-HD6790-Test-Benchmark- Review,testberichte-240757-2.html I collected all useful specs and can give you a summary now. For a Radeon HD 6790 with BARTS LE, these specs are given: Stream processors (Vec5): 160 Shader ALUs: 800 = 160*Vec5 Shader type: Vec5 (Co Issue 1:1:1:1:1) Capabilities per Shader: MADD Double Precision: no Texture Units (TMUs): 40 Raster Operation (ROP): 16 Shader Model Version: 5.0 DirectX 11 Output: 2 Render Backends (instead of 4), with 8 ROPs each SIMD-Cluster (Streaming Multiprocessor) "SM-Units": 10 per SIMD-Cluster: 16 Vec5 ALUs Per SIMD-Cluster: 1 Quad-TMU (=4 TMUs), 40 in total If I look at the patched file evergreen.c, I see that the specs do not match yet. For example, the number of SIMDS is defined as 5 in the source, but the references tell me that the BARTS LE has 10. Additionally, I tried 3.2-rc5 today, showing the same does-not-boot behavior as before. However, setting num_ses to "1" makes sense in terms of calculating max_backends as num_ses * 2, as the BARTS LE has only 2 backends available. Unfortunately, it doesn't work here with a setting of "1" for num_ses. I can't assign the other variables in the source code, as I have no idea what "max_pipe", "max_tile_pipes" and other statements such as the famous "backend_map" mean... Hope you can correct some of the settings? :-) Regards, Florian -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-ati in Ubuntu. https://bugs.launchpad.net/bugs/840140 Title: Graphical corruption then black screen using an ATI Radeon 6790 card on boot To manage notifications about this bug go to: https://bugs.launchpad.net/xserver-xorg-driver-ati/+bug/840140/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp
