https://bugs.freedesktop.org/show_bug.cgi?id=76490
--- Comment #39 from Alex Deucher alexdeucher@gmail.com --- (In reply to Tobias Droste from comment #35)
- This card works fine with any sclk/mclk combination with the same vddc
(1238mV) in windows and I can overclock there!
There is apparently some aspect of the set up that we are not programming correctly that manifests with higher clocks on certain boards.
I'm also wondering why I get a different VBIOS size if I get the bios in windows (gpu-z) and linux. Is it because different firmware gets loaded? The (working) vbios under windows is twice as large as the linux one (see attachments).
The vbios is loaded from rom on the card. The firmware for the various micro-controllers on the GPU are loaded by the driver and are not part of the vbios. I'm not sure off hand why they differ. Perhaps gpuz always returns a 128K image regardless of what size the actual bios is? Or maybe it asks the driver windows driver for a copy and the windows driver always stores 128K images regardless of the actual image size. I quick look at the tables and I only see one small difference in the overdrive table: -OD max sclk: 140000, max mclk: 162500 (win) +OD max sclk: 107000, max mclk: 140000 (linux) Everything else appears to be the same. I'm guessing the windows driver patched that and gpuz fetches the copy from the driver.