Please try using the proprietary AMD driver.
I tried the one in "Additional Drivers" and also the one on the official AMD website without success. It was actually breaking my dual monitor setup and even with the command line tool "amdconfig" I couldn't go too far. Even trying to open Catalyst threw me an error.
I can confirm a huge frame rate drop while using open-source driver. I got about ~10-15 FPS whereas with proprietary driver I got a lot more (not sure exactly, but everything was running smoothly). Unfortunately this is probably a problem of the open-source driver, not Steam. And yes, proprietary driver is crap, especially with multi-monitor setup. :)
Tested on Debian x86_64 with Gallium 0.4 on AMD CEDAR and mesa 9.1 devel 9.0.x.
I am use latest (from git) open source radeon driver with 3.7 kernel+DMA async patch and have more than 80 FPS.
OpenGL renderer string: Gallium 0.4 on AMD BARTS
OpenGL version string: 3.0 Mesa 9.1-devel (git-cb3b172)
OpenGL shading language version string: 1.30
DMA async patch?
DMA async patch?
I have the same issue, but WITH ATI legacy 13.1 INSTALLED.
I'm providing my graphics card section:
Video Card:
Driver: ATI Technologies Inc. ATI Mobility Radeon HD 3400 Series
Driver Version: 3.3.11672 Compatibility Profile Context
Desktop Color Depth: 24 bits per pixel
Monitor Refresh Rate: 60 Hz
VendorID: 0x1002
DeviceID: 0x95c4
Number of Monitors: 1
Number of Logical Video Cards: 1
Primary Display Resolution: 1280 x 800
Desktop Resolution: 1280 x 800
Primary Display Size: 13,03" x 8,15" (15,35" diag)
33,1cm x 20,7cm (39,0cm diag)
Primary VRAM Not Detected
I am running at 720x480 at the moment. In Windows, I could use full resolution - 1280x800.
MAJOR FRAMERATE LOSS:
Major framerate loss occurs when aiming at large number of ḿodels - This mostly happened to me when played Man Vs Machine gametype, with lots of animated models. Aiming to direction without any players / bots increases FPS.
Last, I am providing System info.
Operating System Version:
Linux Mint 13 Maya (64 bit)
Kernel Name: Linux
Kernel Version: 3.2.0-23-generic
X Server vendor: The X.Org Foundation
X Server release: 11103000
Issue transferred to ValveSoftware/Source-1-Games#42.
This issue is closed - continue conversation there.
Nothing extracted yet.
I tried to play, but with that speed, I can't. It is working well on Windows, so not an Hardware issue.
Thanks