[L4D2] [nVidia] Massive performance drop after a while

[sulix]

While the game usually runs with pretty good performance (~30fps), it drops to ~2fps after a while (usually a few minutes). I'm running nVidia 313.30, on a GeForce 9600GT w/ 512 MB. I've been running everything on highest, where the problem is quite reproducible. Resetting the renderer (by changing MSAA settings) seems to hold it off for a bit. Most particularly, I have thus far only been able to reproduce this with MSAA enabled. Running with MSAA off and without vsync seems to avoid it: perhaps I'm just running out of video ram or something.

Stack trace:

Thread 22 (Thread 0xf5435b40 (LWP 20890)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf75e9c33 in pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_timedwait.S:250
#2  0xf75ea25c in __pthread_cond_timedwait_2_0 (cond=0x8e803f8, mutex=0x8e80404, abstime=0xf54352a4) at old_pthread_cond_timedwait.c:55
#3  0xf729ecb4 in ?? () from /usr/lib32/nvidia-313/libGL.so.1

Thread 21 (Thread 0xf3d03b40 (LWP 20891)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf75e9c33 in pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_timedwait.S:250
#2  0xf4c12e78 in CThreadSyncObject::Wait(unsigned int) () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libtier0.so
#3  0xf49a2e1b in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libvstdlib.so
#4  0xf4c134b8 in CThread::ThreadProc(void*) () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libtier0.so
#5  0xf75e5d78 in start_thread (arg=0xf3d03b40) at pthread_create.c:311
#6  0xf751c3de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 20 (Thread 0xf3affb40 (LWP 20892)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf75e9c33 in pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_timedwait.S:250
#2  0xf4c12e78 in CThreadSyncObject::Wait(unsigned int) () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libtier0.so
#3  0xf49a2e1b in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libvstdlib.so
#4  0xf4c134b8 in CThread::ThreadProc(void*) () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libtier0.so
#5  0xf75e5d78 in start_thread (arg=0xf3affb40) at pthread_create.c:311
#6  0xf751c3de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 19 (Thread 0xe50bfb40 (LWP 20904)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf75e9c33 in pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_timedwait.S:250
#2  0xf4c12e78 in CThreadSyncObject::Wait(unsigned int) () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libtier0.so
#3  0xe8cf14c2 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/chromehtml.so
#4  0xe8cf1b11 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/chromehtml.so
#5  0xf4c13419 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libtier0.so
#6  0xf75e5d78 in start_thread (arg=0xe50bfb40) at pthread_create.c:311
#7  0xf751c3de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 18 (Thread 0xe46ffb40 (LWP 20905)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf75e984b in pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_wait.S:187
#2  0xe644da99 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#3  0xe644ec80 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#4  0xe644ecce in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#5  0xe6436702 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#6  0xe64322d0 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#7  0xe6432479 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#8  0xe6451927 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#9  0xe64519d2 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#10 0xe6450c22 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#11 0xf75e5d78 in start_thread (arg=0xe46ffb40) at pthread_create.c:311
#12 0xf751c3de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 17 (Thread 0xe3efeb40 (LWP 20906)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf75ebbf5 in sem_wait@@GLIBC_2.1 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/sem_wait.S:79
#2  0xe6df1436 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#3  0xe6d32bcf in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#4  0xe6df18d3 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
---Type <return> to continue, or q <return> to quit---
#5  0xe6df159f in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#6  0xf75e5d78 in start_thread (arg=0xe3efeb40) at pthread_create.c:311
#7  0xf751c3de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 16 (Thread 0xe36fdb40 (LWP 20907)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf75e9c33 in pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_timedwait.S:250
#2  0xf75ea25c in __pthread_cond_timedwait_2_0 (cond=0xe4707e00, mutex=0xe4707e0c, abstime=0xe36fd2a4) at old_pthread_cond_timedwait.c:55
#3  0xf729ecb4 in ?? () from /usr/lib32/nvidia-313/libGL.so.1

Thread 15 (Thread 0xe2efcb40 (LWP 20908)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf7517377 in syscall () at ../sysdeps/unix/sysv/linux/i386/syscall.S:29
#2  0xe6b7e797 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#3  0xe6b7e1c1 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#4  0xe6b7c61d in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#5  0xe640839a in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#6  0xe64322d0 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#7  0xe6432479 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#8  0xe6451927 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#9  0xe64519d2 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#10 0xe6450c22 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#11 0xf75e5d78 in start_thread (arg=0xe2efcb40) at pthread_create.c:311
#12 0xf751c3de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 14 (Thread 0xe26fbb40 (LWP 20909)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf7514301 in select () at ../sysdeps/unix/syscall-template.S:81
#2  0xe642a1d6 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#3  0xe6450be1 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#4  0xe642ec0d in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#5  0xe642f719 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#6  0xe6434a88 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#7  0xe6435050 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#8  0xe64366bb in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#9  0xe64322d0 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#10 0xe6432479 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#11 0xe6451927 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#12 0xe64519d2 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#13 0xe6450c22 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#14 0xf75e5d78 in start_thread (arg=0xe26fbb40) at pthread_create.c:311
#15 0xf751c3de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 13 (Thread 0xe1efab40 (LWP 20910)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf7517377 in syscall () at ../sysdeps/unix/sysv/linux/i386/syscall.S:29
#2  0xe6b7e797 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#3  0xe6b7e1c1 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#4  0xe6b7c61d in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#5  0xe640839a in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#6  0xe64322d0 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#7  0xe6432479 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#8  0xe6451927 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#9  0xe64519d2 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#10 0xe6450c22 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#11 0xf75e5d78 in start_thread (arg=0xe1efab40) at pthread_create.c:311

#12 0xf751c3de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 12 (Thread 0xe16f9b40 (LWP 20911)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf7517377 in syscall () at ../sysdeps/unix/sysv/linux/i386/syscall.S:29
#2  0xe6b7e797 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#3  0xe6b7e1c1 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#4  0xe6b7c61d in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#5  0xe640839a in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#6  0xe64322d0 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#7  0xe6432479 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#8  0xe6451927 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#9  0xe64519d2 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#10 0xe6450c22 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#11 0xf75e5d78 in start_thread (arg=0xe16f9b40) at pthread_create.c:311
#12 0xf751c3de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 11 (Thread 0xe0ef8b40 (LWP 20912)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf75e984b in pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_wait.S:187
#2  0xe644da99 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#3  0xe644ec80 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#4  0xe644ecce in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#5  0xe6436702 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#6  0xe64322d0 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#7  0xe6432479 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#8  0xe6451927 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#9  0xe64519d2 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#10 0xe6450c22 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libcef.so
#11 0xf75e5d78 in start_thread (arg=0xe0ef8b40) at pthread_create.c:311
#12 0xf751c3de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 10 (Thread 0xd5dcfb40 (LWP 20914)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf750ced0 in __GI_ppoll (fds=0x93d0aa0, nfds=2, timeout=<optimised out>, sigmask=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:57
#2  0xda0d58bb in pa_mainloop_poll () from /home/david/Steam/ubuntu12_32/steam-runtime/i386/usr/lib/i386-linux-gnu/libpulse.so.0
#3  0xda0d6077 in pa_mainloop_iterate () from /home/david/Steam/ubuntu12_32/steam-runtime/i386/usr/lib/i386-linux-gnu/libpulse.so.0
#4  0xf4442379 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libSDL2-2.0.so.0
#5  0xf43b7395 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libSDL2-2.0.so.0
#6  0xf4404bf0 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libSDL2-2.0.so.0
#7  0xf44522e7 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libSDL2-2.0.so.0
#8  0xf75e5d78 in start_thread (arg=0xd5dcfb40) at pthread_create.c:311
#9  0xf751c3de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 9 (Thread 0xd526bb40 (LWP 20918)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf75e9c33 in pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_timedwait.S:250
#2  0xf4c12e78 in CThreadSyncObject::Wait(unsigned int) () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libtier0.so
#3  0xf49a2e1b in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libvstdlib.so
#4  0xf4c134b8 in CThread::ThreadProc(void*) () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libtier0.so
#5  0xf75e5d78 in start_thread (arg=0xd526bb40) at pthread_create.c:311
#6  0xf751c3de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 8 (Thread 0xc73ffb40 (LWP 20919)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf75e9c33 in pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_timedwait.S:250
#2  0xf4c12e78 in CThreadSyncObject::Wait(unsigned int) () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libtier0.so
#3  0xf19867ef in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/engine.so
#4  0xf4c134b8 in CThread::ThreadProc(void*) () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libtier0.so
#5  0xf75e5d78 in start_thread (arg=0xc73ffb40) at pthread_create.c:311
#6  0xf751c3de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 7 (Thread 0xc49ffb40 (LWP 20924)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf7514301 in select () at ../sysdeps/unix/syscall-template.S:81
#2  0xee3c5abf in ?? () from /home/david/Steam/linux32/steamclient.so
#3  0xee3c9643 in ?? () from /home/david/Steam/linux32/steamclient.so
#4  0xee3ca1f8 in ?? () from /home/david/Steam/linux32/steamclient.so
#5  0xeeb17da8 in ?? () from /home/david/Steam/linux32/steamclient.so
#6  0xeeb169ca in ?? () from /home/david/Steam/linux32/steamclient.so
#7  0xeeb16c2f in ?? () from /home/david/Steam/linux32/steamclient.so
#8  0xeeb18963 in ?? () from /home/david/Steam/linux32/steamclient.so
#9  0xf75e5d78 in start_thread (arg=0xc49ffb40) at pthread_create.c:311
#10 0xf751c3de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 6 (Thread 0xc5350b40 (LWP 20925)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf75e9c33 in pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_timedwait.S:250
#2  0xeeb19ccf in ?? () from /home/david/Steam/linux32/steamclient.so
#3  0xeeaf6740 in ?? () from /home/david/Steam/linux32/steamclient.so
#4  0xeeb17da8 in ?? () from /home/david/Steam/linux32/steamclient.so
#5  0xeeb169ca in ?? () from /home/david/Steam/linux32/steamclient.so
#6  0xeeb16c2f in ?? () from /home/david/Steam/linux32/steamclient.so
#7  0xeeb18963 in ?? () from /home/david/Steam/linux32/steamclient.so
#8  0xf75e5d78 in start_thread (arg=0xc5350b40) at pthread_create.c:311
#9  0xf751c3de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 5 (Thread 0x90dffb40 (LWP 20926)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf74e4bb6 in nanosleep () at ../sysdeps/unix/syscall-template.S:81
#2  0xf7514d5d in usleep (useconds=10000) at ../sysdeps/unix/sysv/linux/usleep.c:32
#3  0xeeb182b2 in ?? () from /home/david/Steam/linux32/steamclient.so
#4  0xee961aee in ?? () from /home/david/Steam/linux32/steamclient.so
#5  0xeeb17da8 in ?? () from /home/david/Steam/linux32/steamclient.so
#6  0xeeb169ca in ?? () from /home/david/Steam/linux32/steamclient.so
#7  0xeeb16c2f in ?? () from /home/david/Steam/linux32/steamclient.so
#8  0xeeb18963 in ?? () from /home/david/Steam/linux32/steamclient.so
#9  0xf75e5d78 in start_thread (arg=0x90dffb40) at pthread_create.c:311
#10 0xf751c3de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 4 (Thread 0x90cfeb40 (LWP 20927)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf75e9c33 in pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_timedwait.S:250
#2  0xf75ea25c in __pthread_cond_timedwait_2_0 (cond=0x19fe5340, mutex=0x19fe534c, abstime=0x90cfdd64) at old_pthread_cond_timedwait.c:55
#3  0xf729ecb4 in ?? () from /usr/lib32/nvidia-313/libGL.so.1

Thread 3 (Thread 0x90bfdb40 (LWP 20928)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf74f194c in sched_yield () at ../sysdeps/unix/syscall-template.S:81
#2  0xf6833119 in ?? () from /usr/lib32/nvidia-313/libnvidia-glcore.so.313.30

Thread 2 (Thread 0xc69c1b40 (LWP 20931)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf75e9c33 in pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_timedwait.S:250
#2  0xeeb19ccf in ?? () from /home/david/Steam/linux32/steamclient.so
#3  0xeeaf6740 in ?? () from /home/david/Steam/linux32/steamclient.so
#4  0xeeb17da8 in ?? () from /home/david/Steam/linux32/steamclient.so
#5  0xeeb169ca in ?? () from /home/david/Steam/linux32/steamclient.so
#6  0xeeb16c2f in ?? () from /home/david/Steam/linux32/steamclient.so
#7  0xeeb18963 in ?? () from /home/david/Steam/linux32/steamclient.so
#8  0xf75e5d78 in start_thread (arg=0xc69c1b40) at pthread_create.c:311
#9  0xf751c3de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 1 (Thread 0xf5468700 (LWP 20889)):
#0  0xf777b430 in __kernel_vsyscall ()
#1  0xf75e9c33 in pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_timedwait.S:250
#2  0xf4c12e78 in CThreadSyncObject::Wait(unsigned int) () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libtier0.so
#3  0xf499e99f in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libvstdlib.so
#4  0xf499d0ad in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/libvstdlib.so
#5  0xf0fbcfe0 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/materialsystem.so
#6  0xf18f9de5 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/engine.so
#7  0xf190c0ab in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/engine.so
#8  0xf190ea4c in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/engine.so
#9  0xf1926340 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/engine.so
#10 0xf19265ae in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/engine.so
#11 0xf19266b9 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/engine.so
#12 0xf1a0bd13 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/engine.so
#13 0xf1a0811c in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/engine.so
#14 0xf1a0822f in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/engine.so
#15 0xf1a79050 in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/engine.so
#16 0xf1a09a8f in ?? () from /space/SteamLibrary/SteamApps/common/Left 4 Dead 2 Beta/bin/engine.so
#17 0xf4aa0b00 in ?? ()
#18 0xf4aa0b00 in ?? ()
#19 0xf4a8826d in ?? ()
#20 0x080484e4 in main ()

Steam info:

Information:
    Vendor:  GenuineIntel
    Speed: 2394 Mhz
    2 logical processors
    2 physical processors
    HyperThreading:  Unsupported
    FCMOV:  Supported
    SSE2:  Supported
    SSE3:  Supported
    SSSE3:  Supported
    SSE4a:  Unsupported
    SSE41:  Unsupported
    SSE42:  Unsupported

Network Information:
    Network Speed:  

Operating System Version:
    Ubuntu 13.04 (64 bit)
    Kernel Name:  Linux
    Kernel Version:  3.8.0-19-generic
    X Server Vendor:  The X.Org Foundation
    X Server Release:  11303000
    X Window Manager:  KWin
    Steam Runtime Version:  steam-runtime-release-i386_2013-04-16

Video Card:
    Driver:  NVIDIA Corporation GeForce 9600 GT/PCIe/SSE2

    Driver Version:  3.3.0 NVIDIA 313.30
    Desktop Color Depth: 24 bits per pixel
    Monitor Refresh Rate: 59 Hz
    VendorID:  0x10de
    DeviceID:  0x622
    Number of Monitors:  2
    Number of Logical Video Cards:  1
    Primary Display Resolution:  1440 x 900
    Desktop Resolution: 2880 x 900
    Primary Display Size: 16.14" x 10.24"  (19.09" diag)
                                            41.0cm x 26.0cm  (48.5cm diag)
    Primary Bus: PCI Express 16x
    Primary VRAM: 512 MB
    Supported MSAA Modes:  2x 4x 8x 16x 

Sound card:
    Audio device: SigmaTel STAC9227

Memory:
    RAM:  7920 Mb

Miscellaneous:
    UI Language:  English
    LANG:  en_AU.UTF-8
    Microphone:  Not set
    Total Hard Disk Space Available:  65577 Mb
    Largest Free Hard Disk Block:  6064 Mb

I am also noticing this in a slightly different way. If I set textures and shading to low I don't see any performance decline with 4x anisotropy, no antialiasing. This is contradictory to my Portal (Beta) setup which takes the defaults + multicore rendering and doesn't flinch. Multicore is also on for l4d 2 and I remember Windows binaries having issues with that setting. It doesn't look like you can turn it off and I'm not sure if that is because I have SLI enabled.

Processor Information:
Vendor: AuthenticAMD
Speed: 3200 Mhz
3 logical processors
3 physical processors
HyperThreading: Unsupported
FCMOV: Supported
SSE2: Supported
SSE3: Supported
SSSE3: Unsupported
SSE4a: Supported
SSE41: Unsupported
SSE42: Unsupported

Operating System Version:
Linux Mint 13 Maya (64 bit)
Kernel Name: Linux
Kernel Version: 3.2.0-41-generic
X Server Vendor: The X.Org Foundation
X Server Release: 11103000
X Window Manager: Marco
Steam Runtime Version: steam-runtime-release-i386_2013-04-16

Video Card:
Driver: NVIDIA Corporation GeForce 8500 GT/PCIe/SSE2

Driver Version:  3.3.0 NVIDIA 304.88
Desktop Color Depth: 24 bits per pixel
Monitor Refresh Rate: 60 Hz
VendorID:  0x10de
DeviceID:  0x421
Number of Monitors:  1
Number of Logical Video Cards:  2
Primary Display Resolution:  1920 x 1080
Desktop Resolution: 1920 x 1080
Primary Display Size: 20.04" x 11.26"  (22.95" diag)
                                        50.9cm x 28.6cm  (58.3cm diag)
Primary Bus: PCI Express 16x
Primary VRAM: 512 MB
Supported MSAA Modes:  2x 4x 8x 16x 

Memory:
RAM: 16050 Mb

[ZeXx86]

I guess this is same issue as in TF2 - #23
I am also affected in L4D2 as well as in TF2.
While I am playing with High settings VRAM usage on my GPU is nearly 100%. Sometimes game is running super smooth, sometimes it is only around 20FPS (10 with composition). GeForce 8800 / nvidia 313 driver / Ubuntu 13.04 64bit.

[sulix]

Yeah: I had a look with nvidia-smi while playing. The game has the GPU memory usage pegged at 90-100% all the time, and there is no correlation between VRAM use and performance.

[ZeXx86]

I think this problem appear when VRAM memory exceeds 100%, then it does not matter what usage is and game is slow.

I can confirm this. This issue is much less prevalent when running the game in a separate x server, where high frames (100+) are consistent. I like running my games in a separate X server, but it seems silly that it's required for me to maintain high FPS.

[Tinche]

I'm affected by this as well (Left 4 Dead 2, Nvidia GPU). I'd be willing to help in debugging if necessary.

[nickpelone]

Seconded. I am affected by this in both TF2 and L4D2, and would love to see this fixed. I can reply with any further information needed.(Nvidia GT650M with bumblebee, all driver versions affected)

[xraynorm]

I had a similar issues to this, it turned out to be a lack of vram.

ValveSoftware/steam-for-linux#237

[nickpelone]

I have 2 GB of VRAM. I highly doubt that's the issue.

[verdegr]

I confirm that bug, BUT it happens in Unigine Valley too, so POSSIBLY its NVIDIA's DRIVER problem. Not L4D2 problem.

MAYBE it is related to antialiasing because i have noticed that if you lower anisotropic and/or MSAA to x4 or lower the bug disappears.

GTX 460 768mb @ 1366x768