I can't disable vsync. Neither gl_vsync 0 or unchecking option "Wait for vertical sync" disables vsync. I have vblank_mode set to 0. Tested in Counter-Strike 1.6.

System info:

Processor Information:
Vendor: GenuineIntel
Speed: 2400 Mhz
4 logical processors
2 physical processors
HyperThreading: Supported
FCMOV: Supported
SSE2: Supported
SSE3: Supported
SSSE3: Supported
SSE4a: Unsupported
SSE41: Supported
SSE42: Supported

Network Information:
Network Speed:

Operating System Version:
"Arch Linux" (64 bit)
Kernel Name: Linux
Kernel Version: 3.8.5-1-ARCH
X Server Vendor: The X.Org Foundation
X Server Release: 11400000
X Window Manager: Compiz
Steam Runtime Version: steam-runtime-release-i386_2013-03-25

Video Card:
Driver: Intel Open Source Technology Center Mesa DRI Intel(R) Ironlake Mobile x86/MMX/SSE2

Driver Version:  2.1 Mesa 9.1.1
Desktop Color Depth: 24 bits per pixel
Monitor Refresh Rate: 59 Hz
VendorID:  0x8086
DeviceID:  0x46
Number of Monitors:  1
Number of Logical Video Cards:  1
Primary Display Resolution:  1440 x 900
Desktop Resolution: 1440 x 900
Primary Display Size: 11,93" x 7,48"  (14,06" diag)
                                        30,3cm x 19,0cm  (35,7cm diag)
Primary VRAM Not Detected

Sound card:
Audio device: Intel IbexPeak HDMI

Memory:
RAM: 3815 Mb

Miscellaneous:
UI Language: English
LANG: en_US.UTF-8
Microphone: Not set
Total Hard Disk Space Available: 47491 Mb
Largest Free Hard Disk Block: 10266 Mb

Installed software:

Recent Failure Reports: