I checked your cfg - first of all change com_hunkmegs to 256, com_maxfps to 125 (there is no need to have more than this), set com_soundmegs to 192. You need to check megs settings because they are depending on your memory size. For me personally i change rate to 45000. Try set r_primitive to 2. I dont know what is the limit for megs cvars but i was forced to set them on shortcut because if i was doing this in game i had them latched.
This is my shortuct: D:\Gry\ET\etl.exe +set com_hunkmegs 512 +set com_zonemegs 64 +set com_soundmegs 512
If you set to much of megs you will get error that something cannot allocate.