Be sure it's not a hardware issue.
Turn on the FPS HUD/display to see your FPS. (sorry, don't know command, searchable on google)
See if low FPS is linked with high-ping.
Reason: If you're using a PC that has onboard VID and onboard LAN, then when your CPU gets 'loaded', it hasn't got enough power to keep the VID and LAN up to 100%
Solution: Install Video card, takes load off CPU and frees up RAM. Install LAN card, again, takes the load off CPU
When your PC has to 'render' a 'scene', the CPU has to do all the 'computing'. If you have a video card, the GPU does that job and leaves the CPU to take care of 'the rest of the overhead' (ie. disk reads/writes, RAM transfers, math/calculations, etc)
Vid card first, then check, then add LAN card. Taking the VID load off CPU may be enough to get onboard-LAN to work at 100%.
Run ET in the lowest rez (800x600?) possible, check the FPS, then try 1028x768/700 or like, and see if large change in FPS.
(Delord once told me that he ran in 800x600 for best 'aiming/hits'. I tried that but didn't like the 'blocky grfx, so I run next one up, 1028x700/768 (700 something, don't quite remember atm)
A higher rez = more load on CPU/GPU, choppier grfx, lower FPS, more RAM req'd
also: (until u tell us your hardware, don't know what you have) Some VID cards are 'optimized' for a particular resolution (rez). So a beefy card could actually have 'trouble' running lower rez (800x600/1028x768), and set to the optimum rez (1920x1080 etc), you will get higher FPS.
So first thing to do is turn on FPS, and then if you have onboard VID&LAN, you'll need to install addon-cards.
Eliminate the 'hardware' before you go 'mucking around in ET configs'.
Your configs in router can also be an issue. Check PC hardware first
One setting to be sure to change in ET is 'sync vertical screen'. Turn it off
With it 'off', you will get 'screen tearing', but it will be smoother. With it turned 'on', your PC must 'wait' for the video to be rendered & displayed 'without tearing'/nice clean pic.
Mine is off, I see very little 'tearing' (pronounced: tare-ring, ie. ripping).
Also, check your ping with speedtest.com
That will give you a ping with low CPU load, help determine if high-CPU load is causing bad ping
Turn on FPS display, do a ping test outside of ET, turn off 'screen synch, and give us a list of hardware you're using (the Devil is in the details).
my 2c, short version
edit: speedtest ping
Check your speedtest ping.
Then check QAW server ping 'outside of gameplay'.
I have an icon on my desktop I click and it starts ET and takes me directly to QAW server. (I don't know if you do the same)
You want to start ET without auto-server-join. Then PLAY ONLINE to get list of servers, and check the ping you get to QAW-server. (In the list, I get about a 40ms ping, in-game I get about 50-54ms ping). So the ping displayed to you in the list 'should' be close to what you get in gameplay, otherwise the CPU/GPU load is having an effect on your ping
edit:
Sorry, left one out, onboard sound.
In order of CPU-load;
1.onboard-vid
2.onboard-sound
3.onboard-LAN
Meaning you would install a sound-card and test before installing a LAN (NIC)-card
(Having troubles with my onboard-sound today, so looking at adding sound card is what made me think of it)
edit:
My onboard-sound 'sh*t the bed', (hope that's not too technical
)
The only card I had lying around was an old Sound Blaster Audigy. Sound is horrendous but at least it's sound.
I refuse to buy new 'computers and computer parts' due to the high depreciation. (It's not a good place to put your $$. All my computer 'stuff' is 'leftovers' from customers)
Silver lining is I should be able to squeak out a few more milliseconds on ping now that CPU hasn't got the sound-processing load on it