Introduction

This "Tweak Guide" for Quake 3: Arena is meant to help you run Quake 3 in the best possible way for the system you are currently running. Feel free to experiment with different settings and check the console guide at http://q3a.pcgame.com for more info. Here is the recommended systems for you.

HIGH
Processor: P3  733 - P2  450 [] AMD K62 450+, AMD K7 500+
RAM:256 MB - 128 MB
GRAPHICS: GeForce, TNT 2, Voodoo 3 2000 - 3500

MEDIUM
Processor: P2 400 - P2 233, Celeron 400+, AMD K62 300 to 400
RAM:96 MB - 64 MB
GRAPHICS: TNT, TNT 2 low budget, Voodoo 2, ATI Expert Series,  

LOW
Processor: P1 180 - P1 233 , Celeron 266 - 366, AMD K6 233 - 200.
RAM:32 MB - 64 MB depending on processor
GRAPHICS: Voodoo 2

Graphics

This well help you decide what's best to run on for your system to handle. The graphics may worsen or improve depending on what you select.

Display

Changing the brightness and screen size can improve performance and Frag count. Make sure you tweak this too!

Data Rate

Changing the data rate can improve performance or latency aka lag and help you Frag better.

Game Options

Changing the data rate can improve performance or latency aka lag and help you Frag better.

Console Tweaks [Graphics]

Changing these options can improve performance but will decrease graphic quality.

Console Tweaks [NET]

Changing these settings can improve your ability to see people before they see you or have a better chance of fragging them.

Thanks for help from Quake 3 Center and I Am Quake 3 for a guide to look at. All tweaks have been tested by me using 3 different systems all LOW, Medium, and High End. Here are the systems used in the testing and creation of the guide.

HIGH END Brand is IBM
Pentium 3 550Mhz
128 Megs Ram
Creative Labs TNT 2 Ultra w/ 32 Megs Ram TV OUT [Latest Drivers]
19inch Hewlett Packard Pavilion Monitor

MEDIUM END Brand is Gateway
Pentium 2 266 Mhz
64 Megs Ram
Creative Labs Voodoo 2 w/ 12 Megs Ram NOT SLI [Latest Drivers]
17inch monitor EV7000 Gateway

HIGH END Brand is Gateway
Pentium 200 Mhz
32 Megs Ram
Diamond Voodoo 2 w/ 12 Megs Not SLI [Latest Drivers]
15inch monitor EV500 Gateway

Updates!
December 29, 1999
Check the Quake III- Arena FAQ from id software for more troubleshooting!
Also check John Carmack's plan for hints on playing with modems and other such things right here.

Here is what he had to say about playing on a modem 28.8 in speed.

I have been playing a lot of Q3 on a 28.8 modem for the last several days.

I finally found a case of the stuck-at-awaiting-gamestate problem that
turned out to be a continuous case of a fragment of the gamestate getting
dropped. I have changed the net code to space out the sending of the
fragments based on rate.

Note that there have been a few different things that result in stuck
at gamestate or stuck at snapshot problems. We have fixed a few of them,
but there may well still be other things that we haven't found yet.

You can still have a fun game on a 28.8 modem. It is a significant
disadvantage, no question about it, but you can still have a good game if
you play smart. If there is someone that knows what they are doing on a
server with a ping in the low 100s, there won't usually be much you can
do, but a skilled modem player can still beat up on unskilled T1 players...

Make sure your modem rate is set correctly. If you have it set too high,
large amounts of data can get buffered up and you can wind up with multiple
seconds of screwed up delays.

Only play on servers with good pings. My connection gives me a couple dozen
servers with mid 200 pings. 56k modems often see servers with sub 200 pings.
If you ignore the ping and just look for your favorite map, you will probably
have a crappy game.

If you have a good basic connection to the server, the thing that will mess
up your game is too much visible activity. This is a characteristic of the
number of players, the openness of the level, and the weapons in use.

Don't play on madhouse levels with tons of players. None of the normal Q3
maps were really designed for more than eight players, and many were only
designed for four.

Don't play in the wide open maps unless there are only a couple other
players. Four very active players in a wide open area are enough to bog
down a modem connection.

I just implemented "sv_minPing" / "sv_maxPing" options so servers can restrict
themselves to only low ping or high ping players. This is done based on the
ping of the challenge response packet, rather than any in-game pings. There
are a few issues with that -- a LPB may occasionally get into a HPB server
if they happen to get a network hiccup at just the right time, and the number
used as a gate will be closer to the number shown in the server list, rather
than the number seen in gameplay. I would reccomend "sv_minPing 200" as a
reasonable breakpoint.

Easter Eggs [from gamespot]
Bring down the console (with the tilde ~ key) and type "/map test_bigbox" to load a small, rectangular arena with only the gauntlet and machine gun available. Don't expect to engage in any fierce battles here, but it's still interesting to look at. Well, actually it's not that interesting, but you can gauntlet box with your closest friends!

On Deva Station (Q3DM11), locate the teleporter placed behind a shotgun spawn spot. The teleporter, a one-way trip, takes you to a room with armor shards. Across from the teleporter and shotgun is what appears to be a simple wall. Approach the wall, touching its surface, and watch it open. Step inside for a message ("You've Found A Secret!") and grab the +50 health inside and take a look at the strange fish creature that some call The Dope Fish.

On Demon Keep (Q3DM15), enter the tunnel at the bottom of the lava pool area that leads back into the heart of the keep. Along the way, you'll spot a disembodied head, complete with freaky eyes, on the left side of the path.

On Bouncy Map (Q3DM16), fly underneath the main area of the map and spot the character from the Internet comic strip User Friendly.

On Apocalypse Void (Q3DM19), fly underneath the main area of the map and spot the same User Friendly character from Bouncey Map. Also, fly around to the large antenna and spot another logo for the Old Man Murray web site.