if you "don't know the technicalities" 

a lot of factors involved here, but I'd suspect that your vsynch was enabled if your fps wasn't affected by a significantly newer gfx card when using a GL-engine.

I believe Q3 can control vsynch itself, but with many older engines you'll have to disable it manually to get past the monitor refresh rate of 60-85 Hz. The latest FQ can also do this, I think.

Another issue is hardcoded (or cvar controlled) max_fps of 75-100 in many engines while playing (not during timedemos of course).

If you by "qw" means QuakeWorld software renderer, well then I believe very little is (or even could be) used of the gfx hardware to help fps. 

of course I had vsync off.

I don't remember if it was glqwcl or fuhquake-gl.

This questioning seems pointless since the people with the most knowledge about the subject here (or anywhere) are engine coders having their own spoon in the soup or however you're supposed to say that.

I haven't bothered to download nexuiz but from what I've heard (from decent players that actually notice things), it's significantly slower than q3, even with the special effects turned off.

But whatever. Gluing stuff into q1 is just not the only way, and I'm trying to gather a picture of how hard the OTHER WAY would be. 

for example buying a new graphics card didn't improve my qw frame rate much at all!

Not that this helps much, but this could also mean that your performance was already CPU limited. 

Or that he hit a hard limit in the visual improvement... in quakeworld, servers limit the frames per second to 77, so a 400$ graphics card is not going to help you unless you are REALLY pushing it. The stresses could maybe come from something like tenebrae (slow and complex), but in general, clients optimized for displaying essentially the same thing as glqwcl.exe are not going to really need a turbocharged 4x dragon graphics card to reach acceptable, or even outstanding, performance. The mathematical demands placed on the card are just not high enough, because the core of the visual rendering engine is still from 1995, and thus easily handled by modern mediocre cards.

My 2 cents... engine coders, please correct me on my probable mistakes ;) 

it was cpu limited, unlike q3, which was gpu limited. 

And isn't that the point of the discussion? That the Quake renderer is heavily CPU dependent and therefore can't take advantage of the power of modern video cards, whereas q3 can?

That efficiency would come in handy if people are going to make ambitious maps like Marcher. 

we have an average or a little above dm map for quake and then a similar map for q3. Take your current computer, tune the settings of the games so they both look approximately similar. Have some medium-detail textures and dynamic lights on, but no muzzleflash or rocketlight. Fairly small explosion effects. Put the q3 server fps to 72 too.(?) Play some dm and check the timedemos.

Now in which engine is a higher stable fps achievable? How high is it? Why?

I don't have q3 now, but even 5 years ago when cpu power was still bigger compared to gpu power, they were roughly similar in speed. 

yeah that's what I meant!
Although I'm not sure if that is the only difference. The games have been designed on somewhat different assumptions on available hardware, map size and complexity and whatnot... 

Ooh ooh ooh. Speedy, go fuck yourself, I would love to play Q1SP's in the Quake3 engine.

Hell, I would love even more to BUILD them for Quake3.

Oh this is getting me hard. 

why don't you build some Q3SPs for the Quake3 engine? 

I have this great idea for a desert-themed Q3SP partial conversion! Maybe you should join me! 

the engine would have to be modified so maps would look... faithful. Decent. Good. Not Q3. You know. At least some of you. Maybe.

I feel like I'm missing something here.

I've heard from a quake coding guy that the main difference in the maps is (q1 maps in q3) collision detection. Don't know if q3 then uses that q1-like multiple hull system or what. There prolly aren't monster hulls in q3. And the mods/licences with monsters aren't open-source, right?