Doom3's onscreen polygons are actualy closer to the 250,000 mark - but as technically non are textured and actually pixel textured which can only be used by GeForce3,4 and Radeon 9700 and done on a single sublayer of the processor (kinda like the Math CoPro in most x86 after Pentium) it actually runs nice and nippy on a 1Ghz
with DarkBasic i've found that you can actually oftenly match polygon for polygon on the software render engines of Quake2 and Half-Life - really you just have to know howto spend them better, as i've noted Half-Life's ONSCREEN was never more than 6,000 even with a boss onscreen, because they knew howto setup properly.
However it probably is a thought to know that Quake3 doesn't actually have that many onscreen at one either!
1,200 for generally levels (on high detail) - characters right up close under 1,000 each... weaponry under 500 each
generally you'll always have under 10,000 even in that!
you'll notice it lag when you have higher count models in there ... i mean i can run it quite nicely on my Duron800 - GF2 mx 200 - 512Mb Ram @ 800x600x32bpp high details
it does look nice, but also one the later levels with around 6warriors - my FPS will go from 65->25 ... still playable but not really what i'd prefer.
Also take into account polygons aren't all you have onscreen, i mean i can push almost 250,000 polygons in DB within a single object untextured at 60fps just having the object move using the cursors - however textured, and this drops to around 95,000 - add animations 50,000 - add Ai 20,000 - add networking 7,500
i mean for me thats WAY more than enough to do something decent with ... but depending on what needs to be done per loop depends on the speed.
thanks to DBpro's compiled multithreading of code this is extended a great deal, but stil very dependant on how you use them AND how you code things.
Better programmers can push more polys than those who purely rely on DB's builtin functions
Better Artists can understand what polygons need to be where, and howto use them wisely to give best possible graphics leaving more speed free for coders...
when both work together well, the posibilities are endless
Anata aru kowagaru no watashi! 
