I just bought myself an ATI x1950pro and an OCZ GameXStream PSU. After hooking everything up, I fired up some of my favorite games, once I got to Age of Empires 3, I noticed my performance was actually worse then my aging 7800gs. No other game has this issue (except for Quake 4, which is obviously favored by the GeForce 7 series). I already created a post in the pc games thread and wasn't getting much of a response, suggested by another poster, so I'll just give you a link to the original thread.
I know exactly what you are talking about. I built a computer for a friend of mine recently. It has a x1900GT Video card and Game Stream 600W PSU (A great PSU by the way). But anyhow, I watched him play a demo of AOE3 and I was really taken back. It is like if you move to a different section of the map that the buildings, trees, or structures on the edge of your screen take about 1-2 seconds to generate. That ain't right for a video card that strong. It plays other games like BF2142 and GTR2 FLAWLESS with very high frame rates, beautiful contrast and color and ZERO studdering or flickering. It plays those games like a dream.
AOE3 on a x1900GT is very playable but to me long term watching that delay in the game would bug me. And he has plenty of Ram also. He is running off of 1 Gig of DDR2 800 Kingston Hyper-X. Just wanted to let you know that you are not alone. Unfortunately I do not have an answer to your problem.
Did you try going to the AOE3 website or maybe emailing them? If you find out anything please reply back to your orginal post. I am interested in the answer.
I am in a dilema right now deciding between ATI and Nvidia for my own personal PC build.
I figured something very important out. It turns out that only the expansion of AoE3 has this issue, playing the original, ran awesome. My frames in most intense scenes float around ~20fps, in non-intense scenes, ~55-65fps.
But it does not make sense. The Expansion graphically is no better than the original AOE 3. They did something to the game that is tripping up ATI cards. Maybe it is more advanced technology and just a driver update is needed. But to the best of my knowledge when my friend was playing he had all of the latest drivers.
I am beginning to think now that since Nvidia is a sponsor of AOE3 that they had the game purposely made so it would not play well on ATI cards in order to make their own cards look better (When they are not). Read this article. This really stinks.
Driver and game engine optimisation has become an increasingly sensitive issue, with hardware reviews routinely making decisions based upon performance margins of 10-20%, well within the bounds of driver influence. As a result, both ATI and nVidia are now willing to go even further to ensure popular games are optimised for their respective chip architectures. For example, NVidia sponsored Doom 3, and ATI spent a reported $6m on Half Life 2.
When Doom 3 was released, unsurprisingly nVidia held a large performance lead. ATI analysed the code, and found shader calculations were being performed manually through a look up table, to compensate for the relatively poor performance of the FX series in this respect. Through application recognition, on the x800 card ATI reportedly found a 30% speed gain, just by moving shader calculations to hardware. To this extent, the question of who has the best graphics architecture, is becoming ever harder to answer, as with the increasing complexity of GPUs, performance becomes ever more optimisation specific.
Hmm, conspiracy? Not really. Looking up the benchmarks we have already, tells a different story. In fact, X1900 cards rip it up in AoE3 The Warchiefs, this is just an isolated problem I think. The fact that the game runs fine without the expansion just makes things a whole lot more weird.
EDIT: Doom 3 isn't the only bad example either. Look into more recent games, and check out NFS Carbon. Nvidia hardware can't run that game at all. Even the x1950xtx matches performance of the 8800gts in Carbon. The 8800gts should run that game 1.5x faster then the x1950xtx in ratio comparison to most other games.