jasonb885:
Give it a try, both ways.
Download DirectX Tweaker, and save it back to a folder. Doesn't make a difference where.
Run the game at default settings, and use
FRAPS to check your frame-rates. There's also some kind of frame rate control for SH3, but FRAPS will let you
log your framerates, and give you a running average. Mess around with the external camera, spend some time drawing pretty lines on the nav-map. Take a run through the english channel at high time compression.
Then use DirectX Tweaker. You have to "add new entry", and point it to "d:\games\sh3\sh3.exe", or whatever. Make sure you tick the "active" box (which records your settings to the registry). Then select at least "Force Shader P"; I also select "high priority", for what it's worth (it only priorities I/O, not processing). You will find that explosions have
BLUE in them, rather than the usual red and orange. Kind of looks cool, like vivid burning ethanol, but highly un-realistic. I haven't used DXT much, but I could immediately tell the difference on the nav-map, specifically at high time compression through the English Channel. And I could tell a color-gradient difference on the sea depths, making them MUCH more readable (greater color contrast between depth zones).
Like I said, the only real graphic anomaly that I noticed was the fires/explosions. For people with slower cards (5900, 5950U, 6600), the performance difference should be fairly large. Whatever it is about the nav-map, I have absolutely no idea, but it responds to increased graphics processing power...