Upgrade using Athlon XP-M (Barton from TB)

I went from an Athlon 2800 (2250mhz 256 L2 cache) to an Athlon XP-M (2450mhz 512 L2 cache) and have noticed a lot of improvement in general computer speed. In FS2004, however, I notice quite a bit of improvment in low density scenery areas but in high density areas such as default Seattle area with everything maxed and 30 miles of visability, I notice maybe 1 frame per second increase with default C-172 and no improvement when using my beloved RFP 747-200. Is my 9800 Pro holding me back? Would I get better frames per second with a better card? I purchased the XP-M (A stepping) from NewEgg.com and it came a day earlier than expected. I also purchased Artic Silver 5 and applied it according to directions. The update was smooth, and it poped easily and fired up as is. I immediately went into the BIOS and set it at 13.5x166 (the same setting as the TB Athlon XP 2800 that I had in there), and I noticed it ran 10C cooler. Right now, I have it up to 14x175 (2450Mhz) @1.70v, and it runs smoothly with no crashes, even with games. The temp is at 53 to 54c, so I am going to give it time to burn in (and hopefully cool down) before I try and up the settings anymore. I am using the Volcano 12 at the lowest fan settings. Would you guys try and shoot for a higher multiplier (15 perhaps) or work just on the FSB for FS2004 performance. I thing at my current temps, I am close to maxing this thing out. What do you guys think or suggest? Again, should I go for a better card?RH