Dirt CPU with Great GPU vs. Great CPU with Integrated Graphics?

neither... meet in the middle on both cpu and gpu.. nvm I just read the title, idk

its a compaq so its hard to know what CPU's the motherboard for it will support since pre-built computers usually locked to certain ones as rebuilt computers are not really designed to be upgrade friendly

Very true, I did not think about that

http://www.cpubenchmark.net/cpu.php?cpu=AMD+Athlon+II+170u
vs
http://www.cpubenchmark.net/cpu.php?cpu=AMD+Phenom+9500+Quad-Core

1) Both are pretty weak, but the 170u is really low-end. Arguably not even too good for Windows let alone gaming. The OS is going to already eat up much of that single core leaving very little for a game.

Probably about 4x the gaming potential with the 2nd GPU compensating for Windows usage but it's pretty hard to guess.

*And yes, knowing what CPU works is difficult. You would need to find the actual MOTHERBOARD MODEL and BIOS version, then see if you can find the "CPU Support list" or find someone who can verify that a different CPU works in that exact motherboard.

(not just compatible SOCKET, as the BIOS must have the CPU listed. If it's not the PC won't start.)

2) iGPU?
Horrible, just horrible. Stick with the 9800GT which is many times better.

3) 2GB of system memory?
you will need to pick and choose your games carefully. If you could install more memory that would be ideal though don't spend much updating, make sure it's compatible etc. In fact, Windows is probably 32-bit which is a problem.

4) Windows 32-bit?
If so it only supports 4GB of memory. That includes:
a) VIDEO, and
b) SYSTEM, and
c) (minor other stuff)

It assigns the last, and video first when booting leaving the potential (up to 4GB) left. If you had a 1GB video card you can support up to about 2.8GB.

4) GAMES:
You will need to very, very carefully choose your games and TWEAK the settings. I'm talking maybe Torchlight 1/2 if you're lucky. It's hard for me to guess. Nothing demanding. You'd need to experiment with free demos/games or whatever to try to find out where you stand.

Possibly something like Command and Conquer 3 which is still a great game with the 2nd CPU and the 9800GT.

SUMMARY:
The main difficult recommending this is I don't know what you're spending to upgrade. Maybe at most $100 for the 9800GT plus the 2nd CPU. Any more and I'd start looking for a USED system with better specs.

OTHER:
A used GAMING CONSOLE might be worth considering.

OTHER:
For non-gaming, some Linux distros can give you a much better experience for web browsing and general usage. Personally, if it was me I'd wipe the drive clean (after recovering any files) and if Linux can do what you need then install that.

https://itsfoss.com/lightweight-linux-beginners/

I'm not an expert. Not even close, though my first guess would be LUBUNTU for the present system. Some Windows programs can be made to run using WINE. Otherwise, probably FIREFOX for browsing, VLC for video (though only lower resolution video unless you have some GPU acceleration which I don't think exists, at least not for modern video usage.