Here's the scenario:
 
I purchased a new PC about 22 months ago; XP Pro, AMD4600+ X2, Asus GF7950GX2, 4GB of DDR2 800 (I believe) on an Asus board. At the time, I picked up FEAR and Oblivion in order to see how far I could push the graphics, and everything ran incredibly well. And compared to those two, World of Warcraft ran like a dream.
 
A few months ago, I began noticing that when I was in graphically intense areas of WoW, I was losing frames pretty badly - going from 55-60 to under 20 at time, spiking back up to ~60. I wasn't gaming much at the time, so I didn't pay much attention to it. Now I've picked up Age of Conan, and although I met all of the "Recommended" system specs (save for OS), I was seeing frequent drops into single-digits while monitoring my framerate. Given what I'd been seeing for the last few months, I'd started to think that perhaps my GPS was just "tired", and maybe it was time for a new card.
 
So, after reviewing prices and reading the review on the 9600GT here, I decided that it would be my most cost-effective upgrade path. I ran a 3DMark06 pre-installation and came up at ~8500 score (not great). I uninstalled my video drivers and replaced the card. I installed nVidia's latest ForceWare driver (I forget the current rev number), rebooted, and then ran 3DMark06 again to see how much improvement I'd actually gained. And...
 
I got exactly the same 3DMark score. Exactly.
 
I'm not hardware guru by any stretch of the imagination; mostly I've picked up troubleshooting tips and tricks here and there from friends who're network architects, sysadmins, etc - but most of THEM are pretty fuzzy when it comes down to the nuts and bolts of hardware, too. But it seemed ridiculous that I'd walk into WoW and see exactly the same performance I'd seen with the 7950, experience the same framerate issues in AoC even after upgrading to a card that this site thought fairly highly of (for an 'inexpensive' card).
 
As far as maintenance goes, I defrag about once a month, but am still working on my original XP install nearly two years post-purchase. The case is roomy, well-cooled and clean enough to rule out dust causing heat issues.
 
I've had a few recommendations I've yet to try; these include:
 
1. Using a video driver scrubber utility. Some posters in the AoC forums are recommending this, as it appears normal uninstall proceedures aren't entirely cleaning out old driver entries specifically with smoe nVidia cards.
 
2. Raising my settings. I've continally dumbed-down my 3D settings, filtering, etc to try to avoid the dreaded 5fps canyons, to no avail. However, some people have said that with newer graphics cards (8800's and up), they noticed significantly WORSE performance when reducing settings and gotten significantly better performance when raising the settings on things like Shaders, Antialiasing and Anisotropic Filtering. It seems counterintuitive, but could this be the case? As it is, I'm trying to run with AF and AA off entirely, with the lowest shader settings I can select.
 
3. Reformatting.
 
So, to sum up, I went form a 2-year old 7950Gx2 to a brand spanking new 9600GT and got not a lick of performance improvements. I ask the gearheads here: where would you go from here, if you were me, as far as getting to the bottom of this conundrum?

The 9600GT is only 2 steps up from the 7950GX2, so you wouldn't get that much more performance from it.
 
http://www.tomshardware.com/review [...] 923-7.html

9600gtx2

get a 8800GT or wait for the 4xxx series from ATI. return the 9600GT if u can

When I first bought my 8800GTS 512, replacing a 7900GT, Crysis ran horrible. Going from the game to the menu screen and back literally took a couple of minutes. The frame rates were also way too low. I also used driver cleaner but the game still ran horribly. Once I formatted the game ran great. You might want to think about doing that.
 

I agree the 8800GT is the card of choice right now, of course new cards will be coming soon though.  The 8800GTS 512 is also a solid option, though both are $200+ right now.  In terms of ATI, the HD 3870 is the top card, or the crazy 3870X2.  The 3870 is on par with the 8800 cards, and gets almost the exact performance as the 8800GTS 320.  Check Tom's Desktop VGA charts.  So, if you could return or sell the 9600GT, the 8800GT 512 or 8800GTS 512 are the best cards as of right now.

You replaced a $500 card (when it was new) with a $150 card.  The 9600GT performs a bit better than the 7950GX2 and the margin depends on the game.  The 7950Gx2 seems to fluctuate performance depending on what game you are playing. My buddy has one and it's like that. Depending on whether it does well with SLI or not.

You replaced a super highend card, at the time, with a lower-midrange gamer card.  The direct upgrade path from the 7950GX2 would have been the 9800GX2.  In that case your socks would have been knocked off.  Even an 8800GTS/512 or 9800GTX would have been a better selection.

I apologize if the comment came off wrong, but I think you set your sights a little to high with the 9600GT. At least from what you were upgrading from. Most people upgrading to the 9600GT are coming from an older midrange card.

I am willing to bet that it is a CPU bottleneck just like my card paired with AMD 64 4200+ x2

There's way too much 9600 GT hate.  You can OC that sucker like no one's business.  The 7950 GX2 was a good card, you can't expect that much gain.  The 8800 GT is only slightly above it, but not once an overclock is applied.

the 7950GX2 was a powerful card for its time and depending on the games is not that much faster or slower then the 9600gt.  
 
You are saving a good amount of power.  
 
Games that do not take advantage of SLI should run better on the 9600gt.
Games that do may be the same or slightly slower depending on the game.

---------------
http://tinyurl.com/26uxxb - Core2 Temp Guide
http://tinyurl.com/cj3pw - VGA power use

I agree an OC will help him our dearly.  I really like the 9600GT its an absolutely fantastic card.  I just think he was expecting way to much from it.  I went from an OCed x1900XTX to the 8800GTS/512 and noticed a difference. Not super astonomical difference, but if I went to the 9600GT it would have been 20% less.  And on certain games my x1900xtx wasted my buddies 7950GX2, and he admitted it.  So I think something a little more powerful would make the OP happier.  Maybe he can get a 2nd 9600GT and SLI it if his board allows.

jay2,
 
Yes and no. I wasn't expecting to suddenly push 70fps sustained, or anything.
 
My concern is that the performance of my 7950GX2 slipped significantly over time. That's why I expected to see more of an upgrade going to a "fresh" 9600GT.
 
My problem now is that I'm getting the same performance frmo the new 9600 as I was getting from what seemed to be a VERY underperforming 7950. I'd thought the card was the issue, but now I'm wondering if there might be software / registry / driver issues causing my problems. The fact that I saw absolutely NO performance upgrade seemed to be telling, to me. I just wasn't sure where to really start digging.
 
After all, after potentially blowing $130 on a new video card I might not have ended up needing, I don't want to go and drop another $150 on a new CPU only to have the same problem. So, I'm sorta trying to find out where the "no money down" things are that I should check before I go down that road.

As mentioned it's marginally better, but even that margin is greatly diminished by the somewhat weak CPU it rides upon.
 
You have access to more features (like FP16 HDR+AA in Oblivion, or DX10 in some new titles) but overall for games optimized for the GX2, you will get very similar performance. The nice thing is for the games that had issues with the GX2 you should see greater stability and performance.