I've had this card since about halfway to late last year, if I remember correctly, and it was all fine and dandy.
It was pretty much the expected jump of performance from the GTS 450 that I had before it.
It's been running at a moderate overclock, just enough to get a little extra performance out of it.
 
Anyway, recently it's been showing this weird phenomenon that it struggles with games that it didn't struggle with before.
Such as even Source Engine games, which it should have no problem with at all. But even with say 'Team Fortress 2' and about 20 players shooting around, the framerate would drop into the 40s (at the busiest moments), while before it would stay at 60+. And heck, I even got an average framerate of about 40 back when I still had a Pentium 4 with an AGP-card in 2008. And the GTS 450 didn't have much trouble to stick to an average of about 50fps either with a medium-high mix setting in that game. What gives?...
 
I don't know what changed. I've even had like half a year of playing few games at all, perhaps updated the drivers 2 or 3 times (including some failures),
 and the recent few months it's been delivering pretty shoddy performance.
 
Also, it's a behavior that is all too familiar. Because when I still had the GTS 450, it would have "expected" performance at first, but then after some time of usage, particularly when updating to newer drivers, the performance would just decrease. - I suspect that since the drivers are shared with many different GPUs, the priority gets shifted towards the newer cards, and the older cards are considered on their way out and get the shaft.
If that's the case, are there any specific drivers that would deliver the best performance for the 750 Ti?... This was the case with the GTS 450, but I had to figure it out for myself, because I was like the rare person using it and no help from the nVidia or EVGA forums back then.
But there was really a specific driver that would top out the performance of the card and any driver after that would just "break" it. Not sure if that's the case with this one...

Other than that; Any clue as to why this happens?...
And I'm not saying this happened because of different drivers in this case, because I don't know the exact point of when it changed. I think even before a driver-change.
But it just did... I can't even run Source-games properly (with the settings not even on full, and I play at 900p as well)... Which today is like the most basic thing.
I have to add that I turned from overclocking manually, which seems to be less effective now, to turning on "framerate target", which (as expected) maximizes performance, but it's still not up to where it was when I overclocked it manually before.
 

Do #1 & #2 listed here to see if it helps restore performance. Check your cpu, gpu & mb temps for overheating. Make sure your cpu/gpu are running at advertised speeds when gaming. Enabling frame rate target doesn't maximize your performance, enabling frame rate target will keep your fps from going over whatever fps number you have set for the target.

There is no overheating whatsoever. In fact, the GPU's fans don't even go up as it doesn't need the additional cooling, which is a known characteristic of the card.
I'm pretty sure the GPU is being underutilized. Also, when I try to peek at the graphs in monitoring-software such as Precision, it seems the GPU-utilization doesn't go very high. I'm not sure if that's just because of certain games (such as those on the Source Engine) not being thát demanding, or if GPUs just don't always max out. But it just doesn't seem to be working very hard. I would like to just fire it up, but it seems it's lazy.
I've also cleaned it out and re-seated it over time and such...
 
I actually always thought that "framerate target" would let Precision "auto-configure" the card so that it would get as close to that number as possible. But I guess I misunderstood that. - In any case, sometimes there's no framerate to limit, as it often doesn't even reach the 60fps that I set it to aim for. And if it does, it would just cap off at 60 anyway, because in games that can afford it (such as, again, Source Engine games) I will definitely use V-sync. The problem is just, it often won't reach framerates that it should be able to. (And, of course I'm not talking CryEngines maxed out or anything.)
 
For now, I'll try to use the steps on the other page and I'll see what happens.
Drivers have definitely been an issue, because while the first few times went OK, it would fail later updates.
I would get it to install one way or another, and also the most recent update went quick and flawlessly. Inconsistencies all over the place.
Anyway, I'll try some things...

OK, I've tried the first step, which didn't seem to really matter.
 
Now I've uninstalled everything and cleaned with the tool.
But when I try to install the latest drivers (that actually came out today), just the basic graphics and PhysX drivers with "clean install" checked, I get a "runtime error".
I've included a screenshot of what that looks like.
 
I remember getting this before and it was really difficult to get drivers installed. I don't even remember how I did it. So at the moment, I can barely use my computer with this tiny resolution.
 
What is causing this error and how can I get the drivers installed?
I could have another look at the DDU-tool, which also seemed to have a driver-installer, but I'm not sure.
 
I'm not happy... I don't do any funny business with my computers and no matter how much it has been simplified, it still only works like 1 out of 5 times for me. And I'm talking ever since I had a GeForce 3. - Every new card installs and runs alright the first time. But then I try to update, which is recommended, it all just goes wrong. - Weird.
 
Now, excuse me while I scroll down to reach the "post"-button. :P
 
Update: OK, so to my surprise the drivers WOULD install in Windows Safe Mode, because usually you can barely change anything that way, but there was no option to install PhysX, so that would be an additional problem. - But even though the drivers are installed now, performance is even more inconsistent, sometimes seemingly giving higher framerates (say in the 70s) and sometimes even dropping down to the record-breaking 30s. - And I'm only talking about letting 31 bots run wild on the Nucleus-map in 'Team Fortress 2' (on only mostly high settings at 900p). So I guess I could forget about other more demanding games that I have played with this card before (I'm willing to bet that 'Tomb Raider' wouldn't even break 30fps now).
I was also monitoring the usage of the GPU and CPU, and while the CPU was only hanging around 50% utilization, the GPU was hanging around only 30%.
Is this just because that's all there's being asked for by the software, or is this just wrong?... Why is it being so tame?...

When looking at the individual cores of your cpu do you see one running close to 100%? If yes, your problem is related to the game being cpu bound/limited. To make the game more gpu bound use the nvidia dsr feature to increase your resolution, increasing your resolution with the nvidia dsr feature will definitely bring the gpu utilization up past 30%. 

No, I don't think it does. - But even if it was, it wouldn't make sense.
Why is it that when I first used the card (and I'll stick with 'Team Fortress 2' for example) it would have no problem just clamping the framerate at 60fps with V-sync on, but now it fails to do so? And fun fact; I just tried lowering the resolution to 720p, turning off things like anti-aliasing, and the performance did not become any better.
It doesn't seem to matter how light the engine is and how low the settings are, the card just doesn't want to perform (anymore).
 
But I'll try DSR and see if it fixes/forces anything.

If none of your cpu cores are close to 100% then maybe a game update, windows update, or nvidia driver is the cause of the issue. You may want to try some older graphics drivers to see if it helps fix the problem. Have you optimized your games with geforce experience? If yes, please do #5 listed here to see if it helps fix your problem.

I've checked again, and the CPU-cores run pretty evenly.
The games are up-to-date, as is Windows 7, and I just installed today's GeForce-driver. - What older version would you recommend?
 
I have never let GeForce Experience optimize game-setting because I like to set them myself.
But if I do it manually, like I said, I've even tried medium to low/off settings at 720p just now, and it still likes to dip down into the 40s or 30s.
Using DSR didn't seem to help either...
 
Currently, GeForce Experience and also PhysX-drivers are not installed.
I guess I'll go try older drivers next.

Using dsr didn't help raise your gpu utilization? Try driver 347.88.

No, it doesn't seem to make a difference.
I've now tried versions 359.06 and 347.88, and perhaps they deliver slightly better performance, but it's still pretty craptastic.
The card just likes to really tank and freak out as soon as there are more than 10 shooting characters on screen. Even with a significant overclock.
It also doesn't really seem to introduce artefacting, which before it would do at some point. It's really like it's just not running fully. The highest temperature is 41 degrees... It couldn't give me a fever.
It is giving me a headache, though...