Well on a TFT everything but the native resolution looks blurred. Also Battlefield 3 is running fine on that resolution with 45-50fps on High (no HBAO).

Well if this is to be expected than I will wait a few more month till the next investment into my hardware to play this game.

Try 1280x800 (any 16:10, if your monitor is 16:10); that's a 3:2 reduction, and it shouldn't be badly blurred. Other than that, yes, 20-25 fps sounds about right for a mid-range card (the 5750 is about the equal of the "recommended" HD 4850, but well below the GTX 260) trying to drive a high-end display.

The graphics demands of this game are not really comparable to any other, except maybe Metro 2033. Rigs that can run Skyrim or Battlefield 3 may still have trouble with this one.

Do you have UberSampling turned on? If so turn that off.

What do you have Texture Memory Size set to? If it's set to Very Large then it might be too high. Try Medium and then High if Medium runs fine.

Do you have any of the Depth of Field options turned on (Depth of Field - Gameplay, Depth of Field - Cutscenes and Cinematic Depth of Field)? What about Anti-aliasing or Vertical Sync? Maybe try turning those off.

A last resort you can try is turning up the Texture Downscaling option. It defaults to Off, but maybe try turning it up to Low. It will make the textures look worse, but it might help with the FPS.

As I said the automatic capability detection set everything to the lowest possible setting. Even though I don't consider 1GB VRAM low.
Texture Memory Size is set to Very small; Texture Downscaling is set to High. Ubersampling, AA, SSAO are all off.

Well the only other thing I can think of is to make sure you defrag your hard drive if it hasn't been done in a long time. Maybe try an older video driver, but I'm not really an AMD person when it comes to their video cards (my last AMD card was a Radeon X800 XT from 2004).

Besides that all I can really think to try is lowering the resolution. 1920x1200 sounds too high for a game like this on the 5750 (I really don't know how you'd get 45-50FPS on Battlefield 3 with High Settings at 1920x1200 with this card). I would try 1680x1050 or 1440x900 resolution if possible.

I find that when performance isn't good despite everything should be working fine, it's usually something really innocuous, that has you slapping yourself in the face afterward. So on that note, when your computer starts on the startup motherboard logo screens, does it say something like, "Press so-so to unlock cores", or "start core unlocker" or something like that? Or does it say something like, "Awesome CPU! 4 cores active!", with the number 4 promptly presented to you?

If it's the first, you need to press that key and unlock your cores first, otherwise you're running only one core. Yes, I know Windows device manager says all cores are there and working fine; but that's just a really basic "I'm here"-handshake, but that's it, they're just sitting their idle, not doing any processing until you tell your motherboard to unlock them with that keypress during startup.

It's not only about the amount of VRAM, but also the bandwith, which is pretty low on the 5750. This really affects the resolution you can play at in this game, because it's really bandwith hungry. At 1280x720 my fps is very high, while on 1680x1050 I get fps in the high twenties at times (HD5850, Q6600@3Ghz).
Your card has about half the bandwith compared to my card (128bit VS 256bit at more ore less the same mhz), so it's not that odd that your fps is low @1920x1080. It's odd that it detects all low setting though, your system is capable enough.

Does it run ok at lower resolutions? If not, something else might be wrong.

Most suggestions here mention a lower resolution. I think I will in the end go with that for now. I really can't wait for a hardware upgrade.

I obtained 20-25 FPS by following advices reported [url=http:// www.neogaf.com/forum/showthread.php?t=430456]here[/url]. I have an Ati Radeon 4650.