what did you do to make battlefield run better? i'm about to download and test that game soon.. also, my computer hasn't shut down, but that's probably because of overheating? idk.. i've only played games for about 5-10 minutes because i was testing the stuttering and fps issues.

The computer shut down when my power supply cut and I played GTA IV or DR2 for a while, but not when my cord was plugged in.  For Battlefield, I downloaded the driver 275. (something something, refer to earlier pages).  And also did Krillin's tweaks in the lenovo power management.  Battlefield became smooth alongside GTA IV's temporary lag-free gameplay.

Almost all of the new games I play are choppy when plugged in.When I plug out, I can play without a problem.I`ve read the older thread, but their solution does not work for me.Is there ever gonna be a fix for that, I didn`t want a gamers laptop on which I cant play games...

Well, it's not such a terrible problem.  Right now at the moment, the only games I have trouble with are GTA IV, Bioshock 2, and Dead Rising 2.  Bioshock 2 runs crappy at even the lowest settings which is BS because the y570 completely exceeds the recommended requirements for the game.  Maybe its just the optimization for the ported games that makes the laptops go choppy i dunno.  Anyways GTA IV is a poorly ported game, but if you want to play games like Black Ops or Resident Evil 5, Assassin's Creed 1, 2, or Brotherhood, Mass Effect 2, Borderlands, you will be FINE as I played all of them on my computer.  I'm thinking that the sandbox games which require a lot of firepower its draining our gpus.  But by the way, if you try playing GTA IV or any of the games mentioned above when they are choppy and you unplugged your computer, the laptop will most likely overheat and turn off which is quite risky, so I recommend you play plugged in and solve using some solution thru software.

Hey guys I have read else where this may help.

For some reason when power management is set to max for plugged in it causes issues. Try changing it back to normal and it should eliminate the stutter.

By normal do you mean setting the lenovo power settings to balanced?

Yes balanced but you need to change both the lenovo power settings and windows power settings

hey shorty,I too have this problem.I cant solve it even with Kiril's option.What do u mean changing both Lenovo and windows power option.When I cnage Lenovo option from high perfomace(i thing this is what u mean max-right?) to balanced it automaticaly change the windows power option to balanced.It's not big deal but I'll try it and examinate it then i will post the results.Thanks. :) I hope lenovo fix this minor but very nasty issue becouse the model is very nice,I still love my Y570.By the way let for the sake of fixing the problem all of us write yours OS.Mine is Win 7 x64 Ultimate ;)

So overall I'm summing up the solutions that could best do to reduce the lag to some games for people who are new to this thread.

1. Generically, first make sure your Nvidia is turned on by the metal switch on the bottom left of the laptop WHEN your computer is on (Light turns on when it's on). (BTW I love the manual graphics switching other than automatic in my opinion)

2. Switch the battery options on the battery options (windows 7) to high performance and lenovo battery options (one of the icons on the taskbar) to high options as well.  Also on the Lenovo Energy Management, click on the Power Scheme (the blue cog wheel on the bottom next to the question mark and the i), go to the Smart Power Saving tab, and uncheck both.

[http://forum.lenovo.com/t5/IdeaPad-Y-and-U-series-Laptops/Y570-Games-lags-and-choppy-when-it-s-plugged-in/ta-p/502355]

*NOTICE* Sometimes when playing heavy sand-box games where your graphix card will sweat the most, some people recommend setting the lenovo settings to energy star which may show smoother but lower fps.

3. Go to the laptop2go site to download driver 275.33, the bottom link and download both the driver and the inf file and replace the inf file in the original driver folder with the separated one.

[http://www.laptopvideo2go.com/drivers/win7x64/275.33/disclaimer]

(Most of you will not be able to download the legit driver from nvidia as the common error message that the **bleep** driver can't find any compatible hardware, so we try to improve).

*NOTICE* It may be just my y570, but before I installed this 275.33 driver from laptop2go, Bioshock 2 ran fine.  Now, it seems to lag profusely, and I tried reinstalling and it is a bought game so don't question the legimitaticy.

I'm somewhat a heavy gamer and before the changes I made (except for #1 and half of #2), Battlefield Bad Company 2, Resident Evil and some other games could play from medium to high settings.  As I mentioned above, Black Ops, Resident Evil 5, Assassin's Creed 1, 2, or Brotherhood, Mass Effect 2, Borderlands, Arkham Asylum, Fallout, Starcraft 2 are all playable, with high settings.
There's been a strange occurence to me when I play heavy sand-box free-roaming games like GTA IV and Dead Rising 2, as it sometimes gets smooth (even when its plugged in) and sometimes it gets choppy.  (Crysis has some choppy problems as well, but not has heavy as the two mentioned above).  And when it's choppy I wait for a bit and it gets smooth after 5-10 minutes of choppiness.  Over-all, these three solutions are what this thread has displayed, and I'm just summing it up so people don't have to look arond all pages.
Thanks to Kirill, M47R1X, defjam.

Here is a fix go into power managment then click advanced power management and scroll down till you see processor power management.  make the min and max 90 while plugged in. And stuttering is gone.