Stutters solved!

[flossy_cake]

Had terminal stutters after about 2 minutes of gameplay. Game would just start pausing for 500ms every 1000ms, complete slideshow, totally unplayable, broken etc.

Turns out running LaunchGTAIV.exe instead of clicking Play on Steam has solved it. Yeah, I mean what the hell. 2 hours of troubleshooting and that was it @_@

And you know I'm not full of crap because it says something similar the readme.txt of the .dll (the one that we shan't mention):

"Notes:
* run LaunchGTAIV.exe instead GTAIV.exe to prevent "drunk" camera"

My system specs: i5-4570 , GTX1070, Win7x64

Now dont think this will make the game totally smooth, it's still got pretty bad frame pacing being an open world DX9 cpu-limited game with all the constant streaming of assets. I'm on a gsync monitor at 144hz and even it cannot save the bad frame pacing (although it's still better than a locked 144hz or 60hz). Frame delivery that goes 21ms->16ms->18ms->26ms->15ms->15ms->15ms->21ms-18ms is not really saveable on any display at any mode.

Anyway hope this helps someone.

[Kiwi]

I'm guessing the steam overlay was actually causing the trouble or the general Bootstrapper

[chiefDRE29]

windows 7 , with service pack 1 would help.
https://support.microsoft.com/en-us/help/15090/windows-7-install-service-pack-1-sp1

directx websetup:
https://www.microsoft.com/en-US/download/details.aspx?id=35
(Windows 7, Windows Server 2003 Service Pack 1, Windows Server 2003 Service Pack 2, Windows Server 2008, Windows Vista, Windows XP Service Pack 2, Windows XP Service Pack 3)

Visuals 2005 sp1
https://www.microsoft.com/en-us/download/details.aspx?id=5638

maybe try at launch commands , (steam , game properties , launch options)
-nomemrestrict -norestrictions -availablevidmem 100 -fullscreen -refreshrate 144 -frameLimit 0 -DX9_3

example , resolution 2560x1440 (16/9):
-width 2560 -height 1440
vsync is a little messed up in latest version of the game and patch.
but you can fix it.
Go to nvidia menu , 3D settings for game GTA IV.
and enable at energy settings , "always optimal"
And VSYNC or GSYNC whatever it says , to "ON" , or "Force on"
Then in the game menu you turn Vsync OFF.

If you have Nvidia inspector program ,i prefer you set vsync or gsync in there,
then you can also set the fps limiter to 144 hz .
and check the gsync settings.
You also have -vblank to turnoff the vsync ingame.
not sure how that works out with gsync