Sli wont work with vsync on

James1_24

Distinguished
Oct 25, 2011
8
0
18,510
i5 and 2x GTX 570 and windows 7 32bit

Im at my wits end here. I just cant get sli working on any games. Iv just recently upgraded windows, from Home Premium to Ultimate now. Iv also done a clean install of windows

For example in Deus ex HR I get 60 framerate with vsync on but with it off I get over a 100

some difference aint it

what is wrong?

Iv the latest gpu drivers btw
 

Gothams Finest

Distinguished
Sep 15, 2011
1,475
0
19,360
You are aware that vsync limts the frames per second to your monitors refresh rate, so if your monitor is 60Hz then vsync will limit your fps to 60. That is what vsync is for.

Make sure you have connected the SLI bridge correctly and you have enabled SLI in the Nvidia control panel.
 

James1_24

Distinguished
Oct 25, 2011
8
0
18,510


I wasnt ware off that

I know sli is enabled because of my score in 3D mark

Before my upgrade of windows 7 the sli was perfect, Im pretty sure I didnt need to go near the vsync within the game to get a high frame rate so that's what I cant understand the problem now
 

Gothams Finest

Distinguished
Sep 15, 2011
1,475
0
19,360
Are you getting good FPS with vsync turned off? If so then it is just vsync limiting your fps to 60.

Vsync is good to have because it reduces screen tearing and it also stops your graphics cards working any harder then is needed.
 

James1_24

Distinguished
Oct 25, 2011
8
0
18,510
yap but is there away to have the high frame rate without the screen tearing ?

Has to be tbh, what is the point of sli other wise
 

Gothams Finest

Distinguished
Sep 15, 2011
1,475
0
19,360
Yes there is a way to have the higher frame rate without screen tearing....buy a new monitor with a higher refresh rate such as 120Hz then you can have a maximum of 120 fps with vsync enabled.

If your monitor is 60hz then you can only see a maximum of 60fps... anything higher then 60 fps is wasted on a 60hz monitor.

The point of SLI is to be able to play at higher frames per second with higher settings then you could get from just using a single card.

You should be happy that you can get a constant 60fps on most games maxed out.

You don't need any more then 60fps, but if you really have to have 100+fps and vsync turned on then you need to buy a new monitor.

If you bought two 570s because you thought things would run better and look better with 100+ fps then you are mistaken. There is no benifit in having over 60fps on a 60 hz monitor.
 
^+1

Look at it this way. Your monitor updates it's screen at the rate of it's hz. In your case, 60. So no matter how many frames your computer generates, only 60 frames get updated per second.

Every refresh is accompanied by a period where nothing is updated by the monitor. This is called Vertical retrace mode. When you turn on v-sync, the graphics card will not update the frame buffer unless it's in vertical retrace mode. This prevents the frame buffer from changing while it's being written to the screen, preventing 2 different images from being displayed at once which results in what looks like a tear through the screen.

If you are able to get over 60 FPS on a 60hz monitor, it is only a good thing to use v-sync. Not only does your monitor not display more than 60 frames, but if you try, you end up with tearing on the screen.

The only reason to have more FPS than your monitors hz is for bragging rights.

As mentioned above, if you want more displayed FPS, get a 120hz monitor.
 

James1_24

Distinguished
Oct 25, 2011
8
0
18,510
thanks gothems finest and bystander for the help, its nice to know its nothing major wrong with my computer

I think it maybe time to invest in a new monitor
 


As you can see in my signature that I have a 120hz monitor, and it is very nice. Especially when turning fast, it looks a lot smoother.
 

James1_24

Distinguished
Oct 25, 2011
8
0
18,510


what is the 3D like ?
 


Awesome. I don't feel like playing any game that doesn't offer 3D vision support. You might want to look for 3D vision 2, it's supposed to brighten things up a lot, which is one of it's few drawbacks (adjusting gamma settings helps too).