jDRP and Vertical Sync - Better framerates

[ravenlot]

I'm sure a lot of people already know this but I just discovered something. Turning ON Vertical Sync seems to help framerates when using the jDRP. (NOTE: Actually, I've been using an altered jDRP ... one that uses Gamedude's DED changes and my own reduced resolution skins but I expect there would be an improvement with the standard jDRP as well.)

I have a Geforce4 TI-4600 with 45.53 drivers. There are newer drivers available but they seemed to be better optimized for newer cards. I usually have vertical sync turned OFF by default because it generally gives me higher framerates in games like Counter-Strike. Anyway, I've had it OFF all this time while playing Doomsday. I had thought this was the best way to go because of its affect on other games. Even Doomsday's FPS counter displayed numbers in the hundreds. When I encountered slowdowns with the jDRP, it didn't occur to me that turning ON vertical sync would help since I knew having it ON would generally limit framerates.

Well, this morning it just happened to turn ON because I was experimenting with newer drivers. Installing the newer drivers turns it back ON be default. I had wanted to see whether the newer drivers increase performance when running Doomsday with the jDRP. I didn't expect it to do so but I wanted to try it. Performance did increase but I traced it to the switching ON of vertical sync, not the newer drivers themselves.

With vertical sync switched ON, I checked out my framerates in Doomsday. They were capped at 60fps, rather than the 300+ fps that I was getting before. BUT I was no longer getting severe slowdowns out of nowhere. Besides, I couldn't tell the difference between 60 and 300fps. I'm still getting some slowdowns but it's a lot more manageable now. Also note that this is WITHOUT tweaking the particle settings.

Another setting I tried was to change the Image Settings in the Geforce panel to High Performance. I think it helps and I didn't notice any significant changes in image quality. But it's kind of hard to tell for sure whether it helps.

Anyway, I hope that helps some people out there experiencing slowdowns.

[draconx]

What VSync does is it forces the card to wait until the monitor finishes drawing one screen before telling it to draw the next. Therefore you might notice a difference between the 60 and 300 fps - 60 will be better as its not drawing faster than your monitor can display. If the graphics card tells the monitor to draw a different image before the monitor finishes drawing the previous image, you'll get a "shearing" effect, where different frames are drawn on the same refresh.

Usually though, vsync has a performance hit...

[Doom_Gate]

Wow turning vsync off uncapped mine from 60 now i get about 260 thank you

[Tyberious]

a human eye detects approx. 24 frames per second as fluid movement, the same ratio movie theaters use to run films on reels. Anything above taht wint be notices much accept for something around 100 as being really high speed.

[draconx]

Doom_Gate - getting MORE than the capped 60 will only have a negative impact - if vsync is capping it at 60, your monitor is only drawing a screen 60 times a second. The graphics card is sending a little over 4 images per monitor refresh with your 260 fps - therefore, when the first frame is 1/4 finished rendering, the gfx card sends the next frame. The monitor *will not* continue to draw the first frame, instead it will stop drawing the first frame and start with the second. Until the third gets sent, then the fourth.

So in one monitor refresh, you will have the top quarter of your screen showing the first frame, the top-middle quarter showing the second frame, the bottom-middle quarter showing the third frame, and the bottom quarter showing the fourth frame. this causes that "shearing" effect that i mentioned.

The shearing effect can sometimes be barely noticable, but take a look at the opening of Chrono Trigger for the snes - when you see that pendulum moving back and forth very quickly across a black background - you easily see the effect (notice how it disappears with vsync on)