Looking for smoothness - benchmarking

[eLPuSHeR]

Hello.

I have been doing some benchmarking with VSYNC off. It didn't serve any purpose on my i7 because I was getting an almost consistent 120FPS

Anyway the main reason for testing that is trying to attain the best smoothness by enabling/disabling Write combining (USWC) on the graphics card. That is, switching on/off the weak ordered write cache for the graphic card framebuffer.

To do this on Vista and above, you can use a small tool I asked Wagnard (the guy who also makes DDU) to compile for me.

Wagnard's DisableVideoUSWC

The usage is simple: To DISABLE USWC just hit the "Add key" button and restart.
To put it back at defaults (USWC on), hit the "Remove key" and restart.

Some people claim they don't notice any difference at all. Keep in mind that by disabling burst access to the framebuffer you will suffer a small performance hit but with it disabled everything runs smoother and maybe with less latency (have to check on this because I am pretty sure the USWC hierarchical cache must add some latency somewhere, not sure though).

So the bottom line for me is that FASTER isn't always BETTER. With USWC on I cannot bear the screen tearing by running with VSYNC off. With USWC off it much more bearable.

Happy testing!

[Dr.Disaster]

Why again are you running with Vsync off?
Does USWC actually has an impact with Vsync on or Triple Buffer on?

[eLPuSHeR]

Howdy Mr. Disaster

I was trying VSYNC off for a while trying to get some benchmark results.

USWC off seems to make things running smoother for me. I wonder if running video output via bus bursts (using a weak ordered hierachical cache can have it downsides too [cache misses?]; also increased latency because you have to wait for buffer to be full until it gets sent to the bus).The faster a FPS is the more difference I notice. BUT, as I have said earlier, some people are unable to notice any differences. For me it's like night and day (playing any fps shooter is where i notice it the most).

Did you try it? Some unbiased feedback would be cool.

[Dr.Disaster]

Just tried it ..

For me it makes the tearing seen with Vsync off even worse. It's like increasing the number of tearing steps from few large ones to many small ones. It's also rather easy to notice, even in LoG: just strafe along a line of trees or pillars.

I prefer the tearing free going with Vsync and Triple Buffer On.

[eLPuSHeR]

OK.

Thank you for testing. That's why they say "Your mileage may vary". Every PC is a world apart.

Best regards.

PS - How about VSYNC On + TB + USWC Off? Did you try that?

USWC test wasn't meant for vsync alone; but rather for testing overall smoothness. And yes, disabling USWC WILL MAKE VIDEO OUTPUT SLOWER.

[Dr.Disaster]

PS - How about VSYNC On + TB + USWC Off? Did you try that?

Yes, tried that too. No difference at all.

[eLPuSHeR]

For me it's USWC off. I have just tried again with it ON and I got pretty dizzy when playing L4D2.