[Steven-1979]

In graphics options, when a game gives you a choice like 1900x1200 30hz, 60hz, or 75hz ... which is better? I thought the higher Hz would be better but I'm getting more fps on higher hz

[EarthDog]

Do you have Vsync enabled? That should be the only reason why you would see higher frame rates with a frequency adjustment like that.

I would run it at your monitors native (LCD) or highest supported frequency for your resolution.

[sandyduff]

higher refresh rates = better.... never dip below 60Hz...

[doublejack]

This is more of a legacy setting, as it has much more impact on CRT's.

In a Cathode Ray Tube monitor, the electron beam is responsible for both the image and the illumination. You can see the lines when you look at a CRT in a camera. That line is the electron beam, scanning across the screen. Constantly drawing and redrawing the image.

In a Liquid Crystal Display, we have a backlight that provides constant illumination. A fluorescent backlight operates at ~200hz. Some newer monitors use LED backlights. The LCD shutters control the colors and brightness, and only change when told to. Either way, there is absolutely no detectable flicker on LCD's because every line of the on screen image is constantly rendered simultaneously.

The Refresh rate determines how many times your graphics card sends the image to the monitor per second. 60Hz means the image is updated 60 times per second.

In a CRT, this can affect the CRT's flicker. Flicker is when your monitor transitions from color to black or black to color. If your CRT monitor is drawing the screen faster (higher refresh rate) you get less flicker. (it still exists at any resolution, but you don't notice it above a certain point, and that point varies from person to person based on their vision)

The refresh rate on a LCD just controls how many times a second the LCD's pixels adjust. The more important measure is response time. Response time is how fast that image updates. IE how much time it takes the pixels to actually make the change.


Most LCD monitors are 60Hz at their native resolutions. You can find higher refresh rates on more expensive models, such as the Sharp Aquos or Sony models, but again, response time is more important.


At 60hz the monitor draws a new image every 16.6ms If you have an 8ms response time LCD panel, you basically spend half the time on screen changing the picture, and the other half on the image itself.

With a 2ms response time, you spend 2ms of the time updating and have the image stable for 14ms.

My advice is select 60Hz if you are using an LCD, unless you know your panel supports a higher refresh rate. Frames per second beyond 60 are mostly irrelevant when it comes to LCD's, as the extra frames just get discarded.

Setting VSync forces the GPU to only render the number of frames which the monitor can display, but this is an extra load on the GPU. Sometimes the results are better. Other times, it can lower fps and cause timing issues such as aiming for targets that have already moved or collision detection errors.

[Steven-1979]

Great info. My monitor is 60Hz / 2ms native. I'll just stick to the 60Hz. I was just wondering why switching from 60 to 75 gave me more fps. I do have vsynch enabled.

[EarthDog]

Originally Posted by Steven-1979

Great info. My monitor is 60Hz / 2ms native. I'll just stick to the 60Hz. I was just wondering why switching from 60 to 75 gave me more fps. I do have vsynch enabled.

Thats exactly why....You card tries to match the frequency of the monitor. If it can do it, it will 'lock' to that frequency. If it cannot, it will lower to 60Hz.

[Steven-1979]

But if vsynch is enabled, shouldn't both the 60hz and 75hz settings have the same fps?

[EarthDog]

Nope. When Vsync is enabled, your graphics card will attempt to match its FPS with the refresh rate of the monitor. Higher refresh rate, higher FPS if the card can handle that FPS. It prevents screen tearing so you match up each cycle of the screen with one frame.

[Steven-1979]

ahhhh makes sense! I thought it was trying to match fps to the native refresh rate (ie- never changes) ... so bumping up the refresh to 75hz makes the graphics card pump out more fps trying to match the higher Hz. that clears it up for me.

[BackBreaker]

what exactly is vsync?

[EarthDog]

Read post #8 BackB....

[BackBreaker]

so do most people have it enabled? Is that good?

[EarthDog]

If you see tearing on the screen and have a decent video card enable it. Otherwise, dont worry about it.