Dell 1905FP: capable of 75hz at 1280X1024, but why is it not optimal?

[PremiumG]

Why is 60hz optimal according to the monitor?? Will 75hz reduce ghosting at all?? Even if not, isn't 75hz better than 60???

 

[VIAN]

It was built to work at 60Hz, if you don't you are running it out of spec. Therefore, you don't get the best image quality possible. It will not reduce ghosting. 75Hz isn't better than 60Hz.

 

[Peter]

The "refresh rate" doesn't matter because LCDs don't refresh. All the pixels are statically lit or dark all the time.

Thus, the frame rate is just limiting the rate at which pixel states can _change_ - and 60 Hz (16ms) is way good enough for the _actual_ pixel change rate on today's LCDs ... if you ditch the 12- or 8-ms figure on the box and look at real life performance.

 

[ChuckHsiao]

Consider that 60 Hz means you're feeding the image data 60 times a second to the monitor. There are 1280 x 1024 x 3 = 3.93M sub-pixels. Each sub-pixel receives one byte of information a second. This means that at 60 times a second, your monitor has to take in 236 MB of information a second, or almost 2 billion 0's or 1's a second. That's not a lot of time to squeeze all that data in. However, data cables (and monitor drivers) are sufficient for that. If you bump it up to 75 Hz though, that's 295 MB of data a second, which starts to stress out the electronics. Hence you can run it at 75 Hz, but image quality will be somewhat degraded because more data has to be sent per second. How much though is a matter of personal preference, so you're welcome to try. But 60 Hz is usually sufficient, so that's the optimum rate that manufacturers design the components for.

 

[JBT]

LCD's don't need more than 60hz, as hz rate isn't quite the same as CRT's. LCD's are static images and aren't "refreshed" so thats why its optimal...

 

[jiffylube1024]

As others have said, 60Hz is fine for LCD's. First of all, it's what they're designed for. Second, LCD's are not redrawing the screen line-by-line like CRT's, so a higher refresh rate doesn't reduce flicker. As a matter of fact, LCD's shouldnt flicker at all - if you notice any bizarre flickering in the screen, it's most likely the cable (too long, low quality, etc). a short run DVI cable should produce a flawless, flicker free image at 60 Hz.

A higher refresh rate has nothing to do with ghosting (ghosting is affected by response time, which is just the speed at which the pixels can rotate for the various transitions, and depends on the panel, not the refresh rate.


So, install your LCD, hit your i key (or whatever optimize button your monitor has) and you should have a flawless corner-to-corner screen filling image.

 

[Peter]

Well, response time (which equals pixel change rate) can't be more than the frame rate fed by the host computer. Even though panels are advertized as being sub-10ms, actual response time for arbitrary (!) pixel changes are a lot higher. Hence, the 16ms interval provided by a 60 Hz frame rate is plenty enough.

 

[xtknight]

Motion blur should be *appear* more visible (really just more often) at higher refresh rates because the LCD has to try harder to keep up. I use 75 Hz, because at 60 Hz my mouse feels slow and jerky.

 

[Peter]

No. Motion blur is entirely a function of response time. Once your frame rate is anything faster than the panel's actual response time, it won't get any worse if you crank the frame rate even further up.

 

[Mygaffer]

It is funny how much completely incorrect information is in this thread. People clearly did not understand LCD technology back in 2005.

If anyone is ready this all these years later the Dell 1905fp can run at 75hz @1280x1024. That is not "out of spec" as someone else claimed.

Also as everyone has found out higher refresh rates do matter for LCD's with higher refresh rates leading to less motion blur.

Test out your monitor here:
https://www.testufo.com/#test=framerates