60hz versus 120hz and high refresh rates

[OFaceSIG]

So I'm trying to wrap my head around 60hz and 120hz and refresh rates. I realize that 120hz looks much smoother in general versus 60hz but my question is where do refresh rates come into play?

Before 120Hz I always bought faster and faster refresh rate monitors. Now I have 2ms monitors, the ones in my signature.

For example if there is a 120Hz 8ms monitor does it look worse than a 60Hz 2ms monitor? Any guidance will be appreciated!

 

[Inu]

there are very few 120hz monitors above 4ms

the 4ms response time refers to something different than the refresh rate. It's somewhat technical, and i can't explain it.

Typically (probably always) 120hz is going to be better than ANY 60hz monitor.

 

[hughJ]

It's not just about smoothness, but also latency. 120hz means your screen is going to get updates every ~8ms. 60hz means ~16ms. Pixel response time gets tacked on after that.

For the whole input->output chain, assuming 60hz w/ 60fps and 2ms display response time, you've got a theoretical best case latency of 18-34ms (16 draw + 0-16 scanout + 2 pixel switch) between the time your mouse gets polled for input, and the time you see pixels fully changed on your display.

For 120hz w/ 120fps and 8ms response time, you're looking at 16-24ms (8 draw + 0-8 scanout + 8 pixel switch). So even with a much larger response time, you're getting much more immediate input along with twice the number of updates per second.

 

[Mark Rejhon]

Typically (probably always) 120hz is going to be better than ANY 60hz monitor.

Motion-blur wise, 60fps@60Hz CRT has much better motion clarity than 120fps@120Hz LCD. That said, the flicker is certainly bad.
The reason about this is also explained below, see below.

So I'm trying to wrap my head around 60hz and 120hz and refresh rates. I realize that 120hz looks much smoother in general versus 60hz but my question is where do refresh rates come into play?

Before 120Hz I always bought faster and faster refresh rate monitors. Now I have 2ms monitors, the ones in my signature.

The panel pixel response is not equivalent to motion blur; CRT's often had a phosphor decay of 1-2ms. LCD transition times have already approached that. But there's still more motion blur on LCD. The problem is LCD's are often sample-and-hold, while CRT are strobed. This is why CRT's still have clearer motion than LCD's, even though pixel persistence is now a similar time period as phosphor decay of medium-persistence CRT.

Display motion blur (at fps=Hz) is proportional to the length of time a visible refresh is displayed for.

120 Hz IPS overclock .................... 40% less motion blur than 60 Hz LCD -- (8.3ms sample and hold + streaking)
120 Hz TN panel ........................... 50% less motion blur than 60 Hz LCD -- (8.3ms sample and hold)
120 Hz LightBoost ........................ 85% less motion blur than 60 Hz LCD -- (2.4ms strobe flash)
120 Hz LightBoost(10% setting) ..... 92% less motion blur than 60 Hz LCD -- (1.4ms strobe flash)
120 Hz CRT ................................. 90% to 95% less motion blur than 60 Hz LCD -- (~1-2ms for visible phosphor decay)

Vega measured the first of 5, and I measured the last 4 of 5 -- and pcmonitors.info has vouched -
"For others reading this and wondering about those figures (vs CRT) above, they aren’t plucked from thin air. I have also done similar testing"

Refresh rate, alone, DOES NOT necessarily dictate motion blur. Nor does panel response.

The use of flicker (e.g. CRT, plasma, LightBoost stroboscopic backlight) reduces motion blur, by shortening the amount of time the frame is displayed for. This eliminates the motion blurring caused by eyes continuously tracking moving objects. (Your eyes are in a different location throughout a visible refresh; so the longer-displayed refreshes are more blurred across your vision). See science references for more info. Bigger black periods between frames (the black frame insertion effect) means less motion blur, since the stroboscopic shortening of the frames allows motion blur reduction without needing to raise Hz excessively (to GPU unmanageable territory, e.g. 240Hz or 480Hz native).

Is resolution during stationary images more important? Go 1440p IPS, etc.
Is resolution (lack of motion blur) during fast moving images more important? Go LightBoost or CRT.
Are you mainly gaming on the display?
If so, do you want only 2x improvement, or 10x improvement in motion clarity?
Only displays with short visible frame lengths such as CRT and LightBoost displays have sufficient motion blur elimination capabilties; to push motion blur below human detectability thresholds.

Also see High-Speed Video of Strobe Backlight as well as LCD Motion Artifacts 101.

 

[Geforcepat]

Man 120Hz Rocks! i refuse to run any monitor on my desktop that is not at least 120HZ its not too hard to wrap your head around

 

[der_bothaus]

It is if you value color quality. Now you actually have a quandary. Fast and crap colors or slower and perfect colors. Depends what you value as expressed by Mark in above post. All choices are a tradeoff. But I do agree if you are going cheap and TN you should at least go 120Hz. The 60Hz TN's can be laid out to pasture as IPS 60Hz can compete with them now with far better color.

 

[Mark Rejhon]

It is if you value color quality. Now you actually have a quandary. Fast and crap colors or slower and perfect colors. Depends what you value as expressed by Mark in above post. All choices are a tradeoff. But I do agree if you are going cheap and TN you should at least go 120Hz. The 60Hz TN's can be laid out to pasture as IPS 60Hz can compete with them now with far better color.

Pretty much agreed.