# What is the difference between Refresh Rate and Response time?

#### hassan.kassir002

##### Prominent

The most frustrating thing is if the whole world agreed to a definition of something that your brain refuse to understand.

Every single website said that response time is the time it takes for color of pixel to change, but It is not enough definition for me.

The reason i am having trouble is because i learned the definition of refresh rate years before i discovered response time, and i am confusing between the two, here's why:

Refresh Rate, such as 60hz, means the monitors can display 60 framesa second, and each frame is different from the other, so the colors of pixels change in every frame, which means the monitors can change colors of pixels 60 times. In other words, 60 refresh rate means colors are changing 60 times a second and each time is equal to the other, so response time of 60hz is 1000ms divide by 60, which is 16.66, which means colors change every 16.66ms. So refresh rate tells you how many times colors of pixels change in one second, and response time tells you the time it takes to change color of pixels one time only. I am lost.

1) it is just hardware capability of the monitor

2) 5ms is fine

3) response time is the time it takes to change color of pixels

None of the above has helped me, it just made it worse

#### punkncat

##### Respectable
Well, the easiest way I know to explain, and this isn't really apples to apples...

Refresh rate is a similar description of what people call frame rate. A monitor running refresh rate of 60hz will "match up" to 60 frames, etc.

Response time is the amount of "lag" between screen change commands, so to speak. The lower the response time the less lag to that change. Gamers want as low a response time as possible so as not to have control lag.

There is more to it and you can go way deep in tech talk about it, but that is about as simple as I know to try and describe it.

#### hassan.kassir002

##### Prominent
I wanna ask one more thing, imagine a 1hz monitor with 900ms response time (Obviously it doesn't, but imagine it does exist for the sake of the question)...

One frame has been sent to the monitor, 900ms of lag is gonna happen, our brains are capable of observing 900ms visually.... What would we see during every 900ms lag?, would we see black, white? What would we see during transformations of colors?

#### Glenwing

##### Honorable

Pixels aren't changing all the time. They spend a few moments changing (when a new frame is drawn), then spend the majority of the frame period staying on the same color. The response time is the part of the frame period that is spent actually changing color, not counting the rest of the time.

Refresh rate is the number of frames per second. At 60 Hz, each frame is on the screen for 16.66 ms. So when a new frame commences, the pixels may spend 1 ms changing (response time), and then stay on that color for the remaining 15.67 ms of the frame.

#### Eximo

##### Titan
Herald
Glenwing pretty much has it, but it doesn't take 1ms to change all the time, or 4ms, etc. Usually far less. I'll explain below.

GtG gray to gray is often the most common figure cited. That is basically the time it takes to go from a designated color and reach another shade of gray. They pick these to suit the result they want. Black to White response time is more indicative of overall performance, but is usually not provided.

But to get into the annoying fact that there is no standard for response time measurements, and manufacturers can pick and choose test parameters to get the best results. Take anything you see from marketing material with skepticism. Best to look at independent reviews on any monitor you are looking at purchasing.

Pixels are essentially light gates in LCDs with the backlight shining through. So if your pixel has to go from one shade of red to another it will be a lot faster than the provided response time since the adjustment is smaller. So more time is spent with the pixel on the right color.

Ghosting is an effect of residual output even after power is taken away/provided from/to the LCD. The most common way to combat this is to strobe the backlight in time with the refresh rate. Less light output through the pixel, but ghosting is minimized.

You can get into extreme detail on the construction of LCD pixels, but response times aren't all that useful. Just know that your typical TN panel is going to be faster than VA and IPS/PLS and that VA is typically inbetween. Most of your high refresh rate "IPS" displays are VA.

Twisted Nematic
In plane switching
Vertical Alignment

Plasma and OLED panels operate fundamentally different as each pixel IS the light source, rather than having a backlight. It is why they have deeper blacks and usually very good response times. Here's hoping they can solve burn-in and longevity issues.