Can someone explain refresh rates vs fps.. confused!

[ashegam]

Not sure where to start so here it goes.

So say you have a 1080p 60hz monitor, new i7 CPU and a GTX 970 and you're playing a 15 year old game, like UT 99 and it shows you're getting 120 FPS.

1.So since I have a 60hz monitor does that mean I am visually not seeing more than 60fps?

2.If I turn on V-sync it would make the game go no higher than 60 fps, right? if so why would I want to do this?

3. Will I experience any stutter or lag or whatever you call it since my monitor is 60hz but my GPU is producing 120 fps?

4. Now how would things change if I had a 144hz monitor? Would I still turn on V-sync?

5. Lastly when they say "ghosting", which I know what it looks like, what contributes to this? is it only the ms spec of the monitor and that's all? If you have a 1ms monitor you will NEVER see ghosting, true or false?

Thanks!

 

[Stuka87]

1: Correct, you see the screen actually updated at 60 times a second. If you have an FPS count that is different than the refresh with vsync off, you can get screen tearing.

2: To prevent screen tearing as the possible chance of inducing latency.

3: You wont notice any stuttering or lag, just possible you will see screen tearing. Now if you truly have 120fps locked, you should not see tearing. But if you had say 110, you would.

4: With a high refresh rate, you can then see more frame a second, and therefore less flicker and a smoother experience. Now maybe a game wont run at 144fps for you, you can still set it to some other number. For instance I play World of Tanks at 85Hz with vsync. It plays better than 60Hz, I just don't have the horse power to play at a higher refresh rate than that.

 

[beginner99]

5. Lastly when they say "ghosting", which I know what it looks like, what contributes to this? is it only the ms spec of the monitor and that's all? If you have a 1ms monitor you will NEVER see ghosting, true or false?

Thanks!

it does depend on pixel response time yes but don't put too much value into the marketing stuff put on the box. This 1 ms is usually grey to grey which is faster as say black to black.

It's better to look for actual reviews of the monitor of interest.

 

[bystander36]

@Stuka87:
If V-sync is off, and you get 60 FPS on a 60hz screen, you still get tearing. Same with 120 FPS. In fact, it can look far worse to have a locked 120 FPS on a 120hz screen, than 110 FPS, because the tear won't move much at all, making it very obvious.

 

[ashegam]

So if I were to purchase a monitor capble of 144hz, I would never have to worry about ghosting, tearing, v-sync, g-sync etc. and the only limitation would become my system (more so GPU + CPU), right?

 

[bystander36]

Not sure where to start so here it goes.

So say you have a 1080p 60hz monitor, new i7 CPU and a GTX 970 and you're playing a 15 year old game, like UT 99 and it shows you're getting 120 FPS.

1.So since I have a 60hz monitor does that mean I am visually not seeing more than 60fps?

2.If I turn on V-sync it would make the game go no higher than 60 fps, right? if so why would I want to do this?

3. Will I experience any stutter or lag or whatever you call it since my monitor is 60hz but my GPU is producing 120 fps?

4. Now how would things change if I had a 144hz monitor? Would I still turn on V-sync?

5. Lastly when they say "ghosting", which I know what it looks like, what contributes to this? is it only the ms spec of the monitor and that's all? If you have a 1ms monitor you will NEVER see ghosting, true or false?

Thanks!

1. You will have 60 updates a second, but without V-sync, you can see partial frames. Let's say you have 120 FPS, you'll likely see a small part of 1 frame, half a 2nd frame, and a small portion of a 3rd frame. The fractions of each frame add up to 1. So you may see 1/8 of frame 1, 1/2 of frame 2, and 3/8 of frame 3.

2. You are capped at your refresh rate if V-sync is on. You may want to do this to prevent tearing.

3. If you are getting 120 FPS on a 60hz monitor, you'll get tearing, but not stuttering.

4. With 144hz, your screen updates more than twice as fast, making the tearing disappear faster. With V-sync, the much faster refreshes results in less stuttering when you fail to reach your refresh rate.

5. Ghosting is contributed by several factors; pixel response times, persistence and refresh rates are the main ones I'm aware of. Low response times help a lot, but don't eliminate motion blur/ghosting. Lightboost and ULMB will cause pulsing, to reduce light burn into your eye, which also greatly reduces motion blur similar to how a higher refresh rate helps.

 

[bystander36]

So if I were to purchase a monitor capble of 144hz, I would never have to worry about ghosting, tearing, v-sync, g-sync etc. and the only limitation would become my system (more so GPU + CPU), right?

144hz reduces the need for g-sync/freesync, but does not remove their benefits. G-sync/freesync will be smoother and have no tearing. 144hz on its own does not remove motion blur, but it is reduced, but many if not most also have a ULMB mode which also reduce the blur much more.

Not that you may notice all the blur on most monitors, you will see greater detail without realizing it in ULMB mode, and the same goes a for g-sync.

 

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[imaheadcase]

Yah even a game like SKyrim, which is popular still, i have to use FPS cap software to 85Hz on my 144Hz monitor or the game messes up.

 

[bystander36]

Yah even a game like SKyrim, which is popular still, i have to use FPS cap software to 85Hz on my 144Hz monitor or the game messes up.

It's not common, but there are a few of them out there. Skyrim being one of them.

 

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[PrincessFrosty]

So say you have a 1080p 60hz monitor, new i7 CPU and a GTX 970 and you're playing a 15 year old game, like UT 99 and it shows you're getting 120 FPS.

1.So since I have a 60hz monitor does that mean I am visually not seeing more than 60fps?

2.If I turn on V-sync it would make the game go no higher than 60 fps, right? if so why would I want to do this?

3. Will I experience any stutter or lag or whatever you call it since my monitor is 60hz but my GPU is producing 120 fps?

4. Now how would things change if I had a 144hz monitor? Would I still turn on V-sync?

5. Lastly when they say "ghosting", which I know what it looks like, what contributes to this? is it only the ms spec of the monitor and that's all? If you have a 1ms monitor you will NEVER see ghosting, true or false?

Its best if you understand how monitors work. They typically refresh 1 horizontal line at a time starting at the top of the screen and working down, this process takes a finite amount of time.

If during a screen refresh the video card presents the next rendered frame before the monitor has finished refreshing the screen, the monitor will simply continue through the current refresh using the contents of the new frame. This means you get a composite refresh that is made up of multiple rendered frames that are stitched together horizontally.

If there is motion and things are changing in game then the content of one frame to the next will be different, and so when you stitch 2 frames together of different content you can see what people refer to as a tear line across the screen, or simply "tearing".

The job of V-sync is to sync up the output of frames with the refresh cycle of the monitor so each refresh of the monitor only displays one full frame, it does this by delaying a rendered frame until the monitor is about to start its next refresh, tearing is then eliminated and your frame rate is locked to 60hz (or whatever your monitors refresh rate is).

There are several drawbacks of V-sync though, if your video card cannot produce a new frame for every refresh then the prior frame is used for 2 refreshes in a row, this means a video card capable of say 50fps that cannot sync at the full 60hz will end up falling back to an average of 30fps, producing frames every other refresh (skipping one), and it will keep falling back slower and slower if your video card struggles to keep up.

The other drawback is "input lag", this is commonly used but really a misnomer, it's not lag on the input but the output, V-sync works by delaying frames and so there's always some level of lag of the frames behind the input making things like aiming with a mouse very hard. Triple buffering can help lower this latency but it's never gone completely.

All monitors of all refresh rates will get tear lines, higher refresh rates primarily give you smoother motion as long as your video card can kick out that many fps. With regards to tearing you get more tearing when your frame rate is higher, the more frames you generate per second the more tear lines you get between each frame, to make use of high refresh monitors like 144hz you ideally want at least 144fps otherwise it's basically a waste, and with 144fps you're going to see a lot more tearing than if you're at 60hz.

Some of the newer monitors come with a piece of technology called FreeSync or the Nvidia propietary version called Gsync which are technologies to alter the refresh rate of the monitor to match the frame rate, it's sort of like Vsync in hardware which eliminates the input lag side of things.

Ghosting is simply related to pixel response time, this is the time it takes in milliseconds (ms) for the pixels to change colour, if you have constant motion in a game then the pixels are having to constantly change colour and you get a ghost image left behind on the screen. Ghosting always exists but becomes very hard to see at the 4ms rates and is perceivably gone by about 2ms or 1ms displays.

 

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[PrincessFrosty]

Yep that's true, the average "input lag" at higher refresh rates decreases, I'm extremely sensitive to this kind of latency between input and output as a gamer and so never use any form of Vsync ever, even on my 120hz panel.

 

[bystander36]

All monitors of all refresh rates will get tear lines, higher refresh rates primarily give you smoother motion as long as your video card can kick out that many fps. With regards to tearing you get more tearing when your frame rate is higher, the more frames you generate per second the more tear lines you get between each frame, to make use of high refresh monitors like 144hz you ideally want at least 144fps otherwise it's basically a waste, and with 144fps you're going to see a lot more tearing than if you're at 60hz.

A couple notes here:
1) Everyone I've heard, and from person experience, will say that higher refresh rates make tearing far less noticeable. This is because the tears disappear in less than half the time.
2) As far as how much tearing you get, it is 1 tear per frame generated. 94 FPS has 94 tears.
3) You will see less tearing at 144hz than 60hz, not the other way around. You'll technically get the same number of tears, but they will be visible for less time, either by having fewer tears on the screen at a time, or having some refreshes not having tears on the higher refresh rates.

If you have a high refresh monitor, play without v-sync at both 60hz and 120hz or higher.

 

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[PrincessFrosty]

A couple notes here:
1) Everyone I've heard, and from person experience, will say that higher refresh rates make tearing far less noticeable. This is because the tears disappear in less than half the time.
2) As far as how much tearing you get, it is 1 tear per frame generated. 94 FPS has 94 tears.
3) You will see less tearing at 144hz than 60hz, not the other way around. You'll technically get the same number of tears, but they will be visible for less time, either by having fewer tears on the screen at a time, or having some refreshes not having tears on the higher refresh rates.

If you have a high refresh monitor, play without v-sync at both 60hz and 120hz or higher.

1) But the total number of tears per second is higher, whether or not you think it looks better or more noticeable depends on what type of visual stimumi you're susceptible to, people differ.

2) It's 1 tear line between 2 connected frames so N frames will tear N-1 times, and actually that's not the whole story because monitors don't spend the entire time refreshing, there is a downtime period between the refresh ending and the next starting and the frame buffer can be flipped purely by accident during this period leading to less overall tearing, the timing on this is generally slightly different for each monitor, on older CRTs it used to be a lot higher because the cathode tube had to be aimed from the bottom of the screen back to the top which took some time. With 94 fps you'll accidentally sync at least a few of those frames. But it's true to say that the relationship is linear so as the frame rate goes up so does the tearing by some closely related factor.

144hz vs 60hz at the same frame rate will see slightly less tears as there's more opportunity for a frame buffer flip during the downtime between refreshes, since there's more of them, although the difference would be minor. My point with this however is that there's no point in getting a 144hz monitor if you're going to only use 60fps, if you have a 144hz monitor if you're not running 144fps then it's basically a waste.

 

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[bystander36]

1) But the total number of tears per second is higher, whether or not you think it looks better or more noticeable depends on what type of visual stimumi you're susceptible to, people differ.

2) It's 1 tear line between 2 connected frames so N frames will tear N-1 times, and actually that's not the whole story because monitors don't spend the entire time refreshing, there is a downtime period between the refresh ending and the next starting and the frame buffer can be flipped purely by accident during this period leading to less overall tearing, the timing on this is generally slightly different for each monitor, on older CRTs it used to be a lot higher because the cathode tube had to be aimed from the bottom of the screen back to the top which took some time. With 94 fps you'll accidentally sync at least a few of those frames. But it's true to say that the relationship is linear so as the frame rate goes up so does the tearing by some closely related factor.

144hz vs 60hz at the same frame rate will see slightly less tears as there's more opportunity for a frame buffer flip during the downtime between refreshes, since there's more of them, although the difference would be minor. My point with this however is that there's no point in getting a 144hz monitor if you're going to only use 60fps, if you have a 144hz monitor if you're not running 144fps then it's basically a waste.

1) No, it is not. Your number of tears if fixed, and equal to your FPS. Your hz plays no role in the number of tears you get.

2) Yes, there is a small period of time where there is no updating, but that period is quite small, and the total time doesn't change much if at all between different refresh rates. If it is a fix percentage, it will be the same no matter the refresh rate. If it is a fix time, then the higher refresh rate will have twice as much time not updating, reducing the tears, but it's small, and makes the math much more time consuming, so I generally ignore it in the comparisons. It won't make the 60hz look better either way.

120hz (easier to do math on 120hz) vs 60hz at the same refresh rate will show half as much tearing. Here are examples of why:

If both are getting 60 FPS:
120hz monitor will have a tear every other refresh, so it is shown half as often.
60hz monitor has a tear almost every refresh.

If both are getting 120 FPS:
120hz monitor will show a tear on almost every refresh.
60hz monitor will show 2 tears on almost every refresh.

In the first case, you see the tear half as long, and in the 2nd, you see half as many tears. In either case, the problem is halved. 144hz is even better.

You might also note that each tear line is removed in half the time regardless of how many tears you are getting. Each one is removed twice as fast at 120hz. This may also play a significant role in how noticeable they are. I can tell you with personal experience that going back to 60hz makes tearing painfully clear.

 

[CP5670]

You don't want to let UE1 games like the original UT run at much higher than 85fps. If you aren't using V-Sync, then they need to be capped. That engine doesn't tolerate high framerates well. Certain effects will begin to malfunction at frametares around 120fps, and game speed is also tied to framerate, so the game will actually speed up at excessive framerates.

I've seen this in Unreal and UT as well, but Deus Ex doesn't seem have any issue with 120fps as long as vsync is on. Maybe there is some difference with the UTGLR versions?

For Gamebryo, there are no-stutter mods that seem to improve behavior at high framerates. I played Fallout 3 before the mod was out and just got used to the speedup at high framerates, but played New Vegas with the mod and don't recall it being that bad.