Gsync Importance @ 144hz

FBPerformance · August 23, 2016

Still trying to figure out what monitor to go with for my new skylake/1080 build. My budget is no more than $800USD but obviously lower price would be appreciated. My question is, is GSync @ 144hz - 1440p really important? I could go all out and get the ROG Swift 279 model and have the best of the best. But I have a feeling I would be happy with a 144hz 1440p monitor without gsync or does it really play a big role? I will be playing mainly AAA games like FPS & RPG. Any opinions are welcome on what to buy.

bgibbz · August 23, 2016

13 minutes ago, FBPerformance said:

Still trying to figure out what monitor to go with for my new skylake/1080 build. My budget is no more than $800USD but obviously lower price would be appreciated. My question is, is GSync @ 144hz - 1440p really important? I could go all out and get the ROG Swift 279 model and have the best of the best. But I have a feeling I would be happy with a 144hz 1440p monitor without gsync or does it really play a big role? I will be playing mainly AAA games like FPS & RPG. Any opinions are welcome on what to buy.

it depends on personal preference. I for one dont think its a huge deal, but i know some people who would refuse to use a monitor that doesnt have gsync/adaptive sync on it. Whatever peoples stance on it is, its not hugely important. The display will look great regardless of whether you get a gysnc monitor or not.

Falkentyne · August 23, 2016

This day and age, you need either adaptive sync, or a strobing backlight. With adaptive sync (gsync, etc), you will get CONSISTENT framerates, meaning the frames will be smooth, but blurry, as you still have eye tracking motion blur to deal with. But if the fps drops and rises a lot, the frame transitions will of course, speed up and down, but it will be a smooth transition, rather than jerks and stutters. Without adaptive sync, you will have repeated jerks, pauses and stutters if the framerate fluctuates a lot under the set refresh rate. And if the FPS is fast enough to maintain the refresh rate in FPS, then you have to deal with vsync and/or triplebuffering so you don't get tearing from the FPS going above the refresh rate with vsync off.

But yes, if you're always getting 144 fps at 144hz at all times, there's no benefit to Gsync if the FPS is remaining consistent.

With a strobing backlight, you then have the option of using strobing to remove the eye tracking motion blur, which makes things much more clear and readable. But in order to make actual use of this, your FPS should equal (or exceed, but then you can use vsync to cap it) the refresh rate at almost all times. If the FPS drops below the refresh rate often, you lose most of the benefits of blur reduction, and the image doesn't become much better than a non gsync, non blur reduction image at low framerates.

Gsync monitors almost all come with ULMB mode (a very few do not), so if you did not get a Gsync monitor, you would also be losing blur reduction, unless you bought a Benq XL Z series screen (or XL2430T) or paid $1300 for the Eizo FS2735.

You cannot use ULMB mode and Gsync at the same time.

3d vision 2 monitors that support gsync have a firmware bug (at least the Dell version does) where it's possible to enable strobing (Lightboost) at the same time as Gsync, due to some very hard to replicate and complicated bugs. The monitor will say it's in ULMB mode but it's actually in Lightboost mode, and strobing at variable refresh rates. It's really nice to see it in action, but this almost impossible to replicate (literally involves making the driver or game crash).

Benq blur reduction is more adjustable and brighter than ULMB mode, because backlight voltage is increased by ~1.8x for strobing (a common complaint about ULMB mode is this lack of compensation), and you can adjust the pulse widths to absurdly low values (like 0.069ms at 144hz, or 0.167ms with a Vertical Total tweak active) and up to 5.0ms (with a VT Tweak), as well as reduce strobe crosstalk (only by using VT tweaks). The XL2730Z freesync monitor has far fewer adjustments (crosstalk reduction no longer responds to VT tweaks, so crosstalk is rather high, and it won't strobe lower than 120hz and at custom refresh rates), but still maintains the brightness advantage. On the pre-XL2730Z monitors, you may have to exploit some firmware bugs/toggle settings to reduce the excessive overdrive down to reasonable levels.

FBPerformance · August 23, 2016

1 hour ago, Falkentyne said:

This day and age, you need either adaptive sync, or a strobing backlight. With adaptive sync (gsync, etc), you will get CONSISTENT framerates, meaning the frames will be smooth, but blurry, as you still have eye tracking motion blur to deal with. But if the fps drops and rises a lot, the frame transitions will of course, speed up and down, but it will be a smooth transition, rather than jerks and stutters. Without adaptive sync, you will have repeated jerks, pauses and stutters if the framerate fluctuates a lot under the set refresh rate. And if the FPS is fast enough to maintain the refresh rate in FPS, then you have to deal with vsync and/or triplebuffering so you don't get tearing from the FPS going above the refresh rate with vsync off.

But yes, if you're always getting 144 fps at 144hz at all times, there's no benefit to Gsync if the FPS is remaining consistent.

With a strobing backlight, you then have the option of using strobing to remove the eye tracking motion blur, which makes things much more clear and readable. But in order to make actual use of this, your FPS should equal (or exceed, but then you can use vsync to cap it) the refresh rate at almost all times. If the FPS drops below the refresh rate often, you lose most of the benefits of blur reduction, and the image doesn't become much better than a non gsync, non blur reduction image at low framerates.

Gsync monitors almost all come with ULMB mode (a very few do not), so if you did not get a Gsync monitor, you would also be losing blur reduction, unless you bought a Benq XL Z series screen (or XL2430T) or paid $1300 for the Eizo FS2735.

You cannot use ULMB mode and Gsync at the same time.

3d vision 2 monitors that support gsync have a firmware bug (at least the Dell version does) where it's possible to enable strobing (Lightboost) at the same time as Gsync, due to some very hard to replicate and complicated bugs. The monitor will say it's in ULMB mode but it's actually in Lightboost mode, and strobing at variable refresh rates. It's really nice to see it in action, but this almost impossible to replicate (literally involves making the driver or game crash).

Benq blur reduction is more adjustable and brighter than ULMB mode, because backlight voltage is increased by ~1.8x for strobing (a common complaint about ULMB mode is this lack of compensation), and you can adjust the pulse widths to absurdly low values (like 0.069ms at 144hz, or 0.167ms with a Vertical Total tweak active) and up to 5.0ms (with a VT Tweak), as well as reduce strobe crosstalk (only by using VT tweaks). The XL2730Z freesync monitor has far fewer adjustments (crosstalk reduction no longer responds to VT tweaks, so crosstalk is rather high, and it won't strobe lower than 120hz and at custom refresh rates), but still maintains the brightness advantage. On the pre-XL2730Z monitors, you may have to exploit some firmware bugs/toggle settings to reduce the excessive overdrive down to reasonable levels.

Thanks for the excellent description ! Do you have a opinion on what monitor would be best? Currently looking at the asus rob swift pg279q as an IPS monitor is important to me as well.

Falkentyne · August 23, 2016

I only have a Benq XL2720Z so I play with blur reduction (strobing) on at all times, and at a refresh rate low enough so the FPS stays equal to the refresh rate.

I can't tell you what to do because I was an old CRT diehard holdout.