Hello,
I just purchased this monitor and have read through the guide on this website. Great info, I have been playing around with the settings and have been getting pretty nice results. My monitor came loaded with V3 firmware.
However, I notice when I use the VT 1350 trick, even though my custom resolution used a refresh rate of 120 Hz, the monitor reports a refresh rate of 60 Hz in the information section of the OSD. Is this normal or have I messed up the settings somehow? When I use a default resolution at any refresh rate, it reports the refresh rate that I have set. Both times I have had Blur reduction enabled, and I did not adjust any other settings.
Thanks for any info.
Question about xl2411z and VT1350
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Falkentyne
- Posts: 2805
- Joined: 26 Mar 2014, 07:23
Re: Question about xl2411z and VT1350
Yes it's fully normal.
Read this article.
http://display-corner.epfl.ch/index.php/BenQ_XL2411Z
Out of specification timings usually cause the monitor to change to the 60hz backlight pulse widths, and that's what the OSD reports.
You can go up to a VT 1500 without problems at most refresh rates (except 60hz which is VT 1260 or 1360 (I forgot). VT 1502 is the absolute maximum but sometimes (on 2720Z) it may cause random issues with suttery cursor/strobing.
I found 1502 VT works "sometimes' on my XL2720Z at 120hz and sometimes causes faint pulsing and stuttering, while VT 1500 is fine. VT1502 never works at 84hz (stutters/pulses always) but VT 1500 works fine. VT 1502 is fine at 100hz on mine.
Forgot to add:
Besides VT tweaks lowering the 2D image quality somewhat (accelerated scanout, which both VT tweaks and Lightboost 2D do, can cause a faint scanlines effect to appear around the top of the screen, particularly around greys)--and I highly suspect THAT is why the Benq monitors do NOT do accelerated scanout in hardware by default!), VT tweaks also make the "GROM" feature useless. The scaler becomes confused by the strange timings and will let you do stuff ur not supposed to do, like use an "Aspect" ratio for 1920x1080, the panel emulation screen sizes won't size properly, and smart scaling won't work. (GPU scaling DOES work, though). If you're running DX9 games and intend to use lower resolution custom resolutions (for 5:4 or 4:3 scaled or 1:1 screen sizes), you don't want to use a VT tweak, unless you're using GPU scaling to scale 1920x1080 downward (those will work just fine).
Read this article.
http://display-corner.epfl.ch/index.php/BenQ_XL2411Z
Out of specification timings usually cause the monitor to change to the 60hz backlight pulse widths, and that's what the OSD reports.
You can go up to a VT 1500 without problems at most refresh rates (except 60hz which is VT 1260 or 1360 (I forgot). VT 1502 is the absolute maximum but sometimes (on 2720Z) it may cause random issues with suttery cursor/strobing.
I found 1502 VT works "sometimes' on my XL2720Z at 120hz and sometimes causes faint pulsing and stuttering, while VT 1500 is fine. VT1502 never works at 84hz (stutters/pulses always) but VT 1500 works fine. VT 1502 is fine at 100hz on mine.
Forgot to add:
Besides VT tweaks lowering the 2D image quality somewhat (accelerated scanout, which both VT tweaks and Lightboost 2D do, can cause a faint scanlines effect to appear around the top of the screen, particularly around greys)--and I highly suspect THAT is why the Benq monitors do NOT do accelerated scanout in hardware by default!), VT tweaks also make the "GROM" feature useless. The scaler becomes confused by the strange timings and will let you do stuff ur not supposed to do, like use an "Aspect" ratio for 1920x1080, the panel emulation screen sizes won't size properly, and smart scaling won't work. (GPU scaling DOES work, though). If you're running DX9 games and intend to use lower resolution custom resolutions (for 5:4 or 4:3 scaled or 1:1 screen sizes), you don't want to use a VT tweak, unless you're using GPU scaling to scale 1920x1080 downward (those will work just fine).
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yerbamate
- Posts: 2
- Joined: 05 Jan 2015, 23:51
Re: Question about xl2411z and VT1350
Thanks for the info, I'm still new to these higher refresh rate monitors. A couple more questions if you don't mind.
Correct me if I'm wrong as my understanding on this topic is new and limited, but if the backlight is strobing at 60 Hz wouldn't the effective refresh rate still be 60Hz? Despite the fact the the LCD remains refreshing at 120Hz, it is only "lighting up" 60 times a second so wouldn't you still only see 60 Hz?
Again, please correct me if I'm wrong, and I hope I am, because I like the VT tweak but I also would like to use a true 120 or 144 Hz.
Also, that link you posted mentioned that non-standard or overclocked timings can accelerate wear on the LEDs if the average current is too high. Does this occur with the VT 1350 settings suggested on this site?
Thanks again for the replies, the info here is really helpful.
Correct me if I'm wrong as my understanding on this topic is new and limited, but if the backlight is strobing at 60 Hz wouldn't the effective refresh rate still be 60Hz? Despite the fact the the LCD remains refreshing at 120Hz, it is only "lighting up" 60 times a second so wouldn't you still only see 60 Hz?
Again, please correct me if I'm wrong, and I hope I am, because I like the VT tweak but I also would like to use a true 120 or 144 Hz.
Also, that link you posted mentioned that non-standard or overclocked timings can accelerate wear on the LEDs if the average current is too high. Does this occur with the VT 1350 settings suggested on this site?
Thanks again for the replies, the info here is really helpful.
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Falkentyne
- Posts: 2805
- Joined: 26 Mar 2014, 07:23
Re: Question about xl2411z and VT1350
No, haha.
That's sorta like like saying "if you're getting motion blur at 144 hz vs no motion blur at 60 hz, then you'll get less input lag at 60hz than at 144 hz.
Backlight strobing has NOTHING to do with screen refreshes. when you are running at 60hz, your screen refreshes (updates the position of objects on the screen by doing a full refresh) at 16 milliseconds (1/60th of a second) ,meaning 60 refreshes per second, if my math is correct. That is completely irrelevant to backlight strobing.
On a flicker free backlight, at 60hz, the backlight remains CONSTANT And on and never flickers once. The screen updates update the position of objects from the videocard to the screen, which is different from a backlight strobe.
Backlight strobing, which is what ur confusing with refresh rate, is EXACTLY the same as CRT strobing in a way. It blanks the backlight so that when objects change position, you don't see the objects in TWO positions at once (THIS is what motion blur is--its having the pixel in motion in two different positions at the same time (E.g. sample and hold).
backlight pulse widths, which is what you are thinking of, has to do with how often the backlight pulses occur. It does not have to do with the refresh rate.
you can see at 60 hz refresh rate or at 60hz pulses: http://display-corner.epfl.ch/index.php/BenQ_XL2411Z at strobe duty 001, the persistence is 0.167milliseconds --very dark screen but very clear motion! (yes I know it says 0.17, but that's rounded up. If you multiple 0.167 x 30 (strobe duty ranges from 1 to 30), you get 5 ms exactly (5.01). 0.17 x 30 is a bit higher.
That being said, if you use 60hz refresh rate and single strobe and strobe duty 006 (WITHOUT a VT tweak, although at 60hz it won't matter besides improving bottom zone crosstalk, but VT tweaks still mess up "Display mode" scaling), that's 1 ms persistence.
If you are at 100hz refresh rate and a VT 1500 tweak, that's STILL 1 ms persistence at strobe duty 006, because the 60hz pulse widths are used with VT tweaks active. However 100hz with 60hz pulse widths does not flicker. But 60hz with 60hz pulse widths DOES flicker. (a lot). You're going to need chief, strobemaster or toastyx to explain why...I think it has to do with the backlight flickering less often at a lower refresh rate, even though the persistence values are the same at 60hz without a VT tweak and 100hz WITH a VT tweak.
(edit)
I'm guessing that persistence is based on how many times the backlight strobes during a refresh rate cycle.
Lets say that 60 hz refresh rate, you get video card screen updates (and monitor refreshes of objectives moving around) every 1/60th of a second, so 60 updates a second. At a certain "X" persistence--and I do NOT know what this persistence value is...but we'll say, 60 backlight PULSE FLICKERS a second, the backlight in this hypothetical situation is flickering at 16 milliseconds (16/1000th) persistence. This is 1 backlight blank per refresh update, and that's not going to give you ANY motion blur improvement at all. That's just going to give you a migrane, lol.
Now if the backlight flashes off and on TEN times per every monitor refresh cycle, then 10 backlight strobes per refresh, meaning now, you have the backlight turns off and on *600 times* in one second. So the screen is going to be dimmer, but the ability to blank between pixel updates is going to be faster, so you're going to get motion blur reduction.
I don't know what the persistence value of 10 backlight pulses in 1 refresh cycle (@ 60hz refresh rate=600 strobes) is, but 600 strobes in 1 second is probably going to flicker. but lets move on to a better example.
100hz refresh rate: 100 refreshes in a second instead of 60 (Chief please correct me here!). Now, if you are strobing the backlight at the SAME PERSISTENCE as you were at 60hz, which is TEN strobes per refresh cycle in the original example, you now have 1000 strobes (backlight on/off pulses) in a second. You are STILL strobing at the same RATE---10 backlight pulses per refresh cycle, BUT ur strobing FASTER because the refresh rate is higher, even though it is synched to the refresh rate. I Hope this makes some sense.
Chief ?
That's sorta like like saying "if you're getting motion blur at 144 hz vs no motion blur at 60 hz, then you'll get less input lag at 60hz than at 144 hz.
Backlight strobing has NOTHING to do with screen refreshes. when you are running at 60hz, your screen refreshes (updates the position of objects on the screen by doing a full refresh) at 16 milliseconds (1/60th of a second) ,meaning 60 refreshes per second, if my math is correct. That is completely irrelevant to backlight strobing.
On a flicker free backlight, at 60hz, the backlight remains CONSTANT And on and never flickers once. The screen updates update the position of objects from the videocard to the screen, which is different from a backlight strobe.
Backlight strobing, which is what ur confusing with refresh rate, is EXACTLY the same as CRT strobing in a way. It blanks the backlight so that when objects change position, you don't see the objects in TWO positions at once (THIS is what motion blur is--its having the pixel in motion in two different positions at the same time (E.g. sample and hold).
backlight pulse widths, which is what you are thinking of, has to do with how often the backlight pulses occur. It does not have to do with the refresh rate.
you can see at 60 hz refresh rate or at 60hz pulses: http://display-corner.epfl.ch/index.php/BenQ_XL2411Z at strobe duty 001, the persistence is 0.167milliseconds --very dark screen but very clear motion! (yes I know it says 0.17, but that's rounded up. If you multiple 0.167 x 30 (strobe duty ranges from 1 to 30), you get 5 ms exactly (5.01). 0.17 x 30 is a bit higher.
That being said, if you use 60hz refresh rate and single strobe and strobe duty 006 (WITHOUT a VT tweak, although at 60hz it won't matter besides improving bottom zone crosstalk, but VT tweaks still mess up "Display mode" scaling), that's 1 ms persistence.
If you are at 100hz refresh rate and a VT 1500 tweak, that's STILL 1 ms persistence at strobe duty 006, because the 60hz pulse widths are used with VT tweaks active. However 100hz with 60hz pulse widths does not flicker. But 60hz with 60hz pulse widths DOES flicker. (a lot). You're going to need chief, strobemaster or toastyx to explain why...I think it has to do with the backlight flickering less often at a lower refresh rate, even though the persistence values are the same at 60hz without a VT tweak and 100hz WITH a VT tweak.
(edit)
I'm guessing that persistence is based on how many times the backlight strobes during a refresh rate cycle.
Lets say that 60 hz refresh rate, you get video card screen updates (and monitor refreshes of objectives moving around) every 1/60th of a second, so 60 updates a second. At a certain "X" persistence--and I do NOT know what this persistence value is...but we'll say, 60 backlight PULSE FLICKERS a second, the backlight in this hypothetical situation is flickering at 16 milliseconds (16/1000th) persistence. This is 1 backlight blank per refresh update, and that's not going to give you ANY motion blur improvement at all. That's just going to give you a migrane, lol.
Now if the backlight flashes off and on TEN times per every monitor refresh cycle, then 10 backlight strobes per refresh, meaning now, you have the backlight turns off and on *600 times* in one second. So the screen is going to be dimmer, but the ability to blank between pixel updates is going to be faster, so you're going to get motion blur reduction.
I don't know what the persistence value of 10 backlight pulses in 1 refresh cycle (@ 60hz refresh rate=600 strobes) is, but 600 strobes in 1 second is probably going to flicker. but lets move on to a better example.
100hz refresh rate: 100 refreshes in a second instead of 60 (Chief please correct me here!). Now, if you are strobing the backlight at the SAME PERSISTENCE as you were at 60hz, which is TEN strobes per refresh cycle in the original example, you now have 1000 strobes (backlight on/off pulses) in a second. You are STILL strobing at the same RATE---10 backlight pulses per refresh cycle, BUT ur strobing FASTER because the refresh rate is higher, even though it is synched to the refresh rate. I Hope this makes some sense.
Chief ?