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GSYNC vs CRT input lag?

Posted: 28 Feb 2014, 05:57
by baskinghobo
I was wondering which has less input lag? CRT of GSYNC? Also if CRT does have less input lag will the GSYNC input lag be noticable compared to the CRT input lag?

Re: GSYNC vs CRT input lag?

Posted: 28 Feb 2014, 06:12
by Haste
Hello baskinghobo and welcome to the forums.
baskinghobo wrote:I was wondering which has less input lag? CRT of GSYNC? Also if CRT does have less input lag will the GSYNC input lag be noticable compared to the CRT input lag?
As far as I know, every LCD monitors out there should have more imput lag than a CRT.


Now, about G-Sync:
With VSYNC OFF averages of 72ms and 74ms, this is very similar to G-SYNC averages of 77ms and 74ms respectively. The variability of the averages appears to fall well below the noise floor of the high variability of Battlefield 4, so Blur Busters considers the differences in averages statistically insignificant. During game play, we were unable to feel the input lag difference between VSYNC OFF versus G-SYNC. This is good news; G-SYNC noticeably improved Battlefield 4 visual gameplay fluidity with no input lag compromise.
Image
from BlurBuster: http://www.blurbusters.com/gsync/preview2/

Re: GSYNC vs CRT input lag?

Posted: 28 Feb 2014, 18:18
by sharknice
baskinghobo wrote:I was wondering which has less input lag? CRT of GSYNC? Also if CRT does have less input lag will the GSYNC input lag be noticable compared to the CRT input lag?
I thought I saw Mark post the only added input lag from the VG248QE over a CRT is the pixel transition time.

Re: GSYNC vs CRT input lag?

Posted: 28 Feb 2014, 19:56
by Chief Blur Buster
baskinghobo wrote:I was wondering which has less input lag? CRT of GSYNC? Also if CRT does have less input lag will the GSYNC input lag be noticable compared to the CRT input lag?
The latency differential between a modern (ASUS/BENQ) TN 120Hz LCD and a CRT is only about 1-2 milliseconds, when running in the best mode. This is mostly attributable to pixel transition time.

prad.de confirms this too.
(From http://www.prad.de/new/monitore/test/20 ... sverhalten then translated using http://translate.google.com)
Latency

The latency is an important value for players, we determined as the sum of the signal delay time and half the middle picture change time. The VG248QE shows generally a very short signal delay: at 60 Hz, there are still 1.6 milliseconds at 120 Hz and then 1.2 at 144 Hz even only 0.7.

Also half the average image change time is 2.3 or 1.8 and 1.6 milliseconds by the bank extremely short, thus is fantastic overall latencies yield from 2.3 to 3.9 milliseconds. Even for the most demanding gamers, this is pretty much the ultimate.
(That said, they did not test GSYNC).

Re: GSYNC vs CRT input lag?

Posted: 01 Mar 2014, 01:43
by Haste
Chief Blur Buster wrote:The latency differential between a modern (ASUS/BENQ) TN 120Hz LCD and a CRT is only about 1-2 milliseconds
How do you calculate that?

Re: GSYNC vs CRT input lag?

Posted: 03 Mar 2014, 23:35
by Chief Blur Buster
Haste wrote:
Chief Blur Buster wrote:The latency differential between a modern (ASUS/BENQ) TN 120Hz LCD and a CRT is only about 1-2 milliseconds
How do you calculate that?
The time between the signal going into the input, versus the pixels triggering a photodiode sensor connected to an oscilloscope.

Re: GSYNC vs CRT input lag?

Posted: 06 Mar 2014, 11:43
by Chief Blur Buster
Also, I forgot to also mention that there's a 1-2ms differential between VGA and DVI.

Re: GSYNC vs CRT input lag?

Posted: 07 Mar 2014, 07:47
by baskinghobo
Chief Blur Buster wrote:Also, I forgot to also mention that there's a 1-2ms differential between VGA and DVI.
Ok thanks. My monitor also supports displayport. Would that have even lower input lag than dvi or the same?

Re: GSYNC vs CRT input lag?

Posted: 07 Mar 2014, 09:35
by RealNC
Why is DP faster? Higher pixel clock? Does that mean that we can lower input lag over DVI by tweaking the timings? (Reduced vs standard CVT, for example.)

Re: GSYNC vs CRT input lag?

Posted: 08 Mar 2014, 19:42
by ENiKS
DP limit is 4K@60Hz, which means it should be able to do 1920x1080@240Hz, therefore taking 4.2ms to upload a FullHD frame. Dual Link DVI limit is 1920x1080@144Hz, taking 7.9ms.
I'm not sure if the transmit speed is fixed or changing according to monitor refresh rate. I will try to measure actual values.