Question on 120 hz monitors.

[95thrifles]

There's a difference between reaction times and perception of delay. Reaction time tests measure the gap between seeing a signal, and enacting a response, but if the lag on your equipment is less than this lag time you can still perceive it as being sluggish.

Taking myself as an example, I've taken these tests before, and my reaction time is around 80-100ms in general. But still, anything over 20ms seems sluggish, and enabling vsync (on my 60Hz screen) makes the controls seem very sluggish indeed.

Well for starters youre obviously in that top 0.01 percentile that that test figures is impossible to reach, going on that test 200ms average I'll explain better where I was coming from

Whilst yes there is a difference agreed, your eye sees something on the screen, you react which takes 200ms, clicking the mouse, theres then an amount of lag from mouse input/screen image etc to take into account before your click registers, people claiming to be able to tell the difference between a 2ms and 6ms response time are claiming to be able to notice 1% difference (in addition to their reaction time) which is pretty impressive (read BS)

Yeah, by that logic having a 200ms reaction time would mean you wouldn't notice the difference between 5 and 10fps?

No, not really, the brain can process more information than it can react to thats all

 

[Duff-Man]

people claiming to be able to tell the difference between a 2ms and 6ms response time are claiming to be able to notice 1% difference (in addition to their reaction time) which is pretty impressive (read BS)

First up, remember that "response time" as quoted for monitors, is NOT the same as input lag. In fact, it isn't any kind of lag at all... Response time refers to the time it takes the pixel to cycle, and is not anything to do with input lag. A screen with a (quoted) 2ms response can still have a very high (50ms+) input lag in principle. Similarly a screen with high (12ms) response time can have a very good (sub-20ms) input lag.

Regarding the issue of human response time vs. feeling input lag... Remember that while it does take a person a fair amount of time to respond to a sudden stimulus (around 200ms average), the brain is still processing during that interval. If you're dealing with a continuous output (e.g. moving a mouse), then the mind can perceive even a very slight delay between what it expects and what it sees. In short, the mind is "back-processing" the visual stimuli it gets.

Anyway, the facts are that it's easy to quantify input lag (whether due to the monitor or due to vsync or both), and if the total lag is more than a threshold you are comfortable with then the controls will feel sluggish. This lag-threshold will vary from person to person, but will certainly be much lower than their "instantaneous response" reaction time.

 

[Dash RipRock]

I find im most sensative to mouse lag when im on the title screen of any given game and you have a cursor.Then using fast moves left and right a slightly muddy feeling and delay can usually be seen (felt),on 60 hz it`s very noticeably there in a lot of games (for some strange reason doom 3 is horrendously noticeable,dont ask me why ).

When selecting 120 hz you just become unsure if your seeing/feeling it or not and basically your probably looking so hard your convincing yourself it is there (speaking for myself of course ).The moment i go into a game for instance borderlands or COD it just feel very instant to me and any lag is so minimal as to be not worth noting.Btw Borderlands running at a solid 120fps makes you weep tears of joy at how smooth it is ).


All the above is of course with vsync ON.

 

[Duff-Man]

(for some strange reason doom 3 is horrendously noticeable,dont ask me why ).

Everything in the Doom3 game engine is tied to a 60Hz ticker - if you run at higher than 60fps you're simply re-drawing the same frame. It's kind of an odd way of working, and the only other game engine that I know of that does the same is the Oblivion engine (fallout3, fallout new vegas etc) - this engine is tied to 64Hz.

Anyway, this could have something to do with it... Perhaps Doom3 won't get quite the same benefit from a 120Hz screen?

 

[Dash RipRock]

Everything in the Doom3 game engine is tied to a 60Hz ticker - if you run at higher than 60fps you're simply re-drawing the same frame. It's kind of an odd way of working, and the only other game engine that I know of that does the same is the Oblivion engine (fallout3, fallout new vegas etc) - this engine is tied to 64Hz.

Anyway, this could have something to do with it... Perhaps Doom3 won't get quite the same benefit from a 120Hz screen?

I was gonna suggest that but couldnt be sure if it was the case.I suspect it is because there is a console command that you can use to "unlock" it`s 60 hz timing. (i think it was originally done because of exploits that people could use when running games like quake 2 at certain frame rates that enabled you to do jumps that just weren`t possible at most other frame rates.It was done as a multiplayer "fix" )

The trouble is when you unlock it everything you do runs twice as fast when you vsync to 120 .Talking of peculiar issues in games ,gta 4 has a belter.It to is a game that looks like it`s internal timing (for want of a better word) is tied to 30 hz/fps (tut...console ports eh ) but when you run it any faster than that it all seems fine....until you come to the last mission.Without spoiling it for anyone theres a section in the last part of the mission that requires you to use the old track and field style button mashing to pull yourself up from something.

The clever amongst you may have spotted what happens next......yep you guessed it the amount of presses per second was "tied" to a certain amount you could do in 30 "fps/hz".If your frame rate was 60 fps you had to do TWICE as many presses IN THE SAME amount of time ...and what do you know...at that stage in the game i was running at nearly 90 FPS....and wondering WTF i just couldn`t do it despite BATTERING the hell out of my space bar for around 10 attempts ...anyway quick work around was just before the section appeared.....start a fraps recording which brought frame rate down to 30 fps and bang....did it first time .So remember ..gta 4...last mission..you want to run at 30fps (sorry for going on but i just HAD to relay that story,off topic that it is )

 

[Duff-Man]

^^

That's a pretty big fail on the part of rockstar! Though really, given the fact that the entire game smells of "quick and dirty console port" it's not that surprising

 

[Rroff]

Several of the GTA games have similiar issues. San Andreas you'd sometimes "crater" and die horribly just walking off the edge of something fairly low and mafia 1 had a mission you couldn't complete without using the framelimiter or fraps as you get stuck in the scenery.

 

[Dash RipRock]

^^

That's a pretty big fail on the part of rockstar! Though really, given the fact that the entire game smells of "quick and dirty console port" it's not that surprising

hehe Agreed,i enjoyed it despite it`s obvious short comings but if ever a game needed another 6 months fine tuning/bug fixing to produce a better result it`s this game.And for the love of god some anti-aliasing , i can forgo AA in most games when running at 1920x1080 to keep frame rates nice and high but in GTA 4 sigh .....i know lights "shimmer" in the dark but every vertical surface and girder on a bridge???...surely not

 

[dmxdex2020]

Yes, every monitor has a different input lag. If you read a review they will usually test the input lag. Anything under 20ms is pretty good, and for most people will not lead to a feeling of "lag". If you enable vsync, then it will add a lot more lag to this (see my post above). The 120Hz screens tend to have a low input lag, but there are plenty of other screens that have low input lag too.

What screen are you using?

I have the BenQ G2420HD.

 

[dmxdex2020]

I turned all of my in game settings to off and low. In DX11 my mouse now feels extremely smooth in turning yet im getting similar fps. Why cant i play this game with high settings with a smooth mouse. It is the same with Far cry 2. I just dont understand it. Why does my mouse become a tad laggy with higher settings but with similar fps. COD MWF2 feels perfect at max settings. FEAR 2 feels fine at max settings in DX10. Left for dead 2 runs perfect also.