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Discussion Starter · #1 ·
Summary of input lag testing on the Vizio SV472XVT (the one with internet apps):

1. VGA 1080p - min 54ms (3 frames), average 69ms (4 frames).

2. HDMI 1080p all advanced image processing options OFF - min 61ms (3.5-ish frames), average 67ms (4 frames).

3. HDMI 1080p all advanced image processing options ON and maxed out - min 59ms (3.5 frames), average 65ms (4 frames).

Conclusion: The Vizio SV472XVT has 3-4 frames of input lag when using a HD input, and interestingly the advanced image processing features (smooth motion, noise reduction, etc, etc) don't seem to affect this *at all*, so you can just adjust for the best picture quality and not worry about sacrificing image quality to get lower input lag.


I should also note that when I first got the Vizio I didn't have the component cable for the Wii (allowing 480p) and was using the regular composite cable instead (480i). On 480i the input lag was very high. Trying to play New Super Mario Bros. Wii on 480i was frustrating and almost unplayable. As soon as I got a component cable and switched to 480p it was like night and day, and felt like I was playing back on my CRT TV. From this I'm going to assume that the Vizio has the same input lag (3-4 frames) using the component cable although I wasn't able to test this to be 100% sure. I *can* say for sure that gaming on the 472 using the composite connection is a joke and should be avoided at all costs, even with all the 472's advanced options turned off. If you have an old gaming console that doesn't have any way to output 480p or better and you want to use it with the 472 you'd need to get an upscaler so that it could convert the signal to at least 480p before sending the signal to the 472.


Pictures of these tests can be found at a flickr album I set up: http://www.flickr.com/photos/4827176...7623463745583/


Testing setup: I tested the 472 against a Sony Wega KV-27FV16 CRT TV as the 0-lag control, hooked up via S-Video, with the screens in clone/mirror mode. The video card pushing both screens was an ATI 4850, and I tested switching primary and secondary inputs on the video card using two spare computer LCDs to verify that there was no input lag issues between the primary and secondary inputs on the video card. The 472 was always running in its native 1080p. I had originally done some tests using the FlatpanelsHD flash-based lag tester, but switched to the much more accurate SMTT after doing some more reading in these forums. Using SMTT, for each picture taken there were multiple sets of numbers on the screens, so to reduce or eliminate screen refresh issues I took the highest readable number from each screen and calculated the difference. The VGA and HDMI-all-options-ON tests were done with 14 samples. The HDMI-all-options-OFF test was done with 12 samples.


I'm new to HDTVs and input lag. I see people shooting for 0-2 frames of lag on their TVs, and I was hoping the 472 would match that, but it looks like I'm not that lucky. Is 3-4 frames decent given the SV472XVT's feature set? Is there any 46-47" HDTV out there that has comparable features (LED LCD with full compartmentalized backlight, not edge backlight, wireless internet capability, etc) but better input lag? I'm a pretty heavy gamer so I'm curious if there's something out there that might be a better overall TV for me. I really like all the features on the 472, and the 472's input lag doesn't feel bad when I'm gaming on it in 480p or better (I can't really notice much of a difference compared with the Sony CRT), but I wonder if maybe the input lag is having a real affect on my gaming even though I don't consciously notice it?
 

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Quote:
Originally Posted by ninjapowered /forum/post/18281085


Testing setup: I tested the 472 against a Sony Wega KV-27FV16 CRT TV as the 0-lag control, hooked up via S-Video, with the screens in clone/mirror mode. The video card pushing both screens was an ATI 4850, and I tested switching primary and secondary inputs on the video card using two spare computer LCDs to verify that there was no input lag issues between the primary and secondary inputs on the video card.

Nice work. A few thoughts on your setup:


- You can't see all of the rows of numbers, so you could be missing the highest value on one or both of the screens.


- Using a standard-def TV as a reference is a bit iffy; the video card has to scale whatever resolution you are using down to 480i for the TV output, which may delay it somewhat from the main DVI/VGA output. Scaling like this is usually pretty fast, though, so it's not likely to be much of a delay.


- The SMTT refresh rate is about 600fps. You need at least 1000 to get full +-1ms resolution. I'd guess you're getting about +-3ms, which seems about right for the variation between your measurements. It probably averages out, but it makes it hard for me to determine if there's a delay between DVI/TV ports.


- It's possible that it's the scaling for the TV output that is limiting SMTT's framerate to 600. The 4850 is a pretty beefy card, so I'd expect a lot more than that under normal circumstances. My 8600GT managed 1100-2900, depending on the resolution and outputs being used.


Despite these variables, I'm betting that your test is pretty accurate.
 

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One other thought: did you try setting the input label to "PC" or "Game"? On some sets, this causes some processing changes that affect lag to happen automatically.
 

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Discussion Starter · #4 ·

Quote:
Originally Posted by wondras /forum/post/18299293


Nice work. A few thoughts on your setup:


- You can't see all of the rows of numbers, so you could be missing the highest value on one or both of the screens.


- Using a standard-def TV as a reference is a bit iffy; the video card has to scale whatever resolution you are using down to 480i for the TV output, which may delay it somewhat from the main DVI/VGA output. Scaling like this is usually pretty fast, though, so it's not likely to be much of a delay.


- The SMTT refresh rate is about 600fps. You need at least 1000 to get full +-1ms resolution. I'd guess you're getting about +-3ms, which seems about right for the variation between your measurements. It probably averages out, but it makes it hard for me to determine if there's a delay between DVI/TV ports.


- It's possible that it's the scaling for the TV output that is limiting SMTT's framerate to 600. The 4850 is a pretty beefy card, so I'd expect a lot more than that under normal circumstances. My 8600GT managed 1100-2900, depending on the resolution and outputs being used.


Despite these variables, I'm betting that your test is pretty accurate.

Thanks for the comments!


- I tested the CRT TV against both a laptop monitor and a fast computer LCD, and both times the CRT TV was about 10ms faster, so I'm reasonably confident that the lag introduced due to scaling down to 480i is pretty negligible. I'm sure there's some error being introduced but I don't think it would be enough to throw off the final 3-4-frames-of-lag result.


- Your comment on the 600fps got me curious and I just played around with my system settings. Turns out that AA, AF, and other image enhancing functions were on forced-on mode. If I turn them all off I get almost 5400fps. Doh! Next time I do some testing I'll make sure I get it over 1000fps during the test.


- I took the pictures before I understood how you were supposed to use SMTT. I thought you were supposed to compare row-to-row and then average the results, so since I could only see three rows on the CRT I positioned the camera to maximize the numbers' size in the picture, which cut off the 4th row from the Vizio. I went back and recalculated based on the highest number I could see even though I knew the highest number on the Vizio could have been cut off, and amazingly enough it didn't affect the results by more than 1 ms.


I think it's unlikely that a perfect setup would change the ultimate results from 3-4 frames of lag, but at some point I'll go back and retest it properly with more numbers on the screen and using the full height of both screens, 1000+fps, and a known-lag 2nd monitor that can also do 1080p.
 

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Discussion Starter · #5 ·

Quote:
Originally Posted by wondras /forum/post/18299387


One other thought: did you try setting the input label to "PC" or "Game"? On some sets, this causes some processing changes that affect lag to happen automatically.

My VGA input is labeled PC. I didn't try Game though. I'll give that a shot next time I test.
 

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ninjapowered, I am considering this TV (well actually the non internet version), and will be gaming with both a PS3 (HDMI), and a Wii (component). Do you find that the 3-4 frames lag is noticable? Did you find one with better input lag? I believe the new Sharp Qautro has really good input lag, but just viewing this site appears to have pretty bad clouding on screen sizes 46 - 60 which is what I'm looking at.
 
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