LCD Refresh Rate?

[stabbs]

Good question. Still don't have a perfect answer. I have read some things on other blogs where games seem to give them more visual frames per second at the higher 75 hz than the 60hz. But I don't know what they see, because I have four different lcd monitors, and refreshing wise, I don't see any difference. I can tell very easily on a CRT monitor the difference between 60 hz and 75, and even a little between 75hz and 85 hz. But with lcd, I don't see any difference on all four of my monitors. I have three different brands that I work with every day, an NEC 90GX2 (1280x1024 res, 60hz-75hz), an Asus 241H (1920 x 1200 res, 60hz), and an Acer B223w (1680 x 1050 res, 59-60hz). I use them all simultaneously from one computer. I'm a programmer, so I'm staring at my screens all day, and I also like to game. I haven't ever noticed any jitter or glare. They all seem to work great. One isn't as bright as the other two, but it is much brighter than the CRT I used to have.

I can't test them in 75hz, perhaps due to the reason you stated. I can test my NEC in 75hz, but I don't see any difference when I do so. I tried moving windows around and doing other stuff to see if I could see any jitter or anything, but I don't. So maybe I just don't know what to look for, or maybe there are LCD monitors that actually do make a difference. Couldn't say.

Do you have a friend or anyone you know that has a 22' monitor with 60hz that you can look at and see if you can tell a difference? Maybe that's what you should do. If you do that, please respond and let the rest of us know what you find.

Anyway, hope what I've written helps. Sorry that I don't have any definite answers. Let me know what more you learn.

Thanks.

 

[stabbs]

I just read erik_tilton post (the post right before yours, jj_mclure) and it appears that maybe there could be a different if you were using analog cables instead of DVI. I don't know that I've ever tried using analog and doing 75hz. But maybe it's always displaying at 60hz, even when I switch to 75, because I am using DVI. Never tried doing 75 hz with an analog cable. Can't test that right now though, so I'll have to get back with you when I do.

-------Continued below----

Okay, so I decided to try the analog cable thing right now anyway, and I looked for a difference between the 60hz and 75hz. Still can't tell a difference. I then had my brother see if he could tell a difference, because he has a much better eye for telling a difference when it comes to stuff like this (don't know what it is with his eyes, but they are apparently very very sensitive). Anyway, he couldn't see a difference either. So, perhaps it's just that 19" monitor that you have. I'd be interested to look at it myself if I could.

Anyway, good luck in your ventures to upgrade to new lcd monitors. I hope that if you do buy that 22" monitor, that it doesn't disappoint you. Let me know if it does though.

 

[jj_mclure]

ok thanks ya'll. i'm seriously going to buy a 22" inch. i can't stand 19" anymore. it's too small being widescreen and all. regardless whether it stays 60hz or not. i'll post on here what I think of it. i'm now convinced that 60hz can't be any different than 75hz on the eyes. LCD s just don't flicker. period. thanks for your help

 

[stabbs]

No problem. But before you buy that 22", how much are you planning on spending on it, and what it's make and model is? Because I could possibly find a less expensive one, larger size, just as good of quality monitor. I manage all the purchases of hardware where I work, and so I see lots of deals and lots of different websites to buy them from, and I know the ones that are most trustworthy and those that you want to avoid.

 

[jj_mclure]

thanks stabbs, i see one on newegg.com it's an acer x223wbd.

http://www.newegg.com/Product/Product.aspx?Item=N82E16824009145

because i'm just a poor country boy. i can't afford much more.

 

[stabbs]

I understand that. I too am a poor country boy. Grew up there, got married, now live in the city, but it's only a city of 17,000. Wish I were still in the country though.

Anyway, looks like you too are a great online shopper. That's my most favorite site to purchase from. In general, they seem to have the best prices, and they seem so reliable. Anyway, that monitor appears to be a good one. I have the Acer B223W. It's almost the same as the one you are looking at. It works well. Nice find. Go for it. Great monitor for that price. Can't beat $139 for that quality.

 

[cjl]

Actually, LCDs can flicker, but for a completely different reason than CRTs. It is also independent of the refresh rate. The flicker that can happen is called temporal dithering, which is used when a lower quality (6 bit) panel is trying to simulate higher (8 bit) quality. 6 bit panels are limited in the shades that they can reproduce, but in some cases, they will try to use what is called dithering to reproduce shades that are between two of the colors that they are capable of doing. Some monitors will use spatial dithering, where some of the pixels will be slightly lighter than the desired shade, and some will be slightly darker, giving the overall appearance of the correct shade. Other monitors use temporal dithering though, where the pixels switch back and forth between a slightly lighter and slightly darker shade very quickly, and this can cause a slight flickering effect that is irritating to some people.

 

[jj_mclure]

lets hope the 6bit panels are used on no name cheapo monitors.

thanks cjl

 

[cjl]

Pretty much all TN panels are 6 bit. Not all 6 bit panels use temporal dithering though, and not all temporal dithering bothers people. This is good, because TN panels are in >90% of monitors below $400. There are a couple of exceptions, but they are quite rare. One of them is the Dell Ultrasharp 2209WA. It uses an 8 bit E-IPS panel. More expensive monitors pretty much all use 8 bit panels - as far as I know, all Apple monitors are 8 bit, the HP LP2475W is an 8 bit, the Dell Ultrasharp 2408 and larger are all 8 bit, and pretty much any higher end monitor is 8 bit (especially those aimed towards photo/video use, due to their more accurate color).

 

[stabbs]

Here's something I found from another site:

----------------------------------

http://compreviews.about.com/od/multimedia/a/LCDColor.htm

"How to Tell if an LCD is 8-Bit or 6-Bit

This is the biggest problem for individuals who are looking at purchasing an LCD monitor. Most manufacturers do not list the color depth of their display. Even fewer will list the actual per-color depth. If the manufacturer lists the color as 16.7 million colors, it should be assumed that the display is 8-bit per-color. If the colors are listed as being 16.2 million or 16 million, consumers should assume that it uses a 6-bit per-color depth. If no color depths is listed, it should be assumed that monitors of 12ms or faster will be 6-bit and the 20ms and slower panels are 8-bit."

--------------------------

jj_mclure, I looked at the specs on newegg about that monitor you want to get, and it says it has 16.7 million colors. So according to the above article, that one would be 8-bit.

As for my NEC monitor, it says "more than 16 million" so it would appear to be a 6-bit. however, I see no flicker. My Asus monitor says 16.7 mil colors though, and my acer monitor says "16.7 million (6Bit + HiFRC)". However, I see no flicker on any of them, so it looks like they have perfected any flickering problems with most monitors.

I have noticed a flicker once when I was using VGA instead of DVI on one of my monitors. It was caused when the VGA cable was near other cables and power sources. The power was making interference through my vga cable, making it flicker a little. When I switched to the DVI, with is digital instead of analog, there was no longer any interference being picked up and it worked great. However, I had a CRT monitor too, that if I turned the Hurtz up to 85, then it would get less interference than when it was at 75. So I would assume that if somebody had an lcd monitor cable (using vga) near lots of other cables, that at 60hz, they would get interference and so it would appear to flicker. But once they turn it up to 75hz, the flicker would go away. But that they might not have gotten any flicker if they used the DVI cable instead.

All this sounds logical, and from my experience, it seems correct, but, I don't have any outside research on it, so take it as an opinion and a possible avenue to test yourself.

 

[cjl]

Nope - the one jj_mclure is getting is a 6 bit. All TN panels are 6 bit, and you can spot a TN easily enough by the viewing angle. PVA and IPS panels spec the viewing angle as 176 degrees or more. The TN panels though are often 160 or 170 degrees. If you see a panel with a viewing angle of 160 or 170 degrees, it is basically guaranteed to be a 6 bit TN (to spot one in person, look at it from below the normal viewing location - TN panels have odd color shifts when viewed from below). As I said though, many of them have advanced to the point where the flickering is unnoticeable (even though it is still there).

 

[stabbs]

Very interesting. I guess that means all of mine are 6-bit, except my NEC at home which is 178 V x 178 H viewing angle. But, I literally cannot tell any difference between the picture quality or flicker of my home one and my work LCD. So, I guess that even though the flicker is there, you really cannot see it at all. So that's good to know.

Thanks for the info cjl. That is very good info. Information that I had never come across or even thought of as being the case. It doesn't sound like LED TVs will have this problem. It's cool to see new technology come in. I can't wait till they start making LED monitors.

 

[jj_mclure]

hello, i got my acer x223wbd 22" and set it up. wow, they have really improved these LCDs since my acer AL1917 of 2006. now, the resolution at 1680x1050@60hz is the max and I can notice a little difference at 60hz. but the great thing about this monitor is it scales very nicely and at 75hz on lower rez's.

1440x900@75hz looks great in games. i don't know about graphic or text though. in the big scheme I need a 22" to see because 19" was starting to hurt my eyes. it's too small. i ran the AL1917 at 1440x900@75hz native. nice monitor.

this monitor at 1680X1050@60hz is really not that bad. it's just something i will live with until the 120mhz models come out and come down in price which will be forever.

if you are looking for a 22" i recommend this one wholeheartily. i paid 139 bucks at newegg and now it is back up to 159.

i forget, but I believe in my searches that I could not find a 22" LCD that does 75HZ at any price. and, I can run 75 hz at lower rez's even using a DVI connection.

i guess 60hz is a mute point for me now.