Interesting information about e-IPS panels...

[jaguarskx]

Apparently most e-IPS panel models are not 8-bit panels, but in fact are 6-bit + A-FRC panels; just like all TN panels. A-FRC means Advanced Frame Rate Control or simply temporal dithering. This probably explains why monitors with this type of panel are pretty inexpensive and can compete with more expensive TN panel monitors.

From TFTCentral: http://www.tftcentral.co.uk/news_archive/23.htm#colour_depths

e-IPS - These new panels have been in production for some time, with modules available in 21.5, 22, 23 and 24" sizes and widely used in modern popular displays. Originally the information available about all these modules suggested that they were true 8-bit displays, supporting 16.7m colours. This was in keeping with traditional S-IPS panels as well. LG.Display's website only lists basic information summaries against their panels, and in fact nowadays doesn't even give the full part number. While the e-IPS modules are not listed here any more, they were originally listed as "8-bit" in the brief description and so reviews of models using these panels will refer to them as 8-bit displays. We too fell into that trap based on the information available at the time. However, recently we have been able to study the detailed LG.Display product datasheets which describe the inner workings of the panels for OEM's looking to use them. We discovered that some of the e-IPS panels are in fact using 6-bit colour depth, with Advanced Frame Rate Control (A-FRC) to produce the 16.7m colours, similar to how TN Film panels operate. This doesn't apply to all the e-IPS panels as you can see from the table below. I would expect this was a cost saving measure and at the end of the day, most regular users would never know or care.

Here's a chart of current e-IPS panel models:

It appears the very popular Dell U2311h is in fact "a mere 6-bit panel monitor". I suppose that is why I've read some people experiencing dithering issues with the U2311h from time to time.

 

[rofl_my_waffle]

The NEC EA231WMi is confirmed to be 6-bit + AFRC (the same panel Dell is using)

Dithering isn't that noticable, most noticable when displaying what is suppose to be smooth gradients.
Its also noticable in night scenes in video games where multiple slightly different grey levels are being used.

I never owned a U2311H but I recommended it to people thinking it was 8-bit. I feel ashamed now.

 

[jaguarskx]

Actually, according to ToastyX from Hardforum, he compared both the NEC EA231WMi and the U2311H and he noticed a difference between the two monitors that is significant enough to indicate the panels are possibly different.

TFTCentral stated both monitors use the same e-IPS panel, but that was way back when LG Display provided very superficial info about e-IPS panels. And it was assumed that LG was only producing one type of 23" e-IPS panel.