How can I identify the actual color depth of my LCD (6-bit or 8-bit )?

I recently purchased a 22” monitor : iiyama E2202WS for around $245 from an x-mas sale. Here are some information listed in the user manual:

• Driving system : a-Si TFT Active Matrix
• Pixel Pitch: 0.277mm H x 0.277mm V
• Brightness: 300 cd/m^2 (Typical)
• Contrast Ratio: 1000:1 (Typical)
• Response time: 5ms (Black,White,Black)
• Display Colors: Approx. 16.7 million maximum
• Dot Clock: 162MHz maximum

Hardware ID listed by Windows device manager is : MONITOR\IVM5603

From what I’ve read 6-bit panels are normally advertised as having 16.2 million colors while 8-bit panels with 16.7 million. Therefore the above spec is little confusing, while it seems like an 8-bit because of 16.7 million colors; words Approximate and maximum add some ambiguity. Does the a-Si TFT means anything?

While searching I found this forum post, I can see the difference between the light blue and green squares quite clearly (looks better than on M1330 LCD).

I just want to know because earlier I was planning on ordering DELL E228WFP or Acer AL2223Wd over the internet (only 22"s I could find fitting my budget over here in Japan) , both of which are 6-bit panels. I bought the iiyama monitor from a nearby store as it was on display advertised as 24bit 16.7million color LCD (and on sale of cause). I viewed a couple of HD videos and several photos at the store, they all seemed quite alright, since I was bit hesitant to buy a monitor online without actually seeing it for real, I decided to buy that iiyama instead.

 

Actually the diff between 6-bit and 8-bit is 262,144 colors vs. 16,777,216 colors in "high-speed" mode. The text "Approx. 16.7 million maximum" and the fact that you have a TFT monitor leads me to believe you have a 6-bit monitor just like everyone else.

Also another way to tell is if you can actually see dithering between subtle colors like clouds in a sky.

I have two of those Acer monitors and yes, they are 6-bit, but they are very bright and vibrant monitors and I would recommend them to anyone.

High speed 8-bit monitors (suitable for gaming) are going to cost you as much as a 6-bit 32" TV.

 

Thanks for replying, I know the technical differences between the two. Problem is visually identifying. when looked closely I see a slight dithering effect even in some of the high quality photos, but I’m not sure whether its caused by JPEG compression or the monitor. Very hard to find uncompressed high resolution images on the web. Guess I’ll have to find a true 8-bit monitor and compare.

Any other suggestions ? tools or test images (like the one in that forum) etc. ?