IBM T221 - the world's finest monitor?

LCD MONITORS HAVE advanced in resolution rapidly over the past few years - from 15-inch 1024x768 (aka XGA) models to 20-inch 1600x1200 (UXGA) displays, which are about to enter the PC mainstream now - Samsung was also peddling 24-inch 1920x1200 (HDTV-type UXGA-W) models. At this point they match and overtake the best CRT displays in resolution and picture quality, yet with much lower power consumption, less space occupied, no radiation - and better looks!

There was one "mystery" LCD display around for some time, however, which was way above anything we could imagine - the IBM T221. A 22.2" inch wide (16:10) LCD monitor with 9.2 million pixels arranged in stunning 3840x2400 (QUXGA-W) resolution, contrast ratio of 400:1, brightness of 235 cd/m2, and viewing angle beyond 85 deg in all directions. While not known about widely (another example of top technology not marketed well before), this fantastic piece of technology can be seen in establishment involved in high-performance computing and visualisation, life sciences, hi-res imaging and satellite processig, engineering, architecture and broadcasting - you can see four HDTV channels or two 4 megapixel camera pics next to each other in full resolution with room to spare still... well, this is the highest-resolution, finest-dot-pitch monitor in the world.

I hijacked this marvel in Singapore for ten days to torture it under all possible configurations using my high-end home PC, rather than using the default IBM workstation configuration. Since its resolution and bandwidth far outstrip the standard DVI and VGA interfaces, I was curious how the highest-end 3-D workstation graphics card, the Nvidia Quadro4 900XGL 128 MB, handles the T221 advanced resolution.

Installation
The monitor comes in a compact (but still bit thick for a LCD) 543 x 437 x 196 mm (with base stand, about 2 inch thick LCD case) black IBM casing weighing 11.4 kg with base stand, plus another 1.3 kg for external power adaptor. It is a no-frills design with only four front buttons for power, brightness and simple menu management. The thing consumes a hefty 150 watts peak, quite on a par with many CRT monitors.

The back side is more interesting - besides the power and USB (for firmware flashing only) port, there are two high-density custom connectors - each connects to two DVI cables for a maximum of four DVI connections. Why so many? Because DVI supports only up to 1920x1200 resolution at the 60Hz refresh, one-quarter of T221. So, in order to get the 3840x2400 native resolution, you'd need, according to IBM, at least two DVI connections from a single card at once (to get just 21 Hz refresh by the way) or four to get 41Hz refresh.

Experience
I connected the monitor to the reference system - the 3.06 GHz Pentium 4 with 512 MB PC1066 RDRAM, WinXP Pro and Nvidia Quadro4 900XGL 128 MB reference 3-D card with two DVI connectors. Nvidia Quadro4 900 or 980 or QuadroFX are right now the recommended cards for T221. However, first I couldn't get the resolution required, as my graphics card BIOS was too old supposedly - I could only go to 3840x1200. So I borrowed a Quadro4 980XGL from IBM, and the driver installed fine. However, it would not be easy to setup for a rookie - if you want to use two DVI connectors, the graphics card treats that as two separate screens and you have to span them as one contiguous screen.

So I tried something else - disconnected one DVI cable, and tried to push the resolution all the way to 3840x2400 with single cable only (it is unsupported) - it worked! The picture was stunning - true photo quality (see the screenshots) and very precise CAD or 3-D visualisation renders with even the smallest features clearly visible - but at 12Hz refresh only. Now on a LCD even a 12Hz refresh picture was rock solid as this is not line refresh like on CRT, but of course real-time 3-D animations were a bit jerky. On the other hand, getting functional real-time 3-D at such a fantastic resolution was a great achievement by itself.

Now I tried the two-DVI configuration. When spanned as two 1920x2400 screens joined into one, the refresh rate upped to 21 Hz, however - once I started doing real-time 3-D with rapid movements (navigating through my 3-D city models, for instance), the renderings kind of split apart since the movement on one half didn't properly sync with the movement on the other, so a building would be cut in half, for instance. So, I may have as well have kept the single-DVI 12 Hz refresh mode, good enough for non-3D tasks, and no frame-tearing for 3-D tasks either. However, the new QuadroFX 2000 from Nvidia will solve the frame-tearing over dual DVI by genlock use.

Anyway, I needed to uplift the Windows desktop font resolution to 144 dpi to be able to see the characters - the looks of fonts were great, but again the physical resolution of this monitor is 204 dpi, with photo display better than what you would have from a 600 dpi colour laser printer (each dot on LCD can be any of 16 million colours while laser printers forms each true colour dot out of a matrix of primary colour dots), and all that at a display size larger than A3 format.

Conclusion
Overall, it was a whole new viewing experience - PDF files were print-quality when viewed, photos looked better than on the photographs, and 3-D models looked too real. I even had eight Internet sites open at once without overlapping. Only a few games with OpenGL, like Quake3 Arena support the full resolution though.

This monitor surely makes sense for anyone in professions like CAD/CAM, 3-D visualisation, imaging, DTP, science or even medicine. However, it is too early to look at it for the mainstream - it still needs a lot of effort to set it up even on the highest end graphics hardware, and we'd need an interface six times faster than the current DVI to get fast-refresh display at full resolution of this incredible device. Finally, it does cost a lot - something like $8,400 IBM Web price. But not to worry, some consolation - 20-inch 1600x1200 LCD monitors are now rapidly dropping in price down to the high-end home levels: watch out for some interesting entries on our pages soon... µ