Using T4x as streaming video sources: results

[raueda1]

I posted this in response to another thread, but realized that it might be of broader interest. So here it is again in the hope that it may help somebody.........

I've recently been fiddling around with the T4x <--> HDTV question. The aim is to find a reasonable "head unit" for streaming video (Hulu, Netflix, etc) to HDTV. Obviously this can't be true 1080i HD, but I want to get the best I can out of it without further enriching the cable provider (who i just cut off!! )

I've evaluated the following Thinkpads:
1. 15" 1.8 Ghz T42p UXGA, 2gb ram, Radeon 9600 and 128mb vram
2. 14" 1.7 Ghz T42 SXGA+, 1gb ram, Radeon 9600 and 64mb vram
3. 14" 1.7 Ghz T42 XGA, 2 gb ram, Radeon 7500 and 32mb vram
4. 14" T40 1.4 Ghz XGA 1gb ram, Radeon 7500 and 32mb vram

All have Bluetooth and were controlled by a Bluetooth mouse from a viewing distance of about 10' from the 51" screen. I'm using the usual dock with DVI output to feed the HDTV. The TV is a 51' rear projection CRT unit with a DVI input (apparently not a common feature), so I don't need DVI -> HDMI adaptors or any USB dongle stuff. I set up a dual displays using Presentation director. TV display resolution was set to 1280x720 with 16 bit color depth (more on that later). The dock is fed by hardwired 100mb ethernet and whatever feed I get from the cable modem. The browser was Firefox. The display was sharp enough to read everything and manipulate the system from the viewing position. It was initially a little fuzzy but I realigned the TV focus (which needed redoing anyway) and the improvement in resolution was dramatic.

The overall winner is #2. Video from #3 and #4 tended to be choppier and pixalate more in high-motion segments, such as fire, explosions, etc. These also had a hard time displaying Hulu's so-called HD (420p?) which was always unwatchably choppy.

#1 and #2 were about the same in performance. The extra ram and vram of #1 didn't seem to make any discernible difference. However, the higher resolution made setup much harder unless the laptop display resolution was downgraded to XGA; shifting between the LCD and CRT displays was much harder. For some reason the full-screen mode in Hulu and other players didn't ever seem to work right on the high-res unit. There seems to be something about the player software that can't manage high resolution display modes on the laptop. I could never get it centered right.

With unit #2 it worked immediately and is easy to use even when laptop display was running in SXGA+ mode. Hulu's HD mode was usually OK on both units. The improvement in resolution is quite obvious over their standard def. Sometimes it's choppy, which I attribute to variations in internet feed quality. Who knows? Subjectively the picture quality on Hulu HD is somewhere between "digital cable" and DVD. It's absolutely good enough for casual viewing. Old Star Trek episodes are actually the best I've ever seen. The media players on some sites still don't display right in full screen mode on the HDTV when the laptop res is set >XGA. I'll be fiddling with a few more presets in Presentation Director to switch modes more easily.

Finally, I didn't see any difference between 16 bit and 32 bit color on any of the units. I stuck with 16 bit with the notion that this would be less CPU &/or GPU &/or memory intensive. I really don't know, but it seems like it can't hurt.

I've now been using unit #2 for several weeks and it works admirably.
Make of this what you will, hope it helps and good luck in your own experiments!