how come monitors still use DB-9 connectors? i hate that bulky cable behind my computer, and having to screw down the bolts on either side. its horrible. we did away with the worst offender, parallel cables, i don't even have a parallel port on my desktop if i remember correctly. they all use USB now. i posed this question on hackadays comments section once, i don't remember which hack, but it was relevent. the only response was along the lines of "USB doesn't have the power to run a monitor. it only has 500mA max." when i pointed out that every monitor ever has a IEC jack on the back, because they are plugged into the wall as well as the computer. also, how come i've only seen one wall wart in person that has about a foot of cable for the plug after the box, so it doesn't crowd the surge protector. i've seen wall-warts so big i can't use the second outlet if i plug them into a wall. power squids are the answer to a problem that shouldn't exist! so can anybody explain these things to me?
Bandwidth, TBH. 1600*1200*(32/8)*75 res. colour depth. refresh rate. =576 Mbps USB runs at 480 max, even at lower qualities (not the way the technology's going) it'd use the full bus speed. And it's a HDD15, not a DB-9. And everything's DVI now. I'd assume the main problem is that with a serial conection, the monitor would have to have a lot of hardware on board to convert it back to a useable signal. For the power adapters, it's cheaper.
wow, i never realized they use that much bandwidth. the cable is so thick because they need a lot of shielding right? that much data going through must make some nice EMI. i sure wish they'd redesign the whole interface though, its a PITA to tighten those when your case is jammed down inside a cabinet and you can't do it out in the open because the cable that is physically attached to the monitor isn't long enough
Well, in theory DVI will be replaced by an Intel-backed HDMI-equivalent (without the licensing fees), which just plugs in like USB. So no fiddling with screws. I rarely bother with them anyways unless it's a proper long-term setup; never on my laptop which is always getting unplugged. Just being pedantic, but it's a DB-15 plug, not DB-9, and only for analog displays. There is indeed a decent amount of shielding, but there's also fifteen wires in there, and something like 27 for DVI. I'm fairly sure they're also wrapped in a way to reduce the effects of crosstalk and whatnot, just as (properly-wired) network cables are, with their twisted pairs. The thickness is really the least of my worries, but whatever It is indeed bandwidth, not to mention that USB would be a horrible way to do it. Monitors with two million pixels are best handled with some degree of parallelism, which I'm 99% sure is how DVI and HDMI both function. I know VGA separates the color channels (though I dunno if it's into RGB or YPrPb, not that it really matters) and adds in syncing and whatnot. With a serial interface like USB, you'd need to have three bytes per pixel (probably more if/when HDR displays come along, since I'm sure it would use more than 8-bit-per-channel color) per refresh, times at least sixty refreshes per second. So, on my 24", you're talking 1920x1200 px x 3B x 60Hz = 414MBps (ElThompsono's math is off, since the alpha-transparency is handled before signal is output; thus it's 24-bit color or three-byte color (vs 32b/4B) and his units are off). The max. theoretical bandwidth is 480Mbps per controller. 60MBps. Theoretical - real world, maybe 40MBps. Not even a tenth of the way there. Maybe a fifth or so for low-res displays. And ElT nailed it with power bricks... it's indeed cheaper. I personally have a strip outlet with extra-wide spacing on the side sockets so it can fit three bricks down either side (plus another five normal plugs down the middle).
I think there is something like USB-Ware for Monitors is it for desktop monitors? http://www.ami.com/products/services/usb/monitors.cfm
