Breakthroughs and major achievements within the computer graphics experience actually arise fairly seldom. The last principal update was a move to multi-GPU rendering: Crossfire, Dual GPU cards, and nVidia's SLI technology. The drawbacks having these technologies are rather evident. More than one motherboard is necessary for both Crossfire and SLI compositions, and dual GPU cards are prohibitively expensive for all but the most hardcore enthusiasts. Another concern, plainly, is the fact that you end up consuming two cards worth of power greater than one.
On the subject of software, you end up with a choice: you can span a desktop across numerous screens, thus running various software across one or additional displays, nonetheless, frequently, spanning an application across above and beyond one screen means that it could not be accelerated. So anybody ended up with a non-enviable choice: speed or size. Unfortunately, you couldn't possess both.
Well, times have altered, my friends. AMD's Eyefinity technology is that subsequent level in mainstream, multi-monitor output. Eyefinity enables the customer to possess up to six screens controlled from one card, and thus enabling a massive region of more than 24 megapixels. If you take a chance to read AMD’s literature on Eyefinity, it says that “we are inexorably on the road to the ‘holodeck’ (as conceptualized on Star Trek).” Given that the Star Trek holodeck used physical feedback based on force fields and such, this might be reaching a bit much at the moment, still none-the-less, the technology is certainly moving along.
With Eyefinity, one video card could direct up to six screens, depending on the type of the card, of course. AMD's position is that all 5000 series video cards will support Eyefinity. The trick here is that it falls to the graphics card manufacturer to make a choice whether, and how, Eyefinity will be implemented on that particular card. As of September 2010, the time of this copy, only the ATI 5800 model line of video cards possess Eyefinity enabled in CrossFire mode. The HD 4000 chain of cards, and all of their predecessors, do not support the Eyefinity technology. As fantastic as that series of cards was, they simply do not have the horsepower, or the output connectivity for displays, needed to fuel more than two high resolution monitors.
So, how do we get 3 displays working off of a solitary video card, precisely what is this new DisplayPort we keep hearing about, and precisely why do we want to get it? For numerous years, Dual-Link DVI was the professional multi-monitor interface of choice, but that is about to change. Being digital, DVI doesn't have the requirement of a digital-to-analog converter per screen that VGA requires, but it does demand that there be a devoted clock source for each and every output (this factor is also factual of HDMI). According to AMD, the signaling demands of DVI involves so many I/O pins from the video card that extending the panel past two monitors was simply impactical. Engineers recognized this at ATI back in 2004, and started researching a number of ideas to remove and move beyond the DVI restrictions
So, do you need a DisplayPort connector so as to run EyeFinity? Will you need to purchase new monitors? No, you will not. There are DisplayPort to DVI and also DisplayPort to VGA adapters, generally called dongles. There are two different kinds of dongles for Eyefinity: passive and active. Just like any other form of dongle for your laptop, these adapters alter one type of connection into another kind of connection. Conventional video port types are based on a technique called Transition Minimized Differential Signaling (TMDS) and employ either DVI or HDMI interfaces. The problem here is that TMDS is very different than DisplayPort. For just one example, TMDS brings to bear raster scanning, whereas DisplayPort is packetized. The protocols are utterly diverse. Also, the power requirements are visibly different: TMDS typically runs at about 5V whereas DisplayPort is only 3.3V.
Passive dongles drive non-DisplayPort signals through the DisplayPort connectors by shifting signals from one format to the other. The graphics card is able to discern that a passive dongle is attached to the DP connector. At that point, instead of passing a 3.3V DisplayPort stream, the card outputs a 3.3V TMDS signal through that port and the passive dongle shifts the voltage level up to meet the TMDS spec.
Active dongles are made up of a DisplayPort receiver (which attaches to the graphics card) along with a TMDS transmitter, which integrates a digital-to-analog converter (DAC) for VGA output. That’s genuinely the main difference between the two types. Power is commonly given by a cable that connects to a USB port. With an active dongle, the adapter appears like a DisplayPort to the graphics card, so the card transmits DisplayPort signals natively. In the passive situation, the card outputs TMDS for HDMI or DVI displays.
So the pimary thing to know about Eyefinity and dongles is that there’s a hard limit of two TMDS output streams, period. There's no give here. So, if you want to employ Eyefinity to set up a 2x1 “array” (yes, dual-panel Eyefinity looks a bit silly, but that’s how the driver sees it), it doesn’t matter what you hurl at the card. Two VGA screens? No issue. You could use a VGA adapter on a DVI port and an active VGA dongle on a DisplayPort connection. Just keep your legacy output stream count in heed as you scale beyond two monitors. “If you’re already using two DVI connectors on the board, you can’t use a passive dongle because, in theory, that would be a third TMDS signal stream,” says Roger Quero, technical leader at AMD’s GPU Technologies unit. “You can have two passive dongles, and the remainder have to be active. Just like, if you’re pondering about the six-output card, that’s six mini DisplayPorts. Two of those connections could be passive, putting out TMDS over those ports, then the rest have to be active so that we think it’s a DisplayPort screen.
Author Resource:
Donald Fountain draws on over three decades of computer hardware and programming knowledge, managerial experience, and two Bachelor's Degrees, as well as six Associate's degrees for his writing. He is the founder and publisher of PlanetEyefinity.com , and DisplayPortMonitors.com , as well as a support supervisor for one of the largest web hosting firms in the nation.
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