New Video Card - New TV

[Ken C]

Just purchased a new video card, figured a new TV REQUIRED a new card . Anyhow, the new card has two, dual link DVI connectors. I have a single link DVI to HDMI cable. Is the major difference between single and dual link bandwidth ? As the HTPC is running at 1920 x 1080, which is the upper limit for single link, no problem ?

And, if needed, where's a good site to get a dual link DVI to HDMI cable at less than BB prices ?

[Conejo]

Plagiarized content from a google search:

http://www.whichtv.com.au/dvi.php
Dual-Link DVI

It gets more complicated. DVI-D and DVI-I support a dual-link mode known as DVI-DL. This doubles the bandwidth of the connection from 4.9Gbps to 9.9Gbps, and is generally only used for high resolution PC displays (which have a much higher resolution than even the best TV's and projectors), using resolutions above 1080p, or refresh rates above 165Hz. DVI-DL is rare and generally won't play into your buying decisions unless you are planning on buying a display of 1080p or greater.

HDMI Connector
Created as an update to DVI technology (primarily to make the plug smaller for consumer devices), HDMI is backwardly compatible with DVI, so that HDMI and DVI connectors can be interchanged with an adaptor. Usually found on high end TV's, HDMI is becoming more common on cheaper items such as digital set-top boxes, etc. and is expected to become the standard connector for most digital media devices in the home.

The HDMI connector has two forms, a standard Type A HDMI connector with 19 pins, and a Type B version with 29 pins, designed to carry resolutions above 1080p or refresh rates above 165Hz. With a bandwidth of 4.9Gbps (gigabits per second) - more than twice the bandwidth required for a high-definition TV signal - for the Type A version, and 9.9Gbps for Type B, HDMI will likely be expanded to new applications in the future.

It appears that the HDMI-A specs (being limited to 4.9Gbps) won't take full advantage of the DVI-DL outputs. At least not 'today'.

[stanger89]

Doesn't matter, odds are your TV isn't dual-link anyway.

If you want a cable, monoprice.com is the place to go.

[Djc208]

From http://www.datapro.net/techinfo/dvi_info.html

The Digital formats are available in DVI-D Single-Link and Dual-Link as well as DVI-I Single-Link and Dual-Link format connectors. These DVI cables send information using a digital information format called TMDS (transition minimized differential signaling). Single link cables use one TMDS 165Mhz transmitter, while dual links use two. The dual link DVI pins effectively double the power of transmission and provide an increase of speed and signal quality; i.e. a DVI single link 60-Hz LCD can display a resolution of 1920 x 1080, while a DVI dual link can display a resolution of 2048 x 1536.

The only time I've heard that a dual link cable is necessary is running large (30") LCD computer monitors where the native resolution is really high. So you shouldn't need the capability for an HDTV since the max capacity of single link DVI is equivalent to the max any current HDTV can use.

[sandor]

yeah, apple had to get a video card made with dual-link DVI when they first introduced their 30" LCD monitor (2560 x 1600) they actually shipped the card with two dual-link DVI ports to support 2x30" monitors.

I think televisions will be stuck at 1920x1080 for quite a while, though as 120 mhz refresh rates grow more common on televisions, bandwith may become more of an issue (though HDMI 1.3 is supposed to address this already - due to the extra bandwidth needed for lossless surround sound on Blu-ray and HD DVD.)

[Conejo]

Wikipedia is there for those who need pictures to follow along.

Digital Visual Interface



Here are some of the possible resolutions from the specifications:

* Example display modes (single link):
o HDTV (1920 × 1080) @ 60 Hz with 5% LCD blanking (131 MHz)
o UXGA (1600 × 1200) @ 60 Hz with GTF blanking (161 MHz)
o WUXGA (1920 × 1200) @ 60 Hz (154 MHz)
o SXGA (1280 × 1024) @ 85 Hz with GTF blanking (159 MHz)
o WXGA+ (1440 x 900) @ 60 Hz (107 MHz)
o WQUXGA (3840 × 2400) @ 17 Hz (164 MHz)

* Example display modes (dual link):
o QXGA (2048 × 1536) @ 75 Hz with GTF blanking (2×170 MHz)
o HDTV (1920 × 1080) @ 85 Hz with GTF blanking (2×126 MHz)
o WQXGA (2560 × 1600) @ 60 Hz with GTF blanking (2x174 MHz) (30" Apple, Dell, HP, Quinux, and Samsung LCDs)
o WQUXGA (3840 × 2400) @ 33 Hz with GTF blanking (2x159 MHz)

HDMI, on the other hand, is currently limited to 1920x1080p60 @24bit color, with HDMI 1.3(a/b) compliant systems raising that to 2560x1600p60 36/48bit color. Maybe when I can start running black-ops from my livingroom I'll need this. Those Satellite pictures can look pretty fuzzy. I'll put it on my wish list.

[Ken C]

Thanks, guys. Interesting, the connectors on the video card look like the DVI-I dual link so it may support the higher bandwidths. The TV only goes to 1920 x 1080 progressive. Hopefully, in a year or so, when this TV gets shunted to the bedroom and a new, super-size TV shows up in the family room, the higher bandwidth will be useful.

[autoboy]

I think televisions will be stuck at 1920x1080 for quite a while, though as 120 mhz refresh rates grow more common on televisions, bandwith may become more of an issue

I don't think any TVs will actually accept the 120hz refresh rate as an input.

[Ken C]

Finally got the new video card installed and hooked up to the new TV via DVI - HDMI. And, it looks pretty good. This is the closest its ever been to the direct cable PQ. In some cases, it almost looks better. The WF has also increased, although she still won't touch the Harmony 676 remote.

Anyhow, IMO, the digital connection, single link DVI to HDMI, running at 1920 x 1080, 60 Hz, progressive, yields better PQ then analog component.

Also, there is a new version of HDMI coming out ? Uses 23 contacts rather than 19 ? When will it end ??

If you are using an ATI AGP video card, use the 7.7 driver. Later versions have problems with AGP cards. Ain't it great ...