KVM my best option?

[KnickNut3]

In my new apartment I plan on having my computer and TV in the same room. I'd like to run a DVI output and sound to my TV for some impromptu movie watching, using the same wireless keyboard and mouse.

My current PC has a Radeon HD 4870 (EAH4870) with two DVI outputs running to my two-monitor setup, with a 5.1 onboard speaker system. The TV, a Sharp Aquos (LCC5255U), supports DVI and a 3.5" audio wire, as well as HDMI and composite.

My first thought is a KVM switch, though it's been years since I've set one up (back in PS/2 and VGA days). I'd optimally like the flexibility to put the TV and PC on opposite sides of the room and/or keep the TV as a 3rd monitor rather than switching with the TV, but I haven't seen many extra-long KVM wires, and I don't want to add a second video card to add a monitor if at all possible.

Any suggestions? Is KVM my best option? If so, a specific model you'd suggest? Another approach? Thanks.

 

[mfenn]

You can get a DVI to HDMI adapter and then run an HDMI cable. You can run HDMI across the room without issues.

 

[Slugbait]

A KVM switch is for controlling multiple computers with a single KB/mouse and monitor. You only have one computer.

I can't find your TV's resolution via DVI, but I suspect it's nowhere near 1920x1080. What you need is a DVI->HDMI cable.

A monitor switch box might be the answer, but I can see two problems: the box probably won't support 1920x1080 (maybe max of 1600x1200), but if it does, you need to futz with resolution settings each time you switch. In which case, a less expensive approach is just to get the DVI->HDMI cable, and swap it with the monitor cable whenever you wanna watch a movie (you'll still likely have to futz with resolution each time)

 

[KnickNut3]

Thanks for the responses.

If I use a DVI to HDMI adapter, will sound be outputted through the video card to the HDMI cable? Because the 3.5mm audio input and the DVI input are "linked," but there is no 3.5mm input linked to HDMI since the HDMI feed would usually include sound. At least that's how I understand it.

I'd prefer to not have to pull out my PC every time to switch wires if at all possible. Would a DVI splitter and audio splitter serve the same purpose to duplicate the output of my second monitor and TV? Would Windows 7 allow me to properly change the resolutions accordingly?
http://www.newegg.com/Product/Produc...82E16882750035
http://www.newegg.com/Product/Produc...82E16882200015

 

[mfenn]

A DVI splitter will only work properly if both displays support the same resolution (and all the other frequency and timing information that goes along with it). While it might work, I doubt it.

As for the audio, some GPUs do actually use some extra pins on the DVI connector solely for the purpose of passing through audio to HDMI, but if your 4870 didn't come with a DVI to HDMI adapter, I would imagine that it doesn't support this capability. The splitter would likely fubar that connection anyway.

It looks like you have 3 options to me:
- Get used to swapping cables
- Add a cheap secondary GPU with DVI/HDMI output
- Upgrade your 4870 to a 5000 or 6000 series Radeon (which support 3 displays and native HDMI output)

 

[Gillbot]

DVI KVM's are expensive.

Since you already have both outputs on your current card used, you can always use a 2nd simple PCI video card and run VGA over ethernet using a cheap-o Cat5 to VGA adapter. That's what I did on my PC. Then you'll basically have a three monitor setup but you don't need to use the 3rd (TV) all the time.

I grabbed a Cheapie PCI Video card, 50' Ethernet cable, 2 Cat5 to VGA adapters and a 50' audio cable for under $25 shipped from ebay. Ran the cable around the room to the other side where my 37" is and called it done.

 

[Zap]

- Add a cheap secondary GPU with DVI/HDMI output
- Upgrade your 4870 to a 5000 or 6000 series Radeon (which support 3 displays and native HDMI output)

These are very good suggestions. May I add the suggestion of using an HDMI switch box?

Switch boxes

HDMI <> DVI cables

Just go from computer DVI > HDMI cable > switch box. From switch box, go HDMI to the HDTV and HDMI > DVI cable to other monitor.

 

[Paperdoc]

As for the audio, some GPUs do actually use some extra pins on the DVI connector solely for the purpose of passing through audio to HDMI, but if your 4870 didn't come with a DVI to HDMI adapter, I would imagine that it doesn't support this capability. The splitter would likely fubar that connection anyway.

Let me add a note of hope here on audio, and some info. ATI has, for some time, included audio on certain pins of the DVI connector just so you can use a DVI-to-HDMI converter to get HDMI WITH sound. I know it is in a 4350-based card we have from XFX - we use that machine to feed our TV via this exact route (The TV does 1080p resolution, so it works great!) I have a 4670-based card from Diamond in this machine, and I'm sure it has audio on the DVI port. There are three "tricks" to remember doing this.
1. Not all adapters pass that sound signal through, because it is a non-standard addition to the original DVI port. You MUST get one that specifically says it is for this purpose - passing the audio signals from an ATI card's DVI port to an HDMI cable. When we first tried this with our TV comnputer it did not work, so I consulted the card maker, XFX. They assured me the signals are there and sent me the correct adapter and it works just fine.
2. On some ATI-based cards with two DVI outputs, the audio signal is only available on ONE of those ports. So identify which one in your card, or try both.
3. Very early designs for this used some kind of patch cord from the computer's regular audio output (mobo-based or card) to the video card to get the audio signal, but no current designs do this. In the 4000-series ATI-based cards there is an audio output chip on the video card. The drivers for the card include BOTH (separately) one for video and one for the audio system on it. (You may have to get the audio driver from the ATI website if you can't find it on the card's CD.) So you need to be sure the audio driver for your vid card is installed. THEN you will need to go into Windows Control Panel ... Sounds and Audio Devices ... Audio and select that vid card's audio output as the Windows audio device. That is the only way to get the audio to the pins in the DVI connector on the card. However, this does mean that your regular audio output system will NOT send out audio - Windows can only use one output device at a time.

 

[KnickNut3]

Thanks for the comments! For the trouble that I've read some people have had getting sound on Radeon 48xxs to work with HDMI, and it's just as cheap to get a second card, I might as well do that.

Are there any pitfalls in getting this Radeon 5450 card as a secondary card just for HDMI and continuing to use my faster 4870 for my PC monitors?
http://www.newegg.com/Product/Produc...82E16814102882

 

[mfenn]

Thanks for the comments! For the trouble that I've read some people have had getting sound on Radeon 48xxs to work with HDMI, and it's just as cheap to get a second card, I might as well do that.

Are there any pitfalls in getting this Radeon 5450 card as a secondary card just for HDMI and continuing to use my faster 4870 for my PC monitors?
http://www.newegg.com/Product/Produc...82E16814102882

As long as you've got the free PCIe slot, not really. It should work perfectly.