DVI to VGA Dummy.....56K!

[Naja002]

Post Edited to eliminate unnecessary steps...


Hey Everybody,

As Ya know, I had some Multi-GPU issues and managed to get them resolved. One of the long-term solutions was making and installing a "VGA Dummy". Very simple and easy to do, so I thought I would share some pix, and put the links in one thread.



Shadowtester's links:

VGA Dummy

FAH folding Forum



Google Diagram:




As stated in the prior thread (linked above): Radioshack apparently does not carry "75 ohm" resistors, but any resistors from ~50-150 ohms will work from what I understand. What I do know is that Radioshack carries 68ohm resistors and they do work.




Instead of using a VGA plug and then having to attach that to a VGA to DVI adapter--I couldn't foresee any reason why I couldn't just use a DVI to VGA adapter.....so, that's what I did:









As can be seen in the picture, I alternated the orientation of the actual ceramic resistors in order to create a "built-in" seperator or divider to help keep the leads from contacting each other.

So far its working Great! I've rebooted with the dummy installed and got exactly what I needed:

[DAK1640]

So the purpose of this is to 'Fool' the GPU into thinking there is a monitor out there? If so, you're a genious...This is exactly what I needed.

[Naja002]

No Genius here.....just a follower! Thanx goes to Shadowtester for sharing the info in the other thread!

And: Yes. Its to fool the other gpus into thinking that there's a monitor hooked up, so the desktop can be "Extended" in Vista. That's needed in order to get things to work properly with multiple gpus. Check out this thread: Need Multi-GPU Help......56K!

[MaK2000]

This gets asked a lot around here. Sticky?

[CyberDruid]

I'll be checking that out shortly...

[DAK1640]

Most excellent....99 cents at radioshack & I'm running... Nice photo's BTW Naja002

[WFO]

You have too much time on your hands Naja. Or I'm just a lazy S_B. I just doubled over the ends of my resisters and pinched them with needle nose pliers to get a proper interference fit in the existing holes. It only took about 5 minutes a plug and no soldering.

[Naja002]

I understand. I made a 2nd one in probably less than 5 mins. Above is a first timer's approach. I like to try to do somethings right the first time and be done with it. In this case--I've had enough issues with these crunchers that I figured it would be worth the trouble to solder the resistors in and be done with it. I realized the lack of need for all of that, but not until after getting out the dremel. As you can tell from the pix--I didn't bother to solder. The resistor leads fit very snuggly. But I was originally heeding these words:

A quick and dirty way to make a dummy plug is to just use the dvi to vga adapter and insert the resistors directly into the correct connection holes however its not a real good long term option since nothing except a little friction is holding the resistors and they are not protected from shorting out against each other if one get bent by accident a hooded db15 connector with the resistors soldered in is a much better long term option and not very expensive parts needed run around $5.00 at Radio Shack.

Shorting against each other is why I decided to alternate the ceramic location. Since I just used a DVI to VGA adapter I still need to figure out some type of "hood" or protective cover. But in its current home--its a very low-traffic area....so, it really shouldn't be an issue.

[Knight203]

would it be ok to wrap the transistors in electrical tape so they dont short?

[Shadowtester]

They are not transistors they are resistors and yes wrapping them with electrical tape would be fine. Another possible better option would be to insert one resistor then use heat shrink tubing on it then do the same on the next and then the final one so each resistor is covered in heat shrink tubing to protect it and prevent possible shorting between each other then to reinforce the entire setup you could use a larger piece of heat shrink tubing and cover the entire end and resistors as well to add strength to it and help prevent any possible shifting of the resistors since they are only friction fitted into the plug.

[Knight203]

They are not transistors they are resistors and yes wrapping them with electrical tape would be fine. Another possible better option would be to insert one resistor then use heat shrink tubing on it then do the same on the next and then the final one so each resistor is covered in heat shrink tubing to protect it and prevent possible shorting between each other then to reinforce the entire setup you could use a larger piece of heat shrink tubing and cover the entire end and resistors as well to add strength to it and help prevent any possible shifting of the resistors since they are only friction fitted into the plug.

resistors...lmao woops, thanks for the info and for dealing with my stupidity

[Polizei]

So wait... You can't just install a second GPU in non-SLI and non-Crossfire mode and have it fold? You have to fool it into thinking a monitor is attached?

I was thinking about picking up a cheap 8800GT or GS and having that fold in non-SLI/Crossfire on my P5Q-Deluxe for the extra 5kppd. Would I have to do this "mod" to get that to work?

[Shadowtester]

If your going to be using WinXP you will not need the VGA dummy plug but if your going to use Vista yes you need to use a VGA dummy plug to fool vista into thinking you have a monitor connected to the second video card so you can extend the desktop on to the second video card activating it. Also if your going to use multiple Video Cards make sure they have the same number of shaders or you will have problems its best to make sure the cards are exactly the same to maximize production.

[Marvin_The_Martian]

You can use the tv out cable that came with your card, plug that in and force tv detection ( works over here atleast ). Other then that, sticky please

[kup]

If your going to be using WinXP you will not need the VGA dummy plug but if your going to use Vista yes you need to use a VGA dummy plug to fool vista into thinking you have a monitor connected to the second video card so you can extend the desktop on to the second video card activating it. Also if your going to use multiple Video Cards make sure they have the same number of shaders or you will have problems its best to make sure the cards are exactly the same to maximize production.

I had to use the Dummy method with XP SP3 and 2x 3870XT cards. Extending it and rebooting still lost it the second 'display'. Used the dummy (with 90 Ohm resistors) and it worked like a charm.

You can use the tv out cable that came with your card, plug that in and force tv detection ( works over here atleast ). Other then that, sticky please

Confirmed this one working too. Nice one, MTM.

[Naja002]

Nice.... Thanx for letting us know and posting it here.

[[XC] Synthetickiller]

I might have time this weekend to pick up some resistors. Do I have to actually take apart the dvi-vga plug or can I just shove both ends into the appropriot ports? The leads should be long enough...

I might actually need the plug later on and I'd rather not destroy it.

[Shadowtester]

You do not need to take the DVI adapter apart the resistor ends will shove into the connector spots on the vga port. Just make sure you add some electrical tape to prevent them from shorting against each other and maybe to prevent them from being pulled out by accident. Heat shrink tubing would work for that as well if not better than electrical tape.

[[XC] Synthetickiller]

Thanks!

I'll have to run out this weekend to pick some up.

[bot@xs]

sorry to bring this back.
question is this still needed .. the only option to run multiple clients on multiple GPU's?
i just installed a second card but it doesn't show up

[cirthix]

or just use one on hotplug :/

[PoppaGeek]

Still required to extend the desktop. I use a KVM.

[SocketMan]

I use 2 inputs on the (same) monitor,plugged into 2 cards (DVI+VGA).
I also use the HDMIs on the TV,since it has about 5
Have been stocking on the cables at ~9.99CDN at Ncix (local store,no shipping),over the months.

[Sir_Loin]

sorry to bring this back.
question is this still needed .. the only option to run multiple clients on multiple GPU's?
i just installed a second card but it doesn't show up

It depends on your OS if you need them or not. The boys will steer you right

[bot@xs]

running xp pro atm. FAH guide says it would be the best option.
i'd like to rdp into it and go without any display at all.