DVI dummy - what's the point?

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colinstu

2[H]4U
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I see some people use them on big multi-card machines, some don't. Why would one need them, what do they do? Only certain cards require them?
 
On vista, you cannot extend your monitor (and thus not run a GPU client) to cards that don't have a monitor attached. The dummy plugs fool vista into thinking there's a monitor attached. XP (32 and 64) don't suffer from this 'shortcoming"
 
SatTech said:
On vista, you cannot extend your monitor (and thus not run a GPU client) to cards that don't have a monitor attached. The dummy plugs fool vista into thinking there's a monitor attached. XP (32 and 64) don't suffer from this 'shortcoming"
Click to expand...

Can XP support 8 GPU's? How does this play for W7 too?
 
XP supports 8. I have no idea about W7. I believe the max for Vista is 5 so that will probably be the same in W7, but hopefully somebody who knows for sure will chime in.

I'm running 4 9800GX2s on a XP64 box good for 30-40K ppd.
 
It's not GPU's that get maxed out with Vista, its the monitor outputs.

With Vista, Windoze sees 3 monitor outputs per 9800GX2 card, a DVI + a HDMI + a DVI connector in that order.
So with only 8 monitor outputs max in Vista, Windoze sees 5x DVI + 3x HDMI outputs and its only the DVI outputs that FAH uses to fold on.
Hence only 5 cores working.
If Vista only sees one monitor output from a 9800GTX/GTX+ card then you could add 2 of them to 2 GX2 cards for 6 cores running.

XP only sees the DVI outputs.
So with 8 outputs max, you can get 4x GX2 cards running.

I haven't run Windoze7 yet so I dont know if it follows XP or Vista's rules for the GX2 card outputs.

I have not yet got any 295 cards, so I don't know how many outputs each version of Windoze sees with them.

Luck ............ :D
 
Since it is the output that is the issue, I wonder if there is a way to trick Vista (and from what I am hearing Win7) into skipping the HDMI outputs and looking at only the DVI outputs.

 
Tigerbiten said:
It's not GPU's that get maxed out with Vista, its the monitor outputs.

With Vista, Windoze sees 3 monitor outputs per 9800GX2 card, a DVI + a HDMI + a DVI connector in that order.
So with only 8 monitor outputs max in Vista, Windoze sees 5x DVI + 3x HDMI outputs and its only the DVI outputs that FAH uses to fold on.
Hence only 5 cores working.
If Vista only sees one monitor output from a 9800GTX/GTX+ card then you could add 2 of them to 2 GX2 cards for 6 cores running.

XP only sees the DVI outputs.
So with 8 outputs max, you can get 4x GX2 cards running.

I haven't run Windoze7 yet so I dont know if it follows XP or Vista's rules for the GX2 card outputs.

I have not yet got any 295 cards, so I don't know how many outputs each version of Windoze sees with them.

Luck ............ :D
Click to expand...

The 295's are the same sorta.
I had one, and its one core is mapped to the hdmi port....problem is you cant really put a dummy plug on hdmi so you must have it connected to a monitor


Damnnit I wish Nvidia would just gpgpu happen without the need for a monitor.
Its just a fucking stupid driver limitation that does absolutely nothing.
We know it can be done without a monitor.....look at Tesla C1060 its a GTX 280 without DVI connections.
/rant
 
You should be able to dummy plug a HDMI. Go to monoprice get a HDMI to DVI adapter, then just shove a normal dummy plug on it.

That is unless the HDMI plug has no interface with the resistors though all those adapters. (might very well be the case)
 
I think I've seen DIY guides for the HDMI dummy plugs
 
capreppy said:
I think I've seen DIY guides for the HDMI dummy plugs
Click to expand...

But you still end up with 3 outputs from 2 cores on 1 card.
It will make no difference to the number of cores useable in Vista or Win7 ...... :mad:

You either need to ..........
1, Stop Windoze detecting the HDMI output.
2, Upping the number of outputs that Windoze can work with.
3, Disable the output before Windoze detects it bymodding the card.

Luck ............... :D
 
Kendrak said:
You should be able to dummy plug a HDMI. Go to monoprice get a HDMI to DVI adapter, then just shove a normal dummy plug on it.

That is unless the HDMI plug has no interface with the resistors though all those adapters. (might very well be the case)
Click to expand...

Yea that does not do anything because on a vga dummy your putting resistors on the analog signal that detects a connected monitor.
However on HDMI its all digital and does not use those same "wires"
 
Somebody wondered a while ago if it was possible do disable outputs through hacking the registry. Anything ever come of this? It'd be nice, that's for sure.

 
Yeah, the whole dummy plug thing is a real PITA when it comes to hooking up GPU's. If nVidia can enable the cards to work without any output's, then why can't then just enable a driver feature to let the CUDA enabled GPU's to just tell Windows they don't have any outputs? It really shouldn't be that difficult, especially since they already have it enabled in Telsa cards.

I wonder if there could be some way of enabling it in the F@H client? Or some sort of add-on/registry hack/etc?
 
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