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Video: How to Install VGA Hotwire on ASUS GTX 780 DirectCU II OC

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hokiealumnus

Water Cooled Moderator
Joined
Oct 14, 2007
Hi all. I made this video as part of the upcoming review (which is getting close, but needs input from ASUS before moving forward) and thought I'd post it up. Of course, with the exception of the tiny PGR100 resistor which may or may not be necessary on other cards, this is the same for any card with VGA Hotwire.

Anyway, here's the video.


Since the VGA Hotwire points aren't labeled on this GPU, here is how everything needs to be hooked up.

Step 1: Short PGR152 solder pads.
Step 2: Hook up hotwire leads as labeled.
Step 3: Remove PGR100 resistor.
Step 4: Profit!

asus-gtx780-dcuiioc-vgahw01.jpg

Now, none of this does a whole heck of a lot of good without a BIOS that allows a power target of greater than 110%, which is what I'm waiting on input from ASUS for. For a review, I refuse to flash another manufacturer's BIOS, which forces you to lose software voltage control. If this "feature" is supported, even through back channels (and the BIOS dutifully hosted here, linked from the review & the forum), it's supported. If it's not, it's not much of a feature, now is it? Once ASUS responds and I'm able to actually use my new voltage control, I'll finish benching the card & publish the review. :thup:

Please let me know what you think. I'm a total and complete n00b at video shooting and video editing. I'm wide open to constructive criticism to help improve future videos. :salute:
 
Ohh god I hope this makes this card super badass.
I will feel 100x better about buying two...
COME ON EK!!! IM WAITING ON THE BLOCKS!!!
 
VGA Hotwire allows manual voltage control if you have a compatible ASUS Extreme motherboard. However, you can connect a variable resistor between the OV_ (OVG/OVM/OVL) points and ground to get control manually.

For those who want to do OV without ASUS ROG MB.

a. Connect a variable resistor between OVG pin and Ground pin to over-voltage GPU voltage.
  • A 1.2Kohm resistor will over-voltage GPU to around 1.23V. Smaller resistor can get higher voltage.
  • But please make sure that you measure voltage in 3D mode while adjust variable resistor.
  • Because the ratio of resistor value/voltage value is different between 3D mode and 2D mode.
  • Doing adjustment in 3D mode can make sure you get correct voltage and won’t burn your card.
  • (You can measure voltage on “GPU” pin.)
b. Connect a variable resistor between OVM pin and Ground pin to over-voltage Memory voltage.
  • A 5.5Kohm resistor will over-voltage Memory to around 1.7V. Smaller resistor can get higher voltage.
  • A 1.5Kohm resistor will over-voltage Memory to around 2.0V. More than 2.0V is not recommend.
c. Connect a variable resistor between OVL pin and Ground pin to over-voltage PLL voltage.
  • A 11Kohm resistor will over-voltage PLL to around 1.1V. Smaller resistor can get higher voltage.
  • A 4Kohm resistor will over-voltage PLL to around 1.2V. More than 1.2V is not recommend.

People are working on a VBIOS to help with the power target limitation. Here's hoping they come up with something. :)
 
I have this card, but this mod scares me. I'd break it if I tried. ;-)

Without any mods I've got it up to 1202 core and 7200 memory stable.
 
any news on the BIOS? or maybe you did something fun with the card since the original post?
 
I actually have a BIOS in-hand (just arrived yesterday) but can't try it b/c my board died. I won't upload and host it until I try it myself, but I do have one.
 
Cool. Looking forward to see how it goes.

Please keep us posted :thup:

BTW, how does ASUS extreme mobos help OC the cards? Through custom software?
I have ASUS Rampage IV Extreme and wonder how best to utilize it with these cards.

Thanks.
 
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Using the Rampage IV Extreme you would hook the VGA Hotwire wires up to the points on your motherboard. Then you can control the GPU's voltage either via BIOS or via AISuite. At least I think there are controls for it within AISuite; if not, you'll have to set voltage via BIOS before booting.
 
The moment you take a soldering iron to the card you can no longer complain about the power target, as it is very easy to bypass by soldering.
If you post/link some decently high res pics of both sides I'll outline what to do.
 
High res will have to come a bit later, I only have our 1000-px constrained versions uploaded right now. However, I believe the BIOS I have allows a power target of 200%, so it's not an issue regardless. I'll still upload them though; never hurts to have more than one way to skin a cat. :)
 
Looks like they did away with the A219s, so the only method left is to short the sense resistors. That's the rough equivilent of a BIOS with a power target of 100000000000000% or so. Full turbo, all the time, damn the torpedos.
Alternatively if you want ~200% you can solder a second identical sense resistor on top of each current one, that halves the amount of current sensed. I can't tell if they're R112 or R002 (0.112 ohms or 0.002 ohms), it almost looks like the PCIe slot power is R112 and the PCIe plug power is R002.
 
There are no AMD ASUS boards with VGA hotwire, that is correct. However, if you go the variable resistor route, it doesn't matter which board you use.
 
Ive done the mod but have issues with voltage control still. I using gpu pad to read voltage under load and set 10k variable resistor to max before soldering. under 3d load I increased voltage on resistor but only got to 1.114 volts or so max under 3d load. If I remove variable reisistor it boots up fine on stock voltage and can use asus gpu tweak to get to 1.212 which is a little less actual under load. Any ideas would be great. If I OHm OVG to Ground I get about 32Mohm which is the same for for OVM and OVL to ground
 
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