I can't set my 2nd GPU's voltage in Crossfire

[SickBeast]

Hi Guys,

I recently got a 7870 to crossfire with my 7850.

I can't seem to set the voltage for GPU 2 (the 7850). I've tried MSI Afterburner, ASUS GPU Tweak, and Sapphire Trixx.

If any of you know how to fix this I would appreciate it. The voltage is completely greyed out in Afterburner and there isn't even a voltage slider in the other programs.

 

[Termie]

As I recall, I had that issue with my old 5850 crossfire. One card had unlocked voltage, the other didn't. Running both meant I couldn't control voltage on either.

Do both of your cards offer voltage control? Do you have synchronize gpus checked in afterburner? That could be the problem. Their different default voltages would confuse things. Of course, you'll need to unlock voltage control too but I assume you did this already.

 

[SickBeast]

As I recall, I had that issue with my old 5850 crossfire. One card had unlocked voltage, the other didn't. Running both meant I couldn't control voltage on either.

Do both of your cards offer voltage control? Do you have synchronize gpus checked in afterburner? That could be the problem. Their different default voltages would confuse things. Of course, you'll need to unlock voltage control too but I assume you did this already.

Yes both offer voltage control. I do not have the "sychronize" setting checked in Afterburner. I tried it both checked and unchecked and it didn't work with either setting.

What is odd is that GPU-Z is reporting that my 7850 is at 1.2v but I can't set it higher than 950mhz without it crashing. Before it was stable at 1150mhz at 1.2v.

I can't even monitor GPU 2's voltage in Afterburner.

This issue is really irritating. I really hope there is a solution.

 

[Termie]

Did you try running GPU 2 (I assume that's the 7870) on its own? Make sure you can monitor and control its voltage. Actually, I was only able to monitor one card's voltage when I had crossfire, and that was kind of odd, since you shouldn't need unlocked voltage to just see what the voltage is.

There are a handful of people on the forum who've tried 7000-series crossfire, so hopefully someone has an answer, but I wouldn't surprised if you lose some control when you have two cards.

 

[Elfear]

OP - I've got voltage control for all three of my 7970s using AB. Follow the guide in this thread and see if that helps.

 

[SickBeast]

OP - I've got voltage control for all three of my 7970s using AB. Follow the guide in this thread and see if that helps.

I tried your guide and it didn't help.

The closest I've come was after flashing both cards to an Asus 7870 rom, and then Asus GPU Tweak showed all the sliders for the voltage and everything, but when I adjusted it for the 7850 it just stayed locked at 1.210v. What's really strange is that I can't exceed 950mhz at that voltage whereas I was easily hitting 1150mhz stable for months previously when I just had the single card.

I might have to sell my 7850 if I can't get this worked out.

 

[Termie]

Does the 7850 still hit 1200 on its own? If so, it must just be a glitch in the handling of mixed cards.

 

[Elfear]

I tried your guide and it didn't help.

The closest I've come was after flashing both cards to an Asus 7870 rom, and then Asus GPU Tweak showed all the sliders for the voltage and everything, but when I adjusted it for the 7850 it just stayed locked at 1.210v. What's really strange is that I can't exceed 950mhz at that voltage whereas I was easily hitting 1150mhz stable for months previously when I just had the single card.

I might have to sell my 7850 if I can't get this worked out.

Have you tried unlocking unofficial overclocking mode? To unlock AB do the following steps:

1) Uninstall any other GPU overclocking software you have like Trixx or GPU Tweak.
2) Make sure AB is not running.
3) Open up the Afterburner.cfg file (located in Program Files/MSI Afterburner) and edit these two lines near the bottom of the file to look like this:

UnofficialOverclockingEULA = I confirm that I am aware of unofficial overclocking limitations and fully understand that MSI will not provide me any support on it
UnofficialOverclockingMode = 2

4) Save and close the file.
5) Start AB up, go to Settings, and make sure to check the box next to "Unlock Voltage Control" and "Unlock Voltage Monitoring" for both cards.

Give that a shot and see if it works.

 

[blackened23]

I tried your guide and it didn't help.

The closest I've come was after flashing both cards to an Asus 7870 rom, and then Asus GPU Tweak showed all the sliders for the voltage and everything, but when I adjusted it for the 7850 it just stayed locked at 1.210v. What's really strange is that I can't exceed 950mhz at that voltage whereas I was easily hitting 1150mhz stable for months previously when I just had the single card.

I might have to sell my 7850 if I can't get this worked out.

Try this:

Download latest version of asus GPU tweak under their 7970 download section.

Install, reboot.

open GPU tweak, and select "advanced" and then select "extend overclocking range" in the tuning section. This will unlock voltage for both cards, at least it always did back when I had 7970s (should work 78xx as well).

At this point you can uninstall gpu tweak, the only purpose of using it is to apply the unlock registry entries.

 

[blackened23]

Another method: create a shortcut for afterburner on your desktop, and have that shortcut use the command line parameter afterburner -xcl or /xcl (forget which)

You can also try sapphire trixx if afterburner doesn't work, it definitely works with voltage. Its similar to afterburner.

 

[SickBeast]

Thanks everyone for your replies.

The best I've been able to do was to flash both cards to an MSI bios and then "synchronize" the voltage between the cards. I have them both running at 1150mhz at 1.17v which is ideal anyhow. I wouldn't really want to push the cards more than that without upgrading my cooling a bit.

I might try Sapphire bioses and then use Trixx. For now I'm happy and I'm tired of all this tweaking.

blackened - the latest version of Asus GPU Tweak doesn't have the range enhancement. I had to use version 2.0.83 but it did work, except it only lets me up to 1170mhz in Afterburner now, unless I need to reinstall it to get even higher clocks.

**edit** thanks elfear for suggesting the "unofficial" mode for Afterburner. I can now clock it up as high as I want.

 

[jacktesterson]

Welcome to part of my 7850 CF experience.

 

[Elfear]

Thanks everyone for your replies.

The best I've been able to do was to flash both cards to an MSI bios and then "synchronize" the voltage between the cards. I have them both running at 1150mhz at 1.17v which is ideal anyhow. I wouldn't really want to push the cards more than that without upgrading my cooling a bit.

I might try Sapphire bioses and then use Trixx. For now I'm happy and I'm tired of all this tweaking.

blackened - the latest version of Asus GPU Tweak doesn't have the range enhancement. I had to use version 2.0.83 but it did work, except it only lets me up to 1170mhz in Afterburner now, unless I need to reinstall it to get even higher clocks.

**edit** thanks elfear for suggesting the "unofficial" mode for Afterburner. I can now clock it up as high as I want.

Glad you got it sorted. :thumbsup:

Now tell us your impressions.

 

[SickBeast]

Glad you got it sorted. :thumbsup:

Now tell us your impressions.

It's a great setup. I can run all games well, although Crysis 2 still dips down to 30fps in some places which I was quite surprised at.

Crysis runs like a dream at 1920x1080 with 4xAA and maxed out with mods. It looks amazing.

All other games run great.

I kinda wish I had 7950 crossfire instead but I can definitely live with this kind of performance for now.

The bitcoins are icing on the cake.

The drivers seem very solid by the way. Scaling is very good and I haven't had any crashes, glitches, or microstutter.

These cards output a *lot* of heat when bitmining.