Added Second 7970... Issues

[EXCellR8]

I added a second reference design ASUS HD7970 (HD7970-3GD5) to my AMD 6-core machine but there's a little bit of a problem. After enabling crossfire in the control panel it seems that I cannot get any readings from the second card or manually adjust the fan speed. If I enable the option I can move the slider but it doesn't do anything. Also, the little meters have no readings for clock speeds and the temperature is at 0.

I played with MSI afterburner a little bit to see if there was a way to get the fan spinning. The slider for the secondary card would just "snap" back to the default value when I moved it up, which was weird. I did get the fan spinning briefly but after a few minutes it spun down again. Meanwhile the primary card is fine.

So, I feel like this is a software issue but the fact that I can't see the clock speeds or adjust the fan in AMD control center doesn't instill much confidence. Could this be a power supply under-powering issue? The machine is currently using a SeaSonic X-750 which should run a pair of non OC 7970 but there is a lot of other hardware and an overclocked 6350 processor.

Any input is greatly appreciated...

 

[Durvelle27]

I see a bottleneck in your future bud but in MSI Afterburner check sync settings for similar graphics processors and both cards will be set to the top card including Core Clock, Mem clock, and Fan Speed

 

[railven]

I added a second reference design ASUS HD7970 (HD7970-3GD5) to my AMD 6-core machine but there's a little bit of a problem. After enabling crossfire in the control panel it seems that I cannot get any readings from the second card or manually adjust the fan speed. If I enable the option I can move the slider but it doesn't do anything. Also, the little meters have no readings for clock speeds and the temperature is at 0.

I played with MSI afterburner a little bit to see if there was a way to get the fan spinning. The slider for the secondary card would just "snap" back to the default value when I moved it up, which was weird. I did get the fan spinning briefly but after a few minutes it spun down again. Meanwhile the primary card is fine.

So, I feel like this is a software issue but the fact that I can't see the clock speeds or adjust the fan in AMD control center doesn't instill much confidence. Could this be a power supply under-powering issue? The machine is currently using a SeaSonic X-750 which should run a pair of non OC 7970 but there is a lot of other hardware and an overclocked 6350 processor.

Any input is greatly appreciated...

What you are experiencing is the ZeroCore function of AMD CFX.

The second card will essentially be off until it is needed (ie you go into a game and use CFX.)

If you wish to get the feeling that the card is doing something outside of just adding heat/noise/power-draw you can disable ULPS. Beside expanding OCing, in my experiments I've found little reason to disable ULPS.

On my rig, I get weird anomalies with ULPS disabled, such as high idle clocks (700/500) on my primary card, 2nd card idle fines (300/150), and then I couldn't exactly set voltages so I just said screw it, running it plain vanilla.

 

[EXCellR8]

I shouldn't have any issues with bottleneck... probably should have mentioned that I game with Eyefinity (6048x1080). I wanted to add a second card because the single card can't quite handle some of the more demanding titles. Also, if I enable AA the cards have plenty of work to do.

I looked around some more and I guess there is something called "Ultra Low Power Save" which actually turns the second card off when it's not needed. That would definitely explain why it seemed the fan was completely off and why I couldn't see any clock values. Apparently you can modify the registry to disable it, and this is a tool that makes it easy:

http://ulps.achromaticcomputing.com/

Haven't tried it yet, but most people who have said it works perfect. Coulda fooled me...

EDIT: sorry railven, I must have been tying as you submitted. I think I will go ahead and try disabling ULPS and if I encounter any anomalies revert. The ULPS tool allows you to backup the settings so I can go back if need be.

 

[BrightCandle]

ULPS is unfortunately not the only issue you are likely to face. The unfixable tearing is quite likely to annoy as is the stutter. You may also find your cards underclocking in certain games causing unplayable performance.

Right now adding that second card may well bring you no performance benefit at all. The card will show as having rendered twice as many frames but in practice they don't appear. Crossfire is horrible right now and is beat avoided until the fix comes out and tests confirm its actually working.

 

[3DVagabond]

ULPS is unfortunately not the only issue you are likely to face. The unfixable tearing is quite likely to annoy as is the stutter. You may also find your cards underclocking in certain games causing unplayable performance.

Right now adding that second card may well bring you no performance benefit at all. The card will show as having rendered twice as many frames but in practice they don't appear. Crossfire is horrible right now and is beat avoided until the fix comes out and tests confirm its actually working.

In before all of the people who are currently running crossfire disagree with you.

Seriously though, you are painting with too broad of a brush. It depends on the players preference. Personally, I would adjust game settings to be able to maintain 60fps and use vsync.

 

[EXCellR8]

I understand AMD is to address some issues with crossfire very soon with what will hopefully be new drivers. Having said that I've had mixed results with CF in the past when I used to run two 4870. It seemed like more of a "lack of compatibility" issue with games then, but honestly I don't expect it to be perfect.

As for the ULPS function, I'm just leaving it alone for now. I don't overclock my graphics and honestly the second card doesn't need to be running when no games are being played. And also, I don't need the additional noise and heat...

 

[Durvelle27]

I understand AMD is to address some issues with crossfire very soon with what will hopefully be new drivers. Having said that I've had mixed results with CF in the past when I used to run two 4870. It seemed like more of a "lack of compatibility" issue with games then, but honestly I don't expect it to be perfect.

As for the ULPS function, I'm just leaving it alone for now. I don't overclock my graphics and honestly the second card doesn't need to be running when no games are being played. And also, I don't need the additional noise and heat...

well in afterburner just click sync settings so you want have to mess with the fan profiles or clocks separately

 

[Elfear]

ULPS is unfortunately not the only issue you are likely to face. The unfixable tearing is quite likely to annoy as is the stutter. You may also find your cards underclocking in certain games causing unplayable performance.

Right now adding that second card may well bring you no performance benefit at all. The card will show as having rendered twice as many frames but in practice they don't appear. Crossfire is horrible right now and is beat avoided until the fix comes out and tests confirm its actually working.

Pheew! Glad you told me. Here I thought I was adding eye candy with multi-GPU and the whole time AMD had me fooled. And they've fooled me in so many games!

OP - You might try Sapphire Trixx rather than AB. I've found it works a little better for Xfire overclocking.

 

[EXCellR8]

I don't really need or want to OC my graphics, I was just concerned about the fan speed and readouts since I was not aware about the whole CF power save function at the time. I was worried that the card was active with no fan spinning, which is likely to cause damage.

Regardless of whether or not it's worth it to use crossfire, I'm prepared to not expect things to be hassle-free, perfectly stable or 100% reliable. I already face some drawbacks with Eyefinity and CF has yielded mixed results in the past but I do want to make sure the hardware is functioning properly.

Thanks for the input!

 

[jackstar7]

Are you just using CCC to check what's happening? You might want to also get GPU-Z going and use its ability to show you what's happening.

I don't think you mentioned it, so I just want to be sure you're using all the tools you could have available to you.

 

[EXCellR8]

I have GPU-Z somewhere on the machine but I suppose downloading the latest version would be best. I like AB because it's got the realtime display applet for the keyboard, opposed to OSD, but I think GPU-Z may have that too. It's useful because I've caught some anomalies in the past by simply looking at the LCD and GPU usage, temps, clocks etc.

But CCC or whatever it's dubbed as now was my initial source, only because I needed it to enable CF and rearrange my display group. They could have added a little note in there about the ZeroCore, unless I just missed it somewhere...

 

[Termie]

I haven't seen anyone give the easiest solution, but maybe I missed it. The reason you're not getting a reading is indeed zero core, but you don't need to disable ulps. Just put a load on the cards when you start afterburner.

I do think you may encounter some cpu bottlenecking even at surround resolutions if you enable maximum settings, as certain settings tax the cpu nearly as much as the gpu. That doesn't mean it won't be fun to play around with that much gpu power. Just use vsync to smooth things out.

 

[EXCellR8]

Hmm, yea I hadn't thought of loading up the cards but I don't think it matters since CF is not active outside of fullscreen 3d... unless I am mistaken. It's been awhile since I configured dual cards but so far so good. I tried a little gaming yesterday and didn't encounter any real issues. Seemed pretty smooth.

I will continue to monitor the performance and post any major problems that arise, but for now I think I'm good.

 

[EXCellR8]

After some testing the cards seem to be working just fine without any tweaks, which is good. I do have one issue though it seems that my current UPS is not quite up to the task of powering this behemoth when both cards are online and under heavier load. The readout on the UPS itself shows, at times, over 600w being used. It's a 600w max UPS so obviously I'll need to fix that.

So that's something I overlooked but I was planning on picking up another UPS unit anyway, so I'll just have to get a more powerful one. The current one is good enough for both cards in 2D but as soon as they draw from the PSU all bets are off. If I lost power whilst gaming the system would probably crash; that's no good.

 

[BigChickenJim]

ULPS is unfortunately not the only issue you are likely to face. The unfixable tearing is quite likely to annoy as is the stutter. You may also find your cards underclocking in certain games causing unplayable performance.

Right now adding that second card may well bring you no performance benefit at all. The card will show as having rendered twice as many frames but in practice they don't appear. Crossfire is horrible right now and is beat avoided until the fix comes out and tests confirm its actually working.

Bah, same old bunk. This is simply not true in 95% of modern games. Use a frame limiter or dynamic V-sync if you have tearing or microstutter issues between now and the frame pace driver's release later this week. It's a two-second fix, and it will likely be unnecessary once the driver drops.

There's been plenty of testing to confirm CFX's benefits, and I can confirm through personal experience that it offers spectacular gains with very few drawbacks in most titles. All the fear mongering about phantom frames and microstutter is being perpetuated by people who I suspect haven't used CFX for years, if at all. As long as you don't mind using RadeonPro in the background when necessary you'll have next to no real-world issues in the overwhelming majority of modern titles while enjoying performance on the level of $1000+ single GPU solutions. It's as simple as that.

OP, good choice on the CFX config. However, I'd leave the slave card in the default idle state. It uses far less power and reduces heat substantially while it isn't running, and I suspect that forcing it to run during mundane tasks will lead to some odd issues in standard desktop applications. You can always start a game and then alt-tab out to start the monitoring software if you need to track the second card's activity.