GPU diode for GPU 2 shows intermittently (PowerColor HD 7950 CrossFire)

[mandrix]

I have two Power Color 7950's in crossfire. Monitoring is done via Aida64 through Aquasuite.

Upon first installing Aida64 updates both gpu diodes normally show  up, yet after a time the second gpu disappears from the Preferences / External applications section, and thus does not get written to WMI.

 

Sometimes I can fiddle with gpu-z or other apps and get the gpu 2 diode to show up, lately not so much.

 

Any fix for this?

[Fiery]

I think the issue may be CrossFire.  In CrossFire mode AMD GPUs tend to use a power-saving trick called ULPS.  When ULPS is active, it's absolutely not safe to detect any GPU properties for the non-primary GPU(s).  Measuring temperatures when ULPS is active could cause a BSoD or system lockup   This is a ULPS implementation limitation that cannot be fixed from software.

 

 

Regards,

Fiery

[mandrix]

Ah, OK. Thanks for your response. I believe I disabled ULPS a while back but not sure if it was on this machine or my other Crossfire rig. Been a while since I delved into it.

I guess I will be fine with just gpu 1, it's just that the second card normally runs hotter in my setup but only by 2C.

[Fiery]

ULPS needs to be disabled everytime you change (e.g. upgrade) the video driver (Catalyst).

[mandrix]

That would explain it. Thanks!