7950 - Multi-Monitor Power Consumption

[elgrandeburro]

Greets all. I recently read techPowerUp!'s review of the 7950. The following page caught my eye:
* http://www.techpowerup.com/reviews/AMD/HD_7950/25.html


I noticed the multi-monitor power consumption is dramatically higher than a single monitor:
* Is this a hardware issue, or something that could be fixed via software/driver?
* One monitor sits at 11w, two monitors at 46w, does a third even push it higher?


Solutions:
* Is there anything one can do to keep consumption down during idle operations, office activities, movie watching, etc?
* The only thing I can think of is to create "overclocking" profiles, that dramatically underclock the card; is this the right approach?
* Is there a way to configure one's setup to automatically switch between desktop overclocking profiles, vs gaming?


Thanks in advance.

 

[cdawall]

It is typical of all cards. That much display requires a higher clockspeed than a single monitor.

 

[elgrandeburro]

It is typical of all cards. That much display requires a higher clockspeed than a single monitor.

True enough. It's just when you compare the idle power consumption of single and dual monitors of the 660 Ti, the power difference is nominal:
* MSI GeForce GTX 660 Ti Power Edition 2 GB: one monitor 12w, two 13w
* ZOTAC GeForce GTX 660 Ti AMP! Edition 2 GB: one monitor 14w, two 15w

I forgot to mention, the values I'm referencing here are the reported wattage at idle.

 

[cdawall]

The GTS 450 goes from 11 to 35w, the GTX 470 29w to 92w. New cards do different things. Nvidia currently has a better profile on the cards for a multimonitor setup.

 

[erixx]

Add to that the monitors own consumption, for energy awareness. Mine (30" LED) uses 75W, almost the same as my computer tower idling. And it is "on" the whole day... Bills, bills, bills....

 

[elgrandeburro]

The GTS 450 goes from 11 to 35w, the GTX 470 29w to 92w. New cards do different things. Nvidia currently has a better profile on the cards for a multimonitor setup.

Gotcha. Man, that's a bit of a bummer. As I will spend most of my time in non-gaming situations, I believe I may have to return this card. Personally, I think the 7950 offered the best performance for the dollar, but the power overhead for daily use seems an unfortunate draw back.

 

[W1zzard]

It is really that high.

The card has a single-monitor idle clock/voltage profile and one for multi-monitor, which is higher. A third monitor will not increase GPU power

Our more recent reviews have a table with these profiles, check a recent AMD review, one of the last pages “Clock profiles”. Your HD 7950 will be similar.

In theory you could adjust these profiles but I’m not sure which OC software supports changing that parameter. Also it adds the complexity of having another software running on startup. Changing the “normal” clock just changes the 3D clocks, not the other profiles.

These profiles are switched automagically by the driver.

If you are using a multi-monitor setup, many hours a day, most of the time not gaming, then my best suggestion is to get an NVIDIA card. NVIDIA has much better power consumption in these scenarios.

If you run the same monitor, at the same resolution, with the same refresh rate.. basically same everything. It's possible that the driver will go to the single-monitor profile (I know for a fact NVIDIA did, not sure about AMD) Use GPU-Z, Sensors tab to check.

 

[elgrandeburro]

W1zzard, much appreciation for the information you've shared.

Today I sent the card back. While it was known to me the 7950 consumed more power while gaming, most reviews I perused didn't address multi-monitor power consumption regarding non-gaming use.

Given the latter is where I'll spend the majority of my time, I felt the tradeoff just wasn't worth it. Unfortunately I didn't know this before I bought it, but now I'm a bit more knowledgeable.

Cheers to the thorough review process, and thinking through all aspects of how a graphics card interplays within a system.