Topic Title: Multimonitor Penalty - GPU and Ram forced into higher Mhz
Topic Summary: Running 2 displays from one card
Created On: 03/09/2014 09:14 PM
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 03/09/2014 09:14 PM
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fanta_WMD
Peon

Posts: 2
Joined: 03/09/2014

See my sig for my setup config.

In windows GPU1 @ 250Mhz Core and 150Mhz Memory - It is driving only one monitor

In windows GPU2 @400Mhz and 1250Mhz Memory - It is driving 2 displayport monitors

I've always known that the cards ramped up to 3d freqencys when running multiple screens. I was getting sick of the noise and heat from the second card when all I do is 2d stuff.

Then I found the below comment online ,it applies to HD6 series cards I believe.

"When using a TMDS-type monitor along with any other monitor, AMD has to raise their idle clockspeeds from 350MHz core and 600Mhz memory to 350MHz core and the full 5.5GHz speed for memory, with the power penalty for that being around 30W. Matched timing monitors used exclusively over DisplayPort will continue to be the only way to be able to use multiple monitors without incurring an idle penalty."

 

I have the latest drivers and both of my Displayport monitors are identical , why are my GPU and Ram clocks not dropping down ? both monitors at 1920x1200 @ 75Hz

 

Thanks

 

 

 



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Intel i7-930 on Asus P6TD deluxe


Kingston 12GB DDR3 Triple Channel


2x HD6950 2GB - Non Crossfire Triple Monitor Setup.


1x HP LP2475w 24" (DVI to GPU1)


1x HP LP2475w 24" (DisplayPort to GPU2)


1x HP LP2475w 24" (DisplayPort to GPU2)


Windows 8.1 64Bit on 2x256GB samsung SSD


 


 


 


 



Edited: 03/10/2014 at 03:26 AM by fanta_WMD
 03/09/2014 10:36 PM
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black_zion
80 Column Mind

Posts: 12552
Joined: 04/17/2008

It is normal for cards to run at higher frequencies when driving more than one monitor.

-------------------------
ASUS Sabertooth 990FX/Gen3 R2, FX-8350 w/ Corsair H60, 8 GiB G.SKILL RipjawsX DDR3-2133, XFX HD 7970 Ghz, 512GB Vertex 4, 256GB Vector, 240GB Agility 3, Creative X-Fi Titanium w/ Creative Gigaworks S750, SeaSonic X750, HP ZR2440w, Win 7 Ultimate x64
 03/10/2014 03:26 AM
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fanta_WMD
Peon

Posts: 2
Joined: 03/09/2014

Originally posted by: black_zion It is normal for cards to run at higher frequencies when driving more than one monitor.

 

Yes I understand this. 

But....

supposedly, if you run both screens via Displayport it can run at normal slowed down 2D speeds.

read the qoute issued in by AMD in my first post.

 



-------------------------

Intel i7-930 on Asus P6TD deluxe


Kingston 12GB DDR3 Triple Channel


2x HD6950 2GB - Non Crossfire Triple Monitor Setup.


1x HP LP2475w 24" (DVI to GPU1)


1x HP LP2475w 24" (DisplayPort to GPU2)


1x HP LP2475w 24" (DisplayPort to GPU2)


Windows 8.1 64Bit on 2x256GB samsung SSD


 


 


 


 

 03/12/2014 01:57 AM
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Thanny
Alpha Geek

Posts: 1417
Joined: 07/13/2009

I just moved my second monitor from DVI to DP with an active adapter (i.e. the card sees it only as DP), and the clock speeds were still boosted at idle.

Either it doesn't work as indicated in the AMD quote, or there's something much more specific that needs to be done.

There was a thread a short while back here where someone claimed to have two monitors with 300/150 idle speeds.  Perhaps he had the magic combination.

 

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