7950 Crossfire Enabled but not (if that makes sense)

[Apprentrice5]

Hi guys,

I will say before i start i have never used dual graphics cards in my system before.

I recently bought a second XFX 7950 graphics card for my system as it was on sale

I have installed the second card and plugged it in, and its recognized by my system that it is there.

In CCC, and GPU-Z it is saying that crossfire is enabled, but in speccy it is saying it isn't. and when I played Battlefield 3 for not even 5 minutes on ultra using Eyefinity it made my primary GPU to go up to 87 degrees C.

So i would say that it isn't enabled.

Any help would be appreciated

 

[smarteyeball]

In CCC, and GPU-Z it is saying that crossfire is enabled, but in speccy it is saying it isn't.

I'd trust CCC/GPU-Z over speccy.


To verify, Open GPU-Z and select the second card from the dropdown menu.

Under sensors, look for GPU Load. In the dropdown menu select "Show Highest Reading"



Run the game and either quit or alt-Tab and see what the GPU Load is for the 2nd card. If crossfire is not enabled then there will little to no usage shown. If it is enabled then it will show load usage.

To compare, you can run two instances of GPU-Z - one for each card. If the Load is the same or close to for both cards, then it's definitely working.

Or you can also use Afterburner to monitor both cards simultaneously. Once out of the game you can compare the gpu load for each card. Again, if there is little to zero load on the 2nd card - it's not enabled. If it's the same as the primary - it's enabled.

and when I played Battlefield 3 for not even 5 minutes on ultra using Eyefinity it made my primary GPU to go up to 87 degrees C.

Simply adding the second card is enough to make the primary card run hotter as the bottom card disturbs the airflow.

Jumps of 10-20c is not uncommon for dual cards.


Unfortunately one downside to multi cards is the extra heat and noise. You can either manually crank your fans up in CCC or use Afterburner to create a custom fan profile to help keep temps down.

I'd wager it is enabled.

 

[madcratebuilder]

With CrossFire the load is not equally distributed between cards. Normally card 0 runs at 100% and card 1 runs 40-80%. Adding the second card adds heat and blocks airflow. It helps to have a 200mm side fan blow directly on the two cards

 

[Apprentrice5]

Thank you for the detailed response

Run the game and either quit or alt-Tab and see what the GPU Load is for the 2nd card. If crossfire is not enabled then there will little to no usage shown. If it is enabled then it will show load usage

Ok, ill try this when i get home this evening, how long would you say is a suitable time to play for to get a good reading?

Unfortunately one downside to multi cards is the extra heat and noise. You can either manually crank your fans up in CCC or use Afterburner to create a custom fan profile to help keep temps down.

Ill just crank the fans up then. Not fussed about the noise while gaming cos i normally use a headset and have it quite loud anyway.

With CrossFire the load is not equally distributed between cards. Normally card 0 runs at 100% and card 1 runs 40-80%. Adding the second card adds heat and blocks airflow. It helps to have a 200mm side fan blow directly on the two cards

Thanks for the reply madcrate. Unfortunately my case does not allow for a fan to be mounted on to the side panel so this is not a viable option, I will however review what i can do to get more airflow over the cards.

 

[smarteyeball]

Ok, ill try this when i get home this evening, how long would you say is a suitable time to play for to get a good reading?

CF will trigger as soon as the cards hit the full 3D clocks. (ie in game, not menu) Less than a minute will be enough to see if the 2nd card is active or not.

 

[Solarstarshines]

Hmmm well I have had some Crossfire issues where my cards have done the same but .....

When I am in Crossfire it Disables itself because card #2 can't keep up with card one

are these the same makes of cards running at the same speeds because in Tandem there not supposed to get that hot

I hate to say but above information is false the main GPU does most of the load but with Crossfire it's about 60% main GPU and 40 % the other GPU which top temps if any should be getting 70c to 80c max

that is normal especially in demanding games if you really want to see if crossfire is working correctly check the CCC if it is still enabled when it isn't or Disabled itself it will tell you straight up

My main GPU by itself under Heavy load reaches 72c max and I am running a single reference card right now and I assume yours has after market cooling so I would assume it is the game settings also it would help to keep V-sync on it helps the temps and stops your GPU's from going crazy because I bet that is what the issue is turn on V-sync

 

[Apprentrice5]

Thanks for the responses, the cards are identical makes and model - i will check speeds when im home tonight

XFX AMD Radeon HD 7950 DD 3GB GDDR5 | FX-795A-TDJC

The above link is the cards that i have.

I did think it was a bit hot

 

[Solarstarshines]

Check the speeds also if the main GPU is clocked higher it will take the speed of the lesser forcing it to downclock take that in mind too