So I know this is a very hot topic here on the forum. How much power does a 980 card draw??....
I have a mac pro hex core (3.46) with both OSX and windows on it. Recently upgraded my GTX680 to a GTX 980ti FTW. I have access to a regular 980ti that I use on a work machine and thought it would be a good comparison to see what each one draws. I used iStat monitor to watch amp draw and then converted those numbers to watts pulled. This is probably not the most accurate method, but it at least gives information as to what is going on.
First, the 980ti. This card is both a 6 pin and a 8 pin, rated at 250w max. I used an 8 pin adapter and both power leads are being pulled from the logic board. This card has been connected and running this way (on work computer) for the past year and a half with no trouble. I used Unigine Valley for the test load. Ultra settings at 2560x1600.
PCI = 50.4 watts
Boost 2 = 56.4 watts
Boost 1 = 94.8 watts.
total: 201.6 watts
As you can see boost 1 pulls a massive amount of power, well over the rated spec of 75w. The load certainly is not balanced. Card or computer does not run hot, no artifacts or problems. I have had one shutdown in windows and I attribute that to boost 1 pulling over 100w and the power supply just shut off. Card is not reaching the 250w max and not sure what you could do to reach that. maybe 4k?
980ti FTW. This card has 2, 8-pin connectors and is rated at 275w max. After seeing the results of the first card, I decided to hook this up with extra power. I used an 8-pin to SATA Y-adapter and ran that off both leads in the optical drive bay. I then used the two booster PCI leads and joined them with a 6-pin to 8-pin Y adapter. The results are interesting. Loaded up Unigine valley at the same Ultra 2560x1600 settings.
PCI = 51.12 watts
Boost 2 = 51 watts
Boost 1 = 38.4 watts
Optical = 31.92 watts
total: 172.44 watts
The FTW card has a much higher clock speed and higher max power, but pulled considerably less power. I was surprised. settings were the same, FPS results were the same. Power across the machine was being pulled in a more reasonable manner and well within the specs of the connections
It's interesting to see that the PCI slot does not pull 75w as rated and hovers around the 50w mark.
Now, iStat monitor could be full of crap and these readings way off. If that is the case, who knows what this thing is doing. Either way, both setups work, just that the first pulling that much power from the board is somewhat unreliable. It seems that the power supply protection switches the machine off before something bad happens to the board.
I wish there was an app in windows that showed amp draw like iStat. That would be a helpful test to run. So far, have not found one that reads the mac sensors.
I have a mac pro hex core (3.46) with both OSX and windows on it. Recently upgraded my GTX680 to a GTX 980ti FTW. I have access to a regular 980ti that I use on a work machine and thought it would be a good comparison to see what each one draws. I used iStat monitor to watch amp draw and then converted those numbers to watts pulled. This is probably not the most accurate method, but it at least gives information as to what is going on.
First, the 980ti. This card is both a 6 pin and a 8 pin, rated at 250w max. I used an 8 pin adapter and both power leads are being pulled from the logic board. This card has been connected and running this way (on work computer) for the past year and a half with no trouble. I used Unigine Valley for the test load. Ultra settings at 2560x1600.
PCI = 50.4 watts
Boost 2 = 56.4 watts
Boost 1 = 94.8 watts.
total: 201.6 watts
As you can see boost 1 pulls a massive amount of power, well over the rated spec of 75w. The load certainly is not balanced. Card or computer does not run hot, no artifacts or problems. I have had one shutdown in windows and I attribute that to boost 1 pulling over 100w and the power supply just shut off. Card is not reaching the 250w max and not sure what you could do to reach that. maybe 4k?
980ti FTW. This card has 2, 8-pin connectors and is rated at 275w max. After seeing the results of the first card, I decided to hook this up with extra power. I used an 8-pin to SATA Y-adapter and ran that off both leads in the optical drive bay. I then used the two booster PCI leads and joined them with a 6-pin to 8-pin Y adapter. The results are interesting. Loaded up Unigine valley at the same Ultra 2560x1600 settings.
PCI = 51.12 watts
Boost 2 = 51 watts
Boost 1 = 38.4 watts
Optical = 31.92 watts
total: 172.44 watts
The FTW card has a much higher clock speed and higher max power, but pulled considerably less power. I was surprised. settings were the same, FPS results were the same. Power across the machine was being pulled in a more reasonable manner and well within the specs of the connections
It's interesting to see that the PCI slot does not pull 75w as rated and hovers around the 50w mark.
Now, iStat monitor could be full of crap and these readings way off. If that is the case, who knows what this thing is doing. Either way, both setups work, just that the first pulling that much power from the board is somewhat unreliable. It seems that the power supply protection switches the machine off before something bad happens to the board.
I wish there was an app in windows that showed amp draw like iStat. That would be a helpful test to run. So far, have not found one that reads the mac sensors.