HD7970 X 2

[bagachi]

Hi,

Just finished a production with a new machine which has the follow configuration:

OS: Window 7 Ultimate 64bit
Mother Board: Gigabyte x79 UP-4
CPU: Intel i7-3930K / 6 Core/ 3.2 GHZ
RAM: 4 X 8 GB DDR3-1600MHZ
Harddisk: Plextor PX-256M5P SSD
Graphics: Sapphire HD7970 Vapor-X 6G (Connected to Three TH2GO, Two DP, One Digital. The port left are for Control)

The original plan is to have 12 outputs instead of 9 outputs from this new machine. However, despite having 5 outputs, the Sapphire Card failed to activate all 5 outputs when I connect 4 TH2GO (Two DP, One Digital, One Analog) to the card. So I could either have 12 outputs with no control view, or 9 outputs with control.

Coz I've missed out the MSI R7970 Lightning and ASUS HD7970 DC2T, and it takes too long for the local supplier to get these cards for me, I bought another Sapphire HD7970 Vapor-X 3G card, hoping that could expand the numbers of output.

I've learn from the forum that two cards setup would not work most of the time. That's true for my case too. At first whenever I powered up the second card (3G Ram one), Arena's fps (without loading any content) will drop to below 3fps. Later when I update the graphic driver to 12.10, I could finally display at the second card . But it is still impossible to display on both card at the same time. CrossFire just wouldn't work whatever the driver version.

Just wonder if any of you guys have a similar experience of having two HD7970 in one system. Thanks!

[HerrNieDa]

first, crossfire is not supported... just did some tests with sli and got the half of framerate with sli activated!

second, analog matrox triple/dualhead 2go (vga edition) has no multi unit-support, so if you wan't to use multiple tripleheads, you can't use the analog ones

i tested (with 1 output-screen) the performance with nvidia and there is no difference if i use the main or the second graphic card! (with ati i must say i had other experiences, but not that i got 3fps or so, maybe -33% performance loss, but can't say it exactly, too long ago that i used an ati system with more than 1 graphiccard for multiscreen).

for better performance with multiscreen-setups on ati cards you should activate eyefinity to get less extra screens in windows (which seems to be a problem at least on windows, tried with 9 monitors on a 6970 and got better performance as i switched the resolutionn of the screens from 1024x768 to 640x480, nvidia setups don't have this problem!)..

hope this information helps you

[cosmowe]

the Sapphire Card failed to activate all 5 outputs when I connect 4 TH2GO

are you using activ displayport adapters?