You know what it is don`t you.
What you may be seeing, is the on board graphics solution of the motherboard or the I7 Gpu.
The cause.
Go into the bios of your motherboard make sure you manually select Pci-e as the interface mode for the Pci-e graphics card slot of the motherboard.
If you have the option in the bios to disable the Intel graphics solution do so.
Check that the eight pin E-ATX power block to the motherboard is connected via your PSU.
And that you have fitted, and connected any required 12v Pci-e power connectors required from the PSU direct to the GTX 970 card.
If the system had any other form of graphics card in it, for example something from AMD or ATI.
You should remove the graphics driver for that card from the system before you put the Nvidia 970 GTX card in the system.
And if the option to disable the Intel graphics solution in the bios is also disabled or turned off.
Remove the driver for the Intel graphics solution if setup and detected by windows.
Restart the system once done.
Download the latest Nvidia graphics driver and install on the system.
Restart the system again.
Then test with the Heaven benchmark suite.
Post back, let us know if the problem is resolved sirstubbs