What will happen if I installed a graphic card in a PCIEX16 slot, running at x4 ?

[eis3nheim]

I am planning to buy Gigabyte motherboard GA-970-Gaming and it has one PCI Express x16 slot, running at x16 and the other one PCI Express x16 slot, running at x4.
And I have got two graphic cards:
1. Radeon HD 6870
2. nVidia GT 520
I want to install the Radeon HD 6870 on the PCI Express x16 slot, running at x16 and the GT 520 on the PCI Express x16 slot, running at x4, so will the performance of the GT 520 drop, and could it cause damage to it over time.

 

[goldstone77]

Is it in PCI-E slot 1 the 16X slot? Have you tried going into the Bios and changing it?
https://www.gigabyte.com/Motherboard/GA-970-Gaming-rev-10#support-manual
Expansion Slots Š 1 x PCI Express x16 slot, running at x16 (PCIEX16)
* For optimum performance, if only one PCI Express graphics card is to be installed,
be sure to install it in the PCIEX16 slot.
Š 1 x PCI Express x16 slot, running at x4 (PCIEX4)
* The PCIEX4 slot shares bandwidth with the M2F_10G connector. The PCIEX4 slot will
operate at up to x2 mode when a PCIe SSD is installed in the M2F_10G connector.
Š 2 x PCI Express x1 slots
(All of the PCI Express slots conform to PCI Express 2.0 standard.)

 

[goldstone77]

Wait you are I'm sorry I miss understood what you were asking. You want to run 2 different cards at the same time. You could install both of them, but if it did there would not be any benefit. It might actually end up making your performance worst. Are you trying dedicate the Nvidia card to run Physx?

 

[eis3nheim]

I am trying to increase the overall graphical power, for example installing multiple screens.
And really thanks for the answer.

 

[clarkjd]

Why do you want to run two different video cards? You can't crossfire them or SLI them as they are two different GPUs.(one AMD and the other nVidia).

 

[goldstone77]

I am trying to increase the overall graphical power, for example installing multiple screens.
And really thanks for the answer.

You won't get the benefit you want. If you have 2 of the same card running in SLI or Crossfire you get about 25% extra performance running16x16 or 8x8. The performance difference in 8x and 16x is less than 1%. 4x isn't worth it even if you had the same video cards. better off just using the 6870.
http://www.tomshardware.com/reviews/gpu-hierarchy,4388.html

 

[kraelic]

It won't increase the graphical power. Nvidia drivers will detect and disable PhysX when it detects an AMD card. You can use it to display to an extra monitor. 4x lanes are plenty to feed a GT 520. No harm, not much FPS loss at that level.
https://www.youtube.com/watch?v=rSfifE2Domo

 

[maxalge]

I am planning to buy Gigabyte motherboard GA-970-Gaming and it has one PCI Express x16 slot, running at x16 and the other one PCI Express x16 slot, running at x4.
And I have got two graphic cards:
1. Radeon HD 6870
2. nVidia GT 520
I want to install the Radeon HD 6870 on the PCI Express x16 slot, running at x16 and the GT 520 on the PCI Express x16 slot, running at x4, so will the performance of the GT 520 drop, and could it cause damage to it over time.

1. dont buy an am3 setup, go either ryzen or intel

2. no benefit to running those two cards together