GPU for PCIe 2.0 x4

[stevenevents]

My motherboard has a PCIe 3.0 x16 slot, and a 2.0 x16 slot (running at x4.)
At present, I have 2 (of 4) CPU folding, in addition to the GT 1030, and my APU's Radeon R7.

From what I can see, the 2.0 x4 port will bottleneck any other card (GT 600, 700 series) that I have. If I add a card to the 2.0 x4 slot, then I'll have one CPU folding, and the other three supporting the other three GPU.

Is there any card worth using for FaH on this second port?

[jrweiss]

If you can find a 1050 or 1050ti for a reasonable price, it should serve well - low power draw and reasonable performance.

[HaloJones]

It might bottleneck a card in Windows but in Linux there is no problem with slower slots. I have a TitanX running off an x4 slot and the slot utilisation shows as around 55%.

Personally I'd move the 1030 to the second slot and get a used 1070 in the x16 slot

[stevenevents]

Your suggestion is a likely option, HaloJones, though I'll be sticking with Windows, as a lack of AMD support, for the Kaveri APU on Linux, means that I won't have the proprietary driver to utilize the R7. Thanks for your responses.

[MeeLee]

My experience with ddr3 motherboards and pcie 2.0 slots, is that their bioses often aren't updated for modern GPUs.
That being said, I think that you could put anything up to a GTX 1660ti or 1660Super. Faster (RTX GPUs) might not be compatible with the bios, or if they do, their performance won't be much higher than those GTX GPUs.
However if you want to play safe, the GPU that is fastest, that works on older motherboards, is the GTX 1060 (6GB).
It's the fastest you with wide BIOS compatibility.
I don't know much about bios compatibility with newer AMD GPUs.
A more modern AMD GPU, if it works, might be a better option than an older 1060

[bruce]

You've gotten some really good suggestions. Now you have to survey the market and make a choice. By all means put the GT1030 in the 4x slot. It's a slow GPU and will not be limited by being in a 4x slot. Any of the GPU suggestions above could go in the 16x slot.

I would probably ignore the Kaveri APU for FAH. The iGPU processing competes with CPU processing so using it for anything except displaying the desktop will slow down the CPU slot that you intend to use. In many systems, the BIOS prohibites the concurrent use of the APU for display purposes when your system also includes a dGPU. Is your monitor running from the motherboard connector or from the connector on the GPU?