Been building up a folding rig server.
I have 1 MSI GTX 1050 4 gb
&
2 Asus GTX 1050 2gb
 
When I add another GTX 1050 2 gb, my folding software keeps downloading and sending WU´s. It impacts 2 graphic cards.
When I remove the graphic card. Everything works great.
Been updating the drivers, I even tested the graphic card on a different computer ( Works Great ), I could play eve online, I can even fold on my computer, but it wont start to fold on my server.
Windows 10 Pro is fully updated.
 
Any tip how to solve this?

I was suspecting that, but I have an Intel I5 gen6 cpu with 4 cores, it should work with 1 core per graphic card.
My motherboard (H110 pro btc+) supports Intel gen 6 & 7.
How ever, when the jobs are received & the 3 graphic cards are working, the cpu usage is nearly 90 % more or less.
 
No Linux & No mac for me, just windows.

Which cpu can handle 6 graphic cards.
My motherboard supports Intel gen6 & gen7.
The highest I found is Intel Core i7-7700k, which also has 4 cores, but I have 5 graphic cards in total & my server starts to fail when I add Card nr 4.
Will this Intel I7-7700k solve my problem?
 
 

With Windows, a LOT of the time, any time you add a video card, it changes the order of how the cards are detected by the OS so a card that was once assigned the O slot is suddenly in the 2 slot.

This means that Folding is expecting a specific card in that slot and not seeing it because the configuration is pointing to the old setup.

The best thing to do, esp in Windows, is ANY time you add a card, erase all the slots and begin the configuration from scratch.

Also, if you're folding with DIFFERING cards, you should look up this guide to ensure you have the correct info in each slot:  https://www.overclock.net/forum/366-folding-home-guides-tutorials/1490720-guide-configuring-client-v7-7-4-4-multiple-additional-gpus.html
 
They have changed the layout of their boards so the images were broken the last time I looked at it, but the text should give you enough information to collect the data points you need.
d

I guess I missed to investigate that.
So this server can be an effective mining server, but not a folding server.
 
Which motherboard should I have purchased?, just curiosity.

Can Linux solve my problems, so I can use 6 or 8 graphic cards? or do I need a different motherboard as well?

My motherboard (H110 pro btc+) supports Intel gen 6 & 7.
Slightly hidden in the first post. It's one if the bitcoin mining motherboards with 1 x16 slot and 12 x1 slots for extension cables. So I'm assuming it's a single x8 wired slot and the rest are x1 from CPU and chipset.

As everyone's saying, your motherboard's PCIe limitations are rearing their head. If you're adamant about having 3-4 cards in use on the same rig, you're going to need to upgrade to a board with 4 slots that will run concurrently (8/4/4/4): https://www.newegg.com/p/N82E16813130870
 

You could snag up that x58 eVGA Classy 4x sli combo in the fs section. I still have one with 3 1060s on it and she rocks out. I did not read what cards you are running so that could be an issue but probably not. Load Mint or ubuntu and let it rip.
 
I have a mining board that I picked up cheap and tested those cards folding on it and it was horrendously poor. However on seti it was gr8. Other crunching projects may do well but I did not check. 

Great information from all, but will a CPU upgrade help my folding system to work.
I have 3 x gtx 1050 ti & 3 x gtx 1050 graphic cards.
When mining, it works great, but when folding. only 3 can fold.
So if I upgrade my cpu I5 gen6 to I7 Gen7, will it support my other graphic cards or will it fail?

For a 1050, you can use 1 core per 2 gpus, IF your cpu is 3Ghz or more. The 1050 load on a cpu is somewhere like a 1.5Ghz at full load.

I tried pcie x1 to 4x x1, and those units didn't work very well at all. I also bought a rather expensive x16 to 4x x4 m.2 slots, and also that didn't work with my motherboard.

Third, older intel motherboards limit the amount of Nvidia GPUs to 4 (if you're lucky). More modern 6th gen or up intel motherboards limit it to 3 GPUs, and my current 9th gen intel mother board limits it to 2 GPUs (if I add a third, even if I set the slots to x4+x4+x4, or x8+x4+x4 or x8+x8+x1, I just get a blank screen.
And I tried a lot of Intel motherboards.
Your best bet would be with AMD B500 series motherboards, simply because i haven't tried them yet.
Nvidia is discontinuing SLI support, and theres a chance in the near future, motherboards will only support no more than 1 dGPU.
Then again, the RTX 3090 is something you don't actually want to run too many of in a pc, as they draw almost 400Wof power.

Mining boards with multiple x1 slots usually are PCIE 2.0 speed. They're only fast enough for GT 1030 gpus, and come on motherboard supporting 2 cores, with 4 threads at best. (4c/8t cpus for them are expensive)