PCI-E MOBO slots : can a x1 GPU riser adaptor be added to x16 slot? And is their a preferred PCI-E usage order?

MagnaFarta

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Can anyone help with a simple question please? My MOBO has 5 PCI-E slots (three x1; two x16). The order on MOBO is x1, x16, x1, x1, x16 (PCI-E 1-to-5). I have 3 GPUs, all with risers. The risers connect to the MOBO by x1 adapters. 1) Can I connect risers via their x1 connectors to x16 MOBO slots? 2) What order should you use them - should it be slot #1, then #2, then #3 etc? One million thank you for any advice.
 
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Look up your motherboard. Somtimes the 1x slots are only PCIe 2.0 while the x16 are PCIe 3.0. if that is the case I would then use the x16 slots first before the 1x slots this way those two will get twice the bandwidth as the 2.0 slots. If they are all 3.0 then it will not matter what ones you use. Maybe use the 1x slots this way you have the x16 open for anything else down the road.
 

MagnaFarta

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Nice one for the info, Dr Tweak. Much appreciated. My MOBO is a MSI 970A-GAMING-PRO-CARBON (link below). Just checked its PCIe details and it says the following:

2 x PCIe 2.0 x16 slots (support x16/x0, x8/x8 mode)
3 x PCIe 2.0 x1 slots

So I guess that means they are all 2, not 3.

The reason I originally asked this question was because I am trying to troubleshoot a problem I am having with my GPUs and Display (see here: http://www.tomshardware.co.uk/answers/id-3437044/single-gpu-mining-rig-monitor-worked-fine-added-gpu-monitor-stopped-working.html). If you have any suggestions for that problem (even left field ones - I am at my wits end with it!), that would be swell! My mate mentioned something about a possible need for xfiring/using SLI cables. Isn't that for old cards, not nice new RX480s?

Also, do you know if is it ok to connect a x1 shaped connector into a x16 shaped MOBO slot?


https://www.msi.com/Motherboard/970A-GAMING-PRO-CARBON.html#hero-overview
 


Hmmm. I have not dont a mining machine before let alone plug in a video card into a 1x slot or multiple of them at that so I am not sure. I am also not familiar with Ethos as the OS so I wouldn't even know where to begin. Does the screen get detected on POST at all?

As far as plugging a 1x into a 16x that is perfectly fine. PCIe is all backwards and forwards compatible and between different lane amounts unless noted by the card (I know some 10GB Nic cards REQUIRE a 4x or 8x PCIe slot and will not work in a 1x slot) but most graphics card will work in a 1x just fine as everyone does it. I also had used a USB3.0 x1 card in my x16 without issue.
 
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MagnaFarta

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Thanks again for shedding further light on my follow up question - much appreciated. After several further technical issues, it turns out my MOBO is dead, so I am currently arranging RMA....