Vmix recommends to use cpu lanes for gpu and capture card
but many people use chipset lanes without knowing it and it still works, even if it is always better that it is managed by the cpu directly, it avoids the "back and forth" and the "tolls" between chipset and cpu, I extrapolate to illustrate my words
you just have to be careful not to exceed the maximum bandwidth of the chipset
taking into account that the bandwidth of the chipset is shared with other peripherals (lan/wifi, usb ports, sata III ports)
and that some slots/ports can be disabled relative to each other because they share the same bandwidth in the chipset.
you have to consult the motherboard manual.
unlike the micro atx b550, some atx am4 like the Asus proart B550 creator for example, are able to divide the 2 pcie slots managed by the cpu
and allow to have the cpu lanes on more slots (pcie or m2)
Ryzen 7 5800x (= 20 cpu lanes) on Asus proart B550 creator
E17757_ProArt_B550-CREATOR_UM_WEB-1.png
(81kb) downloaded 1 time(s).A + M2_1 = x20 cpu lanes
default configuration:
pcie slot 1 = x16 = gpu
m2_1 = x4 = windows ssd
split configuration:
pcie slot 1 = x8 = gpu
pcie slot 2 = x8 = duo 2
m2_1 = x4 = windows ssd
in configuration 2, we can even install a decklink quad 2 (pcie 2.0 x8) instead of decklink duo 2 to have 8 x sdi inputs/outputs
B + C = B550 chipset = one device used disable another or reduce bandwidth of all
b550 split.jpg
(30kb) downloaded 1 time(s).for config, put 2 x16 gb ddr4 to be quiet
see if with the gtx 1060 there are no problems
otherwise upgrade for gpu rtx 3000/4000
for more bandwidth on the chipset, opt for a motherboard with x570 chipset (pcie 4.0 x4)
Given the components already in your possession, if you opt for an ATX motherboard, I advise you to take the Asus proart x570 creator.
it allows to have a 2nd M2 port managed by the cpu, by lowering the pcie 2 slot to x4 instead of x8
configuration 3:
pcie slot 1 = gpu = x8
pcie slot 2 = duo 2 = x4
M2_1 = x4
M2_2 = x4 (for a second ssd or a 2nd decklink duo 2 via m2 / pcie x4 adapter)
E19234_ProArt_X570-CREATOR_WIFI_UM_V2_WEB_page-0001.jpg
(250kb) downloaded 0 time(s).and a 4.0 x4 chipset bandwidth to be able to use the thunderbolt 4 ports (=pcie 3.0 x4) +/or the pcie 3 slot or the M2_3 port, etc....