Asus Crosshair VIII Hero, M.2 Install?

daphatgrant

Fi-yah!
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Which M.2 slot am I supposed to use? Does it not matter? I'm not seeing a specification in the manual.

m2.PNG
 
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mda

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Based on the text in the manual:

The top slot uses PCIE lanes from the CPU. You should be using that first, as it is theoretically faster due to less overhead.

The bottom slot uses PCIE lanes from the X570 chipset (see 3rd bullet point).

Not sure on the actual/real-world speed differences between the two slots though! I'll guess that there isn't a big difference either way.
 
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Mar 23, 2013
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Unless the bottom slot is somehow hampered (doubt it), I'd use that over the top slot between the video card and CPU. More room to breath lower down on the board. That's just my opinion as I'm sure the real world difference wouldn't be noticeable.
 

thesmokingman

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In general, the closes slot to CPU are primary slots. This goes for the m2 and gpu slots.
 

OliverQueen

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Buy 2 drives & populate both ports. No need to worry about which one to use then. You will always use more storage!
 

bradk674

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Nov 7, 2020
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I know this is an old thread but I have a similar question. I have a Crosshair VIII Hero Wifi and I currently have a Sabertooth PCIE 4.0 1 TB NVME installed in the M.2 slot closest to the CPU. I plan on upgrading to a Ryzen 5900X as well as a RTX 3080. If I add a 2nd NVME in the other M.2 slot weather PCIE 3.0 or 4.0, will it affect the bandwidth of the GPU, meaning will it run at full speed X16? Will PCIE lanes be affected?
 

vegeta535

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I know this is an old thread but I have a similar question. I have a Crosshair VIII Hero Wifi and I currently have a Sabertooth PCIE 4.0 1 TB NVME installed in the M.2 slot closest to the CPU. I plan on upgrading to a Ryzen 5900X as well as a RTX 3080. If I add a 2nd NVME in the other M.2 slot weather PCIE 3.0 or 4.0, will it affect the bandwidth of the GPU, meaning will it run at full speed X16? Will PCIE lanes be affected?
It shouldn't effect your gpu. It might disable some SATA ports tho. You have 20 lanes direct to the cpu so you will get 4 for the main m.2 and 16 for your gpu. The other slot uses 4 lanes that is shared with all the interconnects.
 
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