What slots in an Omen by HP Obelisk 875-1xxx are used for dual channel with 2 DDRS?

[Prométhée]

https://h30434.www3.hp.com/t5/Desktop-Hardware-and-Upgrade-Questions/What-slots-in-an-Omen-by-HP-Obe...

OMEN by HP 875-1000 Obelisk Desktop PC (5MU99AV)

so give

https://support.hp.com/us-en/product/omen-by-hp-obelisk-desktop-pc-875-0000a/23302709/model/23302710...

875-1040st CTO Product Specifications and Configurable Options

Shire motherboard specifications.

it is therefore based on the reference given by the user
If there is an error, we can wait for @smayner  to indicate the reference of the computer, and of its motherboard
not the right motherboard either
He is mentioned
HP Obelisk 875-1xxx

which gives as result

https://support.hp.com/us-en/product/omen-by-hp-obelisk-desktop-pc-875-0000a/23302709/product-info

motherboard specifications, Edoras

2x red

motherboard specifications, Erica2

2x ( certainly black ) not  4  

motherboard specifications, Moria

2x red

 motherboard specifications, Moria2

2x red

Ok not this ?

so this

https://support.hp.com/us-en/product/omen-by-hp-obelisk-desktop-pc-875-1000i/25644598/product-info

 motherboard specifications, Edoras

2 x red

 motherboard specifications, Shire

4x red

So yes, unless there is an error somewhere
the image is not given at random

@smayner  sorry, for that, but if you could at least confirm your model it might already be that!

[smayner]

Thank you, this is very helpful. This is exactly the same motherboard I have. The picture makes it very clear. Just to confirm, with this configuration in your machine, it is running in dual channel mode?

[smayner]

Actually it is exactly the motherboard I have, with four red slots.

[smayner]

You are correct. All four slots are red, just like the picture you posted, which was very helpful.  I'm assuming that with the DDRS modules in slots 1 and 3 as you show in your picture, the machine runs in dual channel mode, yes?

[Prométhée]

So to make it clear
the computer is that of another user, I gave the links, normally of the model, because it would therefore be originally configured like this
I have a completely different model
it's in dual Chanel, it's the gif image, which I indicated, it was good for the example, because it still has nothing to do, older computer
After that it's just a small test to be carried out anyway, if it doesn't work you will just have to modify the locations

Sorry, for exchanges with @itsmyname 
but I wanted to make it very clear!

[smayner]

That's fine. I can't think of any reason why they would have put the modules in slots 1 and 3 other than running them in dual channel mode, so that's what I'll start with. Thanks for the help, the picture of an actual installation of my exact motherboard with two modules installed was the confirmation I needed. 

NOTE TO ANYONE FROM HP MONITORING THIS THREAD: None of this back and forth would have been necessary if the documentation you provide could be more clear! Simple instructions in the memory upgrade dropdown on the webpage showing the specs of this board to clarify this very upgrade scenario would not be hard to do.