How many case screws are required for an ATX motherboard?

[Marshen]

I recently purchased a MSI B450 Tomahawk motherboard alongside the ryzen 5 3600 processor and I was wondering how many screws do I need for the motherboard to sit firmly on the case. The motherboard has 9 screw positions but currently I only have around 6 because my previous motherboard was m-atx. Will that be enough? Also which slots are the most important to prevent and flexing?

I'll be using a ROG STRIX GTX 1060 6GB as well as the stock amd stealth cooler for the processor. 

[TVwazhere]

12 minutes ago, Marshen said:

 The motherboard has 9 screw positions but currently I only have around 6 because my previous motherboard was m-atx. Will that be enough?

Your case comes with the necessary screw to install ATX motherboards, assuming it's an ATX case. So if you have an ATX case, you should have 9 motherboard screws.

 

PCi-E slot flexing isnt really a factor in determining which PCI-E slot to choose. It's always recommended to go for the top most available slot for best results since boards will give that slot the most PCI-E lanes (x16)

[SupaKomputa]

one in all corners and 2 in the middle should be fine.

the most important slot is the gpu slot (x16).

[Marshen]

14 minutes ago, TVwazhere said:

Your case comes with the necessary screw to install ATX motherboards, assuming it's an ATX case. So if you have an ATX case, you should have 9 motherboard screws.

 

PCi-E slot flexing isnt really a factor in determining which PCI-E slot to choose. It's always recommended to go for the top most available slot for best results since boards will give that slot the most PCI-E lanes (x16)

I'm using the same case as before which i had bought in 2016. It is an atx case but i don't have the additional screws with me anymore. 

[TVwazhere]

1 minute ago, Marshen said:

I'm using the same case as before which i had bought in 2016. It is an atx case but i don't have the additional screws with me anymore. 

In that case I would do all four corners, the very center stand off (if it isnt a raised nub) and then the last screw to the left of the center standoff. 

[mariushm]

You can put none. You can buy nylon standoffs with hooks at the top like this if you really want to:

 

 

You want to use standoffs and screws in the locations where you want to prevent the motherboard from flexing (bending) too much.

It's a good idea to have a screw by the corner near the IO shield, so that when you insert connectors in the IO shield, the motherboard won't move.

It's a good idea to have a screw in the middle, close to the pci-e connector, with the proper standoff under the board, so that when you insert a video card, the board won't bend in the middle.

It's a good idea to have a screw near the 24pin power connector, because when you insert that connector into the motherboard, it takes a bit of downwards pressure so if there's no standoff under the board near tht connector, the board would bend.

The rest are usually less critical, for example the bottom corners, because you usually don't fill all the board with cards to put weight on the motherboard, and on the other corner there's only front panel header and sata connectors so again not much downwards pressure to cause flexing.