Does a GTX 1080 fit inside a HP Prodesk 400 G3 MT

[Xealo]

Does a GTX 1080 fit inside a HP Prodesk 400 G3?

• how many watt power supply do I need for the minimum to run the GPU? 
  Can the GPU even run on the pc and doesn’t it bottleneck with the i5 6500 CPU? 

[NonSequitur777]

@Xealo,

Welcome to our HP User Forum!

Your HP ProDesk 400 G3 MT is either fitted with a 180-watt or a 300-watt power supply, whereas a GTX 1080 requires a 500-watt power supply plus one 8-pin PCIe power cable.

Fortuitously, your motherboard is 24-pin ATX-power enabled, meaning, you can easily swap out your current power supply with any industry standard ATX power supply, as long as you watch its dimensions (LxWxH) for fit inside your case.

When it comes to what GTX 1080 graphics card has the best chance to fit on your motherboard, as the picture above tries to illustrate, large-sized graphics cards may not be suitable given that the PCIe x16 slot is situated in such a way that your RAM slots and motherboard connectors may be in your GPU's way.

If you have set your heart on a GTX 1080, probably a smaller sized card would be preferable, such as: ZOTAC GTX 1080 Mini Specs | TechPowerUp GPU Database.

An i5-6500 would be fine and wouldn't bottleneck anything.  However, if you are interested in pairing a GTX 1080 with a better performing processor, I would strongly recommend upgrading your processor to an i7-6700K.

Hope this was helpful.

Kind Regards,

NonSequitur777