Installed a second GPU and machine won't boot

[AvaGardner83]

Hi there,
I installed a second GPU (Sapphire Radeon Nitro + RX 580 8GB GDDR5 Dual HDMI DVI), but the machine won't boot when it's connected.
Sorry if this is an obvious question...am I missing something?

Thanks in advance for your help

 

[Jamesbond007]

Hi there,
I installed a second GPU (Sapphire Radeon Nitro + RX 580 8GB GDDR5 Dual HDMI DVI), but the machine won't boot when it's connected.
Sorry if this is an obvious question...am I missing something?

Thanks in advance for your help

May I ask why you want to install this second card instead of replacing the present card with this card?

Did you connect the PCIe power cables from the power supply to the card?

 

[AvaGardner83]

May I ask why you want to install this second card instead of replacing the present card with this card?

Did you connect the PCIe power cables from the power supply to the card?

Hi, thanks for the reply.
I'm trying to upgrade this machine so I can use it for 360 projection, I need to connect 6 projectors.
Yes, I connected power, but I realised the problem might be that my power supply isn't strong enough (it's a 650w).
I ordered an 850w one, maybe that will do the trick.