I'm upgrading my Omen 40L, 3070 GPU to a 4070...

[RockawayBrian]

I have a similar issue as MarkP316, upgrading my 3070 GPU to a 4070. Here are my issues/questions: I currently have a GeForce nvidia 3070, but am installing an MSI 4070. My computer is an Omen 40L OMEN by HP 40L Gaming Desktop PC GT21-0000a (514R7AV). Is that MSI GPU compatible? What, exactly, should I do prior, as in uninstalling the 3070/Nvidia drivers? Does this type of upgrade void my warranty? Lastly, I have an Omen 30L, Ryzen 5 3600 with a 1660 Super. Can I take this outgoing 3070 card and throw it in as an upgrade for the GTX 1660 Super? Thank you!!!

[BeemerBiker]

The 4070 is an improvement over the 3070

Both boards have the same recommended 550 watt power supply and the 4070 uses slightly less power

https://www.techpowerup.com/gpu-specs/hp-rtx-3070-oem.b8574

https://www.techpowerup.com/gpu-specs/msi-rtx-4070-gaming-x-trio.b11051

I see two problems.  According to TPU (above link) the HP uses a 12 pin connector but the 4070 is 16 pin,.

In addition it is likely (I am guessing) the HP board is a pusher and pushes the air out of the case while the MSI has 3 fans that essentially stir the hot air around in the case and assumes the case fan is good enough to get all the hot air out. 

You may have to leave the side off or put up with a much louder system due to fans running at %100

See if you can get a pusher type 4070 especially if it has 12 pin connector instead of 16.

Ignore the above hot air problem if the HP board is like the MSI.

AFAICT there should be no problem with the warranty

 https://h30434.www3.hp.com/t5/Desktop-Hardware-and-Upgrade-Questions/Upgrade-Video-Card-void-my-warr...

The only problem I have ever seen is replacing fans on a video board with hybrid liquid cooling.  The old cooler needs to be put back on before returning for warranty

[RockawayBrian]

Wow, thank you for the detailed and thoughtful reply! So, I have it installed and am using it right now.  Yes, my old GPU had a 12 pin set up, which consisted of two 8 pin cords (P.9 and P.10) being merged together thru an adapted cord, turning the two four pin plugs into one 12 pin. This 4070 has just one, 4 pin plug. The only solution seemed to be unplug the 12 pin adapter, and just use one of the 4 pin plugs (I chose the P.9) and plugged that into the 4070 GPU. It's working, but am I totally missing something, or inadvertently cutting the power supply in half? Again, it is working right now, seems like everything's good. HP Support assistant did some basic video tests, all passed. 

Anyway, thank you again for the very quick and thoughtful reply. 

Brian