Building first GPU rig - Can I mix RTX 3080 cards?

Hey there,

I’m trying to acquire some RTX 3080 cards to start building my first rig. I’ve already secured 2 of the MSI RTX 3080 Ventus 3X 10G OC cards. Now I’m looking at one by EVGA. Does anyone know if I will have issues trying to mix like that (or with the other versions like FE etc)? I know we can’t mix different models, but is my case different?

You should be able to mix cards. I would be more worried about your place being able to handle the power that those cards put out since this is your first build :flushed:

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Can you elaborate? I know I will need 200 - 240 Vac for some rigs, and that I can do.

Referring to the TDP of the cards… each one needs I think 225-250w per card with the right undervolt settings, so you have to make sure it’s on a circuit with enough amps to run it.

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Ok thanks. Is that something that typical households in US can’t supply? I could always install a new and higher amperage circuit breaker in my panel if needed.

It’s more along the lines of “what else is on the circuit” question than anything else. I had the capability of adding a new 20A breaker on mine to run a miner and some other stuff. If you don’t, I’d suggest figuring out what the power draw is on the miner you want to build is going to be, see how many amps that takes, and plugging it into an outlet that doesn’t have much else connected.

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Nice. Thanks for your help. Yeah I am still deciding on if I should DIY it or get something like a Minderdude. I just haven’t done the math to see what all the parts, materials, hardware, etc. will cost vs just buying something ready to go. Being that this is my first, I’m leaning towards a prebuilt.

As for the circuit, I haven’t done the research yet to see if there’s something I can buy to make it run off a wall outlet, but if not I guess I will be doing what you did and add a breaker.

Now…where to put this loud beast?!?

I had a shed I kept mine in. If you’re in an apartment or rental, the best place would be near a window so you can vent the hot air out. Otherwise, you’ll be getting toasty. DIY isn’t too bad. I struggled for the first two weeks or so finding the right settings and stuff, but nVidia cards are pretty straightforward and don’t require bios mods or anything, just overclock and undervolt tweaks that you can find video guides for days on. If you do decide on diy, I’d suggest closed case for ease of venting airflow, but depending on your budget, open frames are also ok. Check out listings for the cases with the Oonda motherboard with prebuilt in cpu and ram, then get you the GPUs, psu, and load up a mining software and go.

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Thanks. That was my next question…if I could put this thing in my garage. Now, being it’s cold, it would be ideal. But summer time in SC is HOT! Humid and hot. So I was going to ask if you think that would work or would it overheat the GPUs?

Airflow is key… for a southern summer, you may way A/C in the room and still have a window with a fan to pull the hot air out.

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A 15 Amp with continuous load should not supply more tha 80% of its 1800 Watt capacity at 120 VAC. A Power Supply should not supply more that 80% of rated load if run continuously.

Also, there are only 6 pcie connectors on most 1200-1300 watt power supplies so it looks like you will need two POWER SUPPLIES. If you run 80% capacity on two power supplies whose wattage total 1800 Watts or less, you will not trip the breaker provided nothing else is on the circuit. If your total power supply wattage is greater than 1800 watts, then the maximum draw from the breaker should not exceed 80% or 1800 watts, or 1440 watts. For a 20 Amp circuit, the values not to exceed are 80% of 2400 watts or 1920 watts. For total power supply wattage less than 1800 watts, the maximum wattage will be 80% of the total wattage of the power supplies with a balanced load and nothing else on the circuit.

Things to consider are that the connections to the receptacles should be tight from the breaker forward thru each receptacle to the load. Extension cords and power strips need to have heavy wiring too, as many cheap ones use 18 gauge wire and will fail resulting in burnt receptacles and plugs. Also, you can’t plug two rigs into the same circuit if you fully load it with either rig.


Thanks. I was thinking of buying a minerdude 9 GPU rig but it runs on 220 Volts. I’ve seen a few other rigs that come with PS running off 110 Votls. But for 110 volts, I did the math on the wattage and it would be slightly over 30 Amps if I fill the rig with RTX 3080 GPUs. I know it’s better to have lower amperage and higher voltage, since it will result in less heat and less power loss.

I don’t have 9 now, but I will have 3 soon otw. So to future proof this rig, I guess I’m going to need to run 220 from my panel which is not a problem, just more work than plugging into one of the existing outlets. The only bad part is the room I plan to put this rig in is upstairs so I’m going to have quite a time pulling cable there. Any additional advice is welcome.

Thanks guys.

Mix em up mix em up mix em up mix em!

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So running different model 3080s is okay. What about 3070s with 3080s?

On an all nVidia machine you can definitely mix them like that. I know people that have 1070, 1660ti and a couple 2060 super on the same rig.


Great! Thanks man!