Hey everyone! I've got a Seasonic TX-1300 ATX 3.1 power supply that can handle up to 1300W. My current setup includes a GPU with a 600W rating, and when I add in the other components, I'm looking at a total power draw of around 800W to 900W right now. I'm planning to add a second GPU rated at 300W, which would bring the total closer to 1100W to 1200W. This leaves me with about 100W to 200W of headroom. I'll primarily be using this for AI video generation and LLMs. I've heard about GPU transient spikes—how long do those typically last? Will my PSU be able to handle this dual GPU setup safely? ChatGPT mentioned that ATX 3.1 PSUs have excursion targets up to 2600W for very short spikes (around 100µs).
2 Answers
You're cutting it really close with 1200W on a 1300W PSU. I wouldn't push it that far. A good strategy to consider is undervolting both GPUs to maximize their efficiency; this might help bring your power usage down to about 1000W to 1100W, which feels much safer. Undervolting also helps reduce those sudden power spikes! Hope this helps!
If you're running on a 120V circuit, you'll be very close to the maximum continuous draw, which could be risky. Just to put it into perspective, that’s about the same power as a big microwave running non-stop! Make sure that's the only thing on the circuit and check that your outlet is high quality and rated properly in relation to your breaker.
I'm actually using 220V. Thanks for that important info!
Thanks for your insight! You’re right, maybe power limiting or undervolting the GPUs is the best way to go.