3090 + 750w psu
prunedmusic
Posts: 0
in The Commons
I'm upgrading from a 2060 6gb. I have a corsair rm750x, and an opportunity to buy an rtx 3090 for $750
I know I should get a 850-1000w psu, but it's either the 3090 or a 12gb 3060 for $200
I'm not sure how much resources daz3d will take with 12gb, so I wanted to just get the most vram.
I keep getting mixed messages with the 3090, some say it's fine and some say it's really pushing it. I'm just not sure and the opportunity is passing.
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Comments
A 750W PSU is what Nvidia recommends as a minimum for the 3090, but the general consensus I've heard is that Nvidia's recommendations for the 30 series cards were cutting it fine.
I'm also assuming that the PSU is the same age as the rest of your system and, based on your existing GPU, probably around five years old. Bearing in mind their maximum output derates somewhat over time, I would say you're at risk of power problems.
The PSU is the backbone of your system, and really not a good place to be underspecced, as it can cause reliability problems in any number of other components. You might get away with it for some things, but not for others. (Note that Iray rendering usually does not max out a card's power draw, as the card's architecture is optimised for gaming, and Iray has different bottlenecks).
The 3090 is obviously a better card than the 3060 (although the 12GB 3060 is still a very decent Iray card if you're on a budget), but if you want it then I would definitely recommend that you look at upgrading the PSU at the same time.
I ran 3090 on a 750W Seasonic SnowSilence fine for a couple of years until I upgraded the rest of my system that adds ~50-75W (more power hungry CPU, another 32GB DRAM and 2 more NVMe sticks) and the PSU started to choke once a while. Upgraded to a 1000W PSU and no more PSU shutdowns. So 750W is probably OK if the rest of your system is not power hungry but the margin is very thin. When I was shopping for 1000W PSU Seaonic has stopped listing anything below 850W as 3090 suitable.
My 3090 FE GPU pulls 350-360 W when rendering in Daz if you let it run full bore, so depending on how much power your CPU/RAM/other peripherals pull it my push your total power draw over 600W, which would be cutting it close with a 750 W PSU. However, you can get something like MSI Afterburner for free and use it to run your GPU at lower power (set the power limit to 65-70% and raise the GPU memory clocks 5-10% to compensate) and the effect on rendering time is minimal (in my tests the rendering time for moderate scenes increased by only 5%). In this way you can keep the GPU down to the 250 W range which should be a better fit for your current PSU while still offering the advantage of 24 GB of VRAM to work with.
Also, bear in mind your total system RAM may limit your full use of a 3090. When I had 64 GB of DDR4 RAM on my system I would run out of system RAM on scenes using 18-20 GB of VRAM. Since I have upgraded to 96 GB of DDR5 RAM this problem has gone away and now scenes using 23 GB of VRAM consume 70-75 GB of RAM. Something to think about as well with the new GPU.
I'd give it a go.
As Matt said PSU performance does drop off with age but you have a high quality unit and they're over provisioned to take account off that.
If you turn CPU rendering off, and you should with a fast GPU, then Studio doesn't hit the CPU and GPU hard at the same time.
Total system power draw rendering with a 3090 at the stock 350w power target, without overclocking and CPU rendering turned off is going to use about 330w for the GPU and 100w for everything else. This gives you plenty of headroom for power spikes which is a 30 series and on thing. Gaming would be cutting it close put would probably be ok.
If you have issues then you can undervolt the 3090, or spring for a decent 850/1000. I'd prefer that over settling for the 3060.
Well a 3090 is worlds better for Daz than a 3060. It's a lso a pretty big bump for gaming too. I'd jump on the 3090 then save for a PSU next.
my old build equiped with an RTX3090 on a 850W PSU (i9-10900k, 64G ram, 3 sata SSD, 3 external SSD) for years it was fine, for intense gaming and rendering, but recently everything I render in Daz ended up with my system auto shutdown coupled with a lound fan noise, I suspect it was the PSU running out of juice because I stress tested GPU and CPU independently and both are fine. and it never shut down in gaming. So I'd go for a 1000W PSU if I was you, for the sake of longevity.