I am calculating I need around 1700-1800w for a power supply… I’ve got a 1550w (had only a 3090 and a 1080Ti before). I’m running out of a home office and would like to avoid running another circuit if I can (so not looking to run a new 240v). I am trying to research dual PSU solutions, but I am not finding a way to make that work in the Define 7 XL. Any thoughts/suggestions would be much appreciated.
If you calculated you needed a 1500w and you then find out you are only using 1100w (As an example) under load, then you know you have more headroom than you think. You can also determine if you really do need to run that extra circuit.
Personally I suspect a 1550w would be fine, but I don’t have much experience with that much GPU.
Another idea is to do something like this:
Then you could easily run a cord to an outlet on another circuit, and have the load split between 2 circuits by having 1 PSU in either
Yet another idea, where does that circuit go? Is it just outlets, and maybe just one room? If you really want to get spicy, grab a double pole breaker of the correct size for the wire and reallocate the neutral as another hot to make the circuit 240v, and of course change out all of the receptacles to be NEMA 6-15R. Now you have double the power!
Current system is this machine. I’m upgrading from
a 3090 and a 1080ti to three 3090s and from 256GB to 512GB of RAM. I built this system in the middle of the shortages and had to go with what I could get.
I think the suggestion of getting a meter and checking the actual draw is a good idea. In my work so far I’ve had the 3090 go to around 320w under load (as reported by nvtop) but that is anecdotal based on my watching it while running trainings.
I’ve also realized is that with my workloads I’m rarely loading the CPU and GPUs at the same time. When running training on the GPUs, there isn’t all that much for the CPU to do, and when I’m prepping data and such there isn’t much for the GPUs. So it probably isn’t likely that I’ll draw max load across the whole system at once. Still, words like “probably” and “likely” make me nervous.
Anyone with experience with this much GPU have any tips? I ended up going with the 3090s because of availability/price, now I’m wishing I’d pushed for the A6000s or A5500s.
Small curiosity measure be through Phanteks
Phanteks came up with a Dual System PSU, along with a Redundant-friendly PSU
Better to play it safer, with higher wattage, since the bigly spike potential of 3090s
… Let alone, talking about handling 3x of them
Isn’t much a price difference, between the 850W and 1000W variants [$30 RRP Diff]
Don’t recall Define series, supporting dual PSUs… Backpedal to the drawing board
Look at likes of Phanteks Enthoo Pro 2, Lian-Li 011 Dynamic, Enthoo 719, etc.
You are correct that the Define doesn’t have Dual PSU support. Looking at the cases listed, it looks like I wouldn’t have space for both my 420mm radiators. With the Enthoo Pro 2, it looks like I could put the 420mm in the front, and swap out for a 360mm up top. I see it can fit another 360mm on the bottom, but I don’t think that would work if there is a second PSU. I’m wondering if a 240mm would fit in the bottom with a second PSU. It looks like there would be room for that (can’t really tell how far back the fan mount is from the front of the case in the manual).
So maybe a Enthoo Pro 2 w/ Dual PSU and 360mm+420mm+240mm? I -think- I would still have room for my 2x3.5" drives and the pump/res combo, but I’m having trouble finding examples of such a build. I’m also a bit concerned by the top clearance on the case if a 360+fans might be a bit tall and would crowd the motherboard. Maybe slim rads top and bottom?
My plan right now is to complete the build with the parts I have, and do some testing to see how stable it is under load. If I see issues, I’ll plan to swap cases/rads as a plan B.
Those 3.5in drives are gonna create far more restrictions, to planned radiator runs
IF you’re able to swap with 2.5in drives, it can open up with larger combinations
…+ That would be looking past, the Enthoo Pro 2s layout
The problem is the need for the capacity to have datasets available locally. I’ve already gone as far as I can with NVMe to make sure I can have a good working set available, but I need the extra space (~30TB as of right now, honestly I’d love to have more) for archive/training sets. I would have to get a lot of 2.5" drives for that much space.
I could look at building/buying a NAS or something for even more storage, but that is a large/expensive effort in itself. I also don’t have a 10Gb switch at the moment, and a 10Gb NAS seems it would be expensive as well.
Maybe I can look at moving to some kind of external sas enclosure, I have one free pci-e slot that isn’t covered by the GPUs maybe I can stick an LSI card in there for a 4-bay external enclosure or something. Probably cheaper than a NAS with better performance.
Well… 30 TB of data is a lot, but a 3.5" HDD drive can only transfer at roughly 1.6 Gbps maximum. Honestly you might be better off putting that archive on a server storage somewhere instead. Even at 1 GbE you will reach roughly half the capacity of the theoretical maximum of HDDs, 2.5 GbE will definitely saturate single SATA and 5 GbE will saturate RAID0 dual striping. No need for a switch if both are in the same rack (e.g. close physically), just run a network cable directly between the NAS and the trainer e.g.
That way the NAS can be any PC with a bunch of drives in it.
Anyway, I second that you should monitor the wattages from the 3090s. Not sure if you win anything on the water cooling, and might want to look into a high end PSU with internal watt monitoring. As far as I can tell though, 3090s can reach upwards of 550W, so you might want to tone down to a 3080 Ti perhaps. I do not think finishing 5% faster merits the higher cost for the 3090, but I could be wrong.
I am RAID0 stripping them right now. I’ve got backup in the cloud for the datasets, I will probably look into setting up a “real” storage server in the future. In the short term, I’m actually really liking the external array idea using a Mini-SAS connection. I could double to 4 HDDs, RAID 0 and hopefully get decent performance.
On the 3090s, the great thing about the 3090 for me is more the 24GB of RAM, some of the models I have don’t fit in 12GB. I’ve been pretty limited on what I can get my hands on until recently. And honestly, water cooling is more about reducing the size of the cards so they don’t cover 3 slots so I can fit more in the machine. Also, it is quieter.
This looks like something cool: IPC PSU FSP-FC250 | FSP TECHNOLOGY INC.
Though not exactly sure what kind of cables you would need on the backplane.
And it would be probably very loud because it’s normally used in servers.
