If you dreamed of having a PC with one of Nvidia's RTX 3090 graphics cards inside, well how about a machine with four of those GPUs in its case? Puget Systems makes workstations for customers who require extremely powerful setups and has experimented with the idea of a single computer containing four RTX 3090 GPUs, wondering if this might be a viable proposition. And the short answer is that it is, with a few caveats on the diet front. The platform that Puget has implemented (spotted by Videocardz) comes with four RTX 3090 graphics cards as mentioned, along with a 2255-core Intel Xeon W-10 processor backed with 128GB of RAM (full specs here). Powering it all up was an EVGA SuperNova 1600W P2 power supply. Of course, this is a workstation PC, designed for heavy applications; it's far from a gaming machine, and the PC maker has tested it with benchmarks including OctaneBench, V-Ray Next, RedShift, and DaVinci Resolve. These professional applications allow the user to take advantage of multiple GPUs without driver support (or connect them via NVLink, which only supports two 3090 GPUs anyway). The result was that the system performed admirably in these tests, with the power of these GPUs scaling roughly proportionally as more RTX 3090s were added to the mix (up to four). The exception came with DaVinci Resolve, which evolved to three GPUs, albeit with more modest improvements, but the addition of a fourth RTX 3090 did little to improve performance (although part of this could be CPU bottleneck related: this 10-core Xeon was chosen to reduce power demands on the CPU front end). RedShift didn't fare as well when moving three or four graphics cards, either, but still saw a decent improvement.
Advantages of the fan
Puget's RTX 3090 cards were models with Gigabyte's 80mm fans, and the company noted, “This type of fan-style cooling system is much better for multi-GPU setups because it removes most of the heat directly. at the rear of the chassis. . And when it comes to four 350-watt video cards, that's 1.400 watts of heat that we definitely want to get out of the system as quickly as possible. "You're not kidding. In any case, it turns out that from a thermal point of view, this setup worked fine, with GPUs running between 73°C on the bottom card and 80°C on the top card (with the 3090 reaching 88% of its maximum fan speed, which, as you can imagine, made for a noisy PC, but that's to be expected.) So the issue with this experimental RTX 3090 PC quad wasn't with the temperatures or noise, but consumption. power was a bigger issue. The 1600W power supply was able to cope, but it came very close. As Puget points out, it measured a peak power of 1717W from the outlet, which should translate to around 1580 W (the power supply is 92% efficient on the PC, which means "there was 20 W to spare. It's too close for comfort for constant daily operation, of course, so Puget recommends that the The best approach is to use a 2400W power supply, noting, “Most home and office outlets will be on 15-amp circuits in the US, which may mean hiring an electrician to do that. do the electrical work if you choose to use one of the few 2400W power supplies available. Still, if you can afford this kind of PC workstation and have pockets deep enough for four RTX 3090s, the extra electrical work probably won't be much of a problem. Today's best graphics card deals PowerColor Radeon RX 5600 XT ... ASRock AMD Radeon RX5600XT ... ASRock AMD Radeon RX5600XT ... MSI RX 5600 XT GAMING X -...
Via Wccftech