We’re revisiting an old topic. A few years ago, we posted an article entitled “How Many Watts Does a Gaming PC Really Need,” which focused on testing multiple configurations for power consumption. We started working on this revisit last week, using a soon-to-be-released Bronze 450W PSU as a baseline, seeing as we’ve recently advocated for more 400-450W PSUs in PC builds. We'll be able to share more about this PSU (and its creator and name) soon. This content piece shows how far we can get on lower wattage PSUs with modern hardware.

Although we’ll be showing an overclocked 7700K + GTX 1080 FTW as the high-end configuration, we’d recommend going higher than 450W for that particular setup. It is possible to run on 450W, but we begin pushing the continuous load on the PSU to a point of driving up noise levels (from the PSU fan) and abusing the power supply. There’s also insufficient headroom for 100% GPU / 100% CPU workloads, but that should be uncommon for most of our audience. Most the forum builds we see host PSUs ranging from 700-800W+, which is often overkill for most modern gaming PCs. You’d want the higher capacity for something like Threadripper, for instance, or X299, but those are HEDT platforms. For gaming platforms, power requirements largely stop around 600W, sans serious overclocking, and most systems can get by lower than that.

There are two ends to a power supply cable: The device-side and the PSU-side. The device-side of all PC cables is standardized. ATX 24-pin, EPS12V, PCI-e to the GPU, SATA—the wiring is known, and it doesn't change. What isn't standardized, however, is the layout of the PSU-side modular cable headers. Some vendors might use 6-pin connectors for their PSU-side peripheral headers (identical to what's found on PCI-e cables, because it saves cost), others will opt instead for a wide-format pin-out for the same. Another still could use a bulky 9-pin block for universal connectivity, like some of EVGA's power supplies.

What can't be done, though, is mixing cables between all these units. Or at least, it shouldn't be done. Mixing cables between power supplies can kill them or kill attached components. Not always, but it can -- and when the wiring crosses in exactly the wrong way, the failure will be spectacular. Like ESD, just because you've gotten away with mixing cables doesn't mean you always will. Electricity is not a mystery; we know well how it works, and crossing the wrong wires will damage components.

This week's Ask GN episode answers viewer questions about FinFET vs. Planar, the impact of cooling on power consumption, CPU load for 120Hz / 144Hz displays, liquid cooler testing, and a few extras. We spend most the time talking liquid coolers and cooler testing – a fitting topic, having done multiple “Hybrid” video card builds lately.

The full list of questions with their timestamps can be found below the video. Thanks to our viewers for the questions and, as always, post more in the video comments on YouTube for inclusion in next week's episode.

A bad power supply can cause a number of issues – in fact, it can even “pop!” and die. Other issues include bad regulation, response to load changes, and poor efficiency. Another consequence is volatile voltage ripple.

We will first cover what voltage ripple is, then how it affects users, and we’ll end by quantifying voltage ripple objectively.

The silicon powering modern microprocessors consumes significantly less wattage than consumer technology leading up to this point. Look back at the GTX 400 series (Fermi) for an example of this: The flagship GTX 480 was 250W, and it ran damn hot, too. NVidia acknowledged this when we toured their facilities, noting that the complaints of noise, heat, and power consumption directly impacted the development of Kepler units. To put things into perspective, the GTX Titan also draws 250W and has approximately 2.5x the transistors over the GTX 480 (7.5B vs. 3B).

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Despite the overall trend toward improved power-to-performance ratios, a mid-range gaming machine can still easily pull 500W+ under full computational (CPU/GPU) load -- that's a lot of power. Even idle, without BIOS advanced power saving features configured, you could easily be resting on a couple hundred watts. Personally, I've got almost a constant system up-time, and that consumes a lot of power. In order to mitigate power consumption and the electric bill (~$20 / mo. with full up-time on my machine, dropped to $10 / mo after taking these steps), we can use modern advanced power saving states implemented by Intel and AMD.

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