Even with the world's highest electricity prices, my high-end PC isn't the energy hog I expected
Even with the world's highest electricity prices, my high-end PC isn't the energy hog I expected
Summary: Living in Ireland, my electricity prices have gone from bad to worse in recent years, and a recent further price increase across most of the providers has pushed us to either the top spot in terms of energy prices in the world, or second place, depending on who you ask. Plus, some have had us at the top spot for several months at this point. With that price increase has come a re-evaluation of all of the tech that I use, with an attempt to consolidate as much as I can and to decrease the power usage of my appliances, too. As it turns out, though, your PC probably doesn't consume a whole lot of power.
Living in Ireland, my electricity prices have gone from bad to worse in recent years, and a recent further price increase across most of the providers has pushed us to either the top spot in terms of energy prices in the world, or second place, depending on who you ask. Plus, some have had us at the top spot for several months at this point. With that price increase has come a re-evaluation of all of the tech that I use, with an attempt to consolidate as much as I can and to decrease the power usage of my appliances, too. As it turns out, though, your PC probably doesn't consume a whole lot of power.
For reference, my PC's specifications are fairly overkill, so I fully expected even the idle power draw to be high. Yet, despite my assumptions, the power draw is surprisingly efficient, and as I tested more, I was surprised to see that there weren't a lot of differences between different hardware configurations.
First and foremost, I'll go over my PC's biggest drawers of power. Those are the AMD Ryzen 7 9800X3D and the Nvidia RTX 5090 , both powerhouses in their own right and capable of a significant amount of computation and, therefore, power consumption. With my peak rate going above €0.50 per kWh (that's around $0.60 per kWh), I started to look into undervolting techniques and trying to conserve power. However, my primary Proxmox node with all of my self-hosted services has an Intel Core i7-14700K with an AMD Radeon RX 7900 XTX, and it idles at 80W. So, I decided to investigate further.
Before making any tweaks, with a lot of applications and browser tabs open, I was looking at approximately 200W to 250W of power being drawn. Given that I work from home, some power draw is inevitable, and I don't necessarily have a problem with that on the outset. It sounds high, but how high is it, really? What alarmed me more was the fact that, while gaming, this would be even higher, and games like Counter-Strike 2 saw my energy consumption spike anywhere between 500W and 700W at any given time during a play session.
Yet, when I stopped to think about it and do some math, it actually isn't as bad as it sounds, Drawing 250W consistently for an eight hour work day would only cost me a single euro in electricity, and that's if I was paying my peak energy pricing for an entire day, rather than the short few-hour window that it's active. This surprised me, as I often see people trying to get their energy consumption down and talking about their computers being a massive hog of energy. If I were to put in an eight-hour stint of Counter-Strike drawing a full 700W of power that entire time, it'd still only cost me €2.80, and that's with the incredibly high rates of electricity that we have.
And to make things even more interesting, I calculated the costs of running my home server, with that peak electricial tariff of €0.5. Even then, a full 24 hours of usage at its peak power consumption (as it routinely spikes to 100W of energy consumed, not including local AI workloads), only costs €1.20 a day if I were to calculate it with my peak electricity cost for 24 hours. That's a little expensive as it adds more than €60 to my energy bill every two months, but I also undoubtedly save €60 in those two months on the subscriptions I no longer pay for (Overleaf, Obsidian Sync, and more). Keeping in mind that I still pay a cheaper night-time rate, and coupling it with the fact that it's not uncommon to pay money towards a hobby, that's really not too bad.
So, if you're concerned about your energy usage, chances are, you shouldn't be. I'm not accounting for monitors here (which obviously do contribute quite a bit of energy usage, too), but the long story short is that your PC is surprisingly efficient. A dishwasher can use anywhere from 1.2 kWh to 2 kWh, and a washing machine can be up to 1 kWh of energy usage. To get five hours of computer usage on average for the same energy usage as a single washing machine cycle isn't all that bad, really.
If you're still curious about saving on your energy consumption, though, then I have some tips that can help massively.
So you've decided you want to cut down your PC's energy usage; what steps can you take? The most obvious and most impactful that I've found has been to undervolt both my CPU and my GPU. When you get a new CPU or GPU and set it up, all of the voltages are preconfigured in a way that's standardized to maximize stability across every instance of that hardware. Not all silicon is created equal, and this is why you hear about the "silicon lottery" when it comes to overclocking. It goes the other way, though, and some chips will run better at lower voltages than others.
As a result, it's a bit of a guessing game, but for the most part, pretty much every chip can be undervolted to some degree. Not only does this result in less power consumption in both your CPU and your GPU, but it reduces thermals and can even result in more consistent performance thanks to the lack of thermal throttling and further clock speed boost opportunities. Right now, I have a curve optimizer of -15 on my 9800X3D for undervolting, and the highest voltage my RTX 5090 runs at is 0.95 V while clocked at 2.8GHz.
Undervolting methods will differ entirely on a per-CPU and per-GPU basis, so be sure to do research on your particular card to figure out the best way to do it for you.
With just those two changes, my idle wattage dropped from between 200W and 250W to between 170W and 200W. The CPU can definitely be undervolted further (-15 is considered a "safe" value) and I'm sure I can tweak the GPU some more. I've ran a number of stability tests for both, and both operate completely normally. As for gaming, that peak 700W that I mentioned has now dropped to between 400W and 600W, which is a big difference. To go back to that eight hour gaming session, a drop of 200W (if we were to go from 700W peak to 500W) will yield savings of almost a euro over that play session.
Finally, here's an example where it doesn't really matter, but can also yield savings if you're trying to save every penny that you can. My entire system is RGB, packing a Corsair H100i Elite Capellix, and the fans in my case are RGB, too. At complete idle, my PC was drawing roughly 172W, and disabling all of my RGB inside of my PC dropped it to 160W. However, assuming a 12W saving for 24 hours straight in a day, that only saves €0.14 every single day... or just over €8 every two months.
When looking to decrease your energy consumption, there are many steps you can take that yield a lot of results, but some, like these, aren't worth it. You bought your RGB, so use it, unless that €8 every two months is something you really need.
Part of the reason these numbers are surprisingly tame is because PC hardware has steadily become more efficient over the years. CPUs and GPUs still advertise enormous peak power consumption figures, but every major hardware vendor has introduced increasingly sophisticated power management systems that dynamically adjust usage based on workload. That means that your hardware isn't constantly running at its advertised maximums, but instead shifting power up and down in response to what you're doing. Case in point: my Proxmox system with a 14700K and a 7900 XTX actually idles at a power draw slightly below the previous sytem I used, which had a Ryzen 7 3700X and a GTX 1070 Ti.
What's also worth mentioning is that many supporting components in a PC have quietly improved. Modern DDR5 memory, for instance, can run at higher frequencies with lower voltage, ands olid-state drives also use much less power than mechanical hard drives ever have. Even modern motherboards are nowadays equipped with efficient VRMs and standby systems, and every one of these improvements add up to result in a more powerful yet still more efficient computer than those which were on the market a couple of years ago.
Funnily enough, my networking hardware isn't actually too far off my PC's power consumption on a day-to-day basis when factoring in the 24-hours, seven-days-a-week nature of it. My OPNsense machine (with four HDDs), four-port managed switch, and a single mesh Wi-Fi node all draw approximately 1.58 kWh of energy every single day, whereas my PC can draw anywhere from 3 kWh to 4 kWh a day. It's a pretty stark reminder that a few hours of gaming here and there isn't what leaves the most damage in your energy bill; it's the day-to-day appliances you need or the always-on electrical devices that you keep running every single day.
All of this isn't to say that it's not a pointless endeavor to try and optimize. Not only can every cent count when it comes to energy consumption, but you can end up with real performance benefits with the right undervolt, too. Chasing lower wattages isn't always worth it, and the miniscule cost savings as a result of disabling entire features like RGB or removing additional hard drives simply isn't worth it for most people.
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