Standy power consumption of hi end PC - Page 1
Forum section: electronics / general

author: Circlotron
author_rank: Super Contributor
timestamp: October 24, 2023, 02:30:58 am
content: Just toying with the idea of getting a way better PC, something with a decent graphics card that can run AI stuff, and a CPU with a bit of muscle. Probably something similar to a gaming PC but without all the ridiculous light show. When such a unit is being used for games the heat dissipation and consequently the power consumption gets way high, but what about when it is just ticking over while you are reading eevblog stuff? Or staring at code wondering why it doesn't run. What is the power consumption like then? Is is similar to a low level pc or is it still notably high?

author: Elghinnarisa
author_rank: Newbie
timestamp: October 25, 2023, 02:00:31 am
content: Depends quite a bit on, well a quite a bit.The idle efficiency of hardware varies quite a lot these days, even more so when "hi end" is not particularly specific. And is also highly influenced on how well it can enter the lower states. Which can easily be ruined by improper UEFI configurations, wrong power plan, or a pesky process in the background being naughty. Or any external devices you have connected to it over USB etc.I grabbed a few measurements from my setup, which would have been reasonably high end from last generation. I listed the details of the computer in question below.MSI B550 tomahawkRyzen 9 5900xCorsair 32GB 3600Mhz with EXPO on (this can make a difference)RTX 30702x 8TB WD RED4x assorted 2.5" SSD2x NVMe SSD5x 120mm case fans (no RGB)Noctua NH-D15 cooler (2 fans)USB devices:Backlit keyboardWireless mouseWebcam1x 4 port powered USB hub2x Oculus rift sensorsOculus CV1 headset3 monitors connected to said system, 1440p x2 and 4k, which relates to whatever the GPU consumes.I did 3 quick measurements. Motherboard + GPU RGB on, then one with them off, and then one scrolling a few websites and poking around VS code. I measured everything from the wall with a power meter so fancy it doesn't even have a model name on it. A proper 30 bucks in a random store a few years ago. It had a 15min settle time before starting any of the collection. Recorded the measurements and averaged a 3 min period. Which is not long, but I had been at it almost a hour and I was getting lazy since I had to write it down manually. It was mostly to see what the consumption is roughly at, and how much of a difference it makes.LED off : 118wLED on: 122wweb browsing/code: 129wWhich is kinda what I expected. It's a pretty packed system and every little bit adds up. A couple of watts for the USB stuff, a few more for the storage devices, throw in a couple more here and there for the fans.It makes a significant difference on the Zen series of CPUs how you set it up as well. Out of the box mine was a proper power hog. Now it's mostly tweaked for high end performance, not low idle consumption. The 5900x is generally sitting somewhere around 45-50w during idle. Which is quite high, but also not unexpected for a processor of this type. It is not made to sit around doing nothing and mine tend to average ~75% load over the course of months, I bought it to use it.One could definitely get this down a bit, i'd say 70w would not be unreasonable to reach. Less monitors connected, throw it in eco-mode, disable backlight on keyboard etc. Not having as many drives also helps to shave off a bit.A more modern and suitable system could probably go down to 45-50w, a bit lower. But thats pushing it for a high-end system. There is quite a lot of stuff running even when you arn't loading the hardware particularly much. Motherboards are pretty packed these days. I'd argue a Intel system would have lower idles, with their efficiency cores and all that. Drawback there is the insane load usage instead.Well it's not much, but it's something at least.

author: Shonky
author_rank: Frequent Contributor
timestamp: October 25, 2023, 02:22:05 am
content: What's "notably high"? You might be talking about ~100W for a high power machine vs maybe 50W for a lesser machine.My RTX3070 reports 20W right now writing this post running a 4k screen and just displaying lower power applications like you describe. A PC with a high end graphics card is always going to use more power than one without even if the extra hardware is not being exercise.Also the term you are looking for is idle, not standby. Standby is a much lower power mode and should be comparable between systems since it basically shuts down almost everything.

author: SiliconWizard
author_rank: Super Contributor
timestamp: October 26, 2023, 03:53:55 am
content: A "desktop" machine (using a "desktop" ATX motherboard, typical mid-range CPU, reasonable GPU and all of the required peripherals will idle at around at least 100W - which Elghinnarisa gets here as well.My workstation idles at around 130W. It has a 135W TDP CPU and a mid-range AMD GPU, 4 SSDs, and a few USB peripherals.Don't expect much lower than about 80W-100W in "idle" with a desktop-type computer, even with much lower peformance. I mean, what really gets sucked out of the mains plug.If you want something definitely less power hungry, use a laptop, or one of these mini-PCs which also use components targeted at laptops, usually.

author: DiTBho
author_rank: Super Contributor
timestamp: October 26, 2023, 05:59:57 am
content: use an Apple M2 laptop

author: Ranayna
author_rank: Super Contributor
timestamp: October 26, 2023, 12:50:59 pm
content: Also important regarding idle power: Just having a second screen connected can increase power draw of GPUs by 20 or more watts.So, if you are just idly browsing or watching videos, it may actually make sense to turn any unused screens off.

author: David Hess
author_rank: Super Contributor
timestamp: October 26, 2023, 04:57:32 pm
content: I have been rebuilding my old 8GB Phenom II 940 workstation and took some measurements. It has 2 SSDs, 0 hard drives (I disconnected them for this test), built in chipset motherboard graphics, a USB keyboard, a USB Mouse, one HDMI monitor, and an assortment of expansion cards including an Areca PCIe 1230 RAID card, an Intel PCI (!) Gigabit card, an ASMedia PCIe 2 port SATA 3 card, and a 2 port Intel PCIe Gigabit card,.With the system off but powered, it draws 4 watts.At idle after startup and logging into Windows 10, it draws 88 watts which is higher than I expected, but the expansion cards add up.Under full CPU load it draws 160 watts.After various background services have started, it draws about 120 watts. Task manager says that "System interrupts" are taking 7% of the CPU.I could take measurements of my "modern" systems but they all have hard drive RAID arrays which I guess is not what you are interested in.

author: John B
author_rank: Frequent Contributor
timestamp: October 26, 2023, 07:23:01 pm
content: I've recently built a small ITX system, which now idles at around 40W.While testing and building it, I noticed that a 550W ATX PSU consumed more power at idle compared to the Flex ATX 1U PSU it now uses, somewhere around 15W.Also the operating system clearly plays a big part, I ran both Linux (around 60W idle) and Windows (40W idle). The ASUS drivers for Windows probably have driver tweaks to manage the power on the motherboard, putting various controllers into low power or shutdown states. I'm sure there's some way to tweak it in Linux....There's going to be a inherent power jump in using a discrete GPU over integrated graphics.

author: ksio89
author_rank: Contributor
timestamp: November 02, 2023, 11:23:08 pm
content: Quote from: Shonky on October 25, 2023, 02:22:05 amQuote from: Elghinnarisa on October 25, 2023, 02:00:31 amI don't have a power meter, so could you do me a favour and check how much your PC consumes during S3 sleep? I use it a lot and always wondered how much it's pulling from the wall.

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 04, 2023, 01:53:28 am
content: Could one use Optimus/PRIME for power saving on a desktop?

author: MathWizard
author_rank: Super Contributor
timestamp: November 18, 2023, 06:20:25 pm
content: I think some people mix up looking cool, with being cool, when it comes to keeping PC's cool.I hate it when they put lights on my fans. I guess a few LEDs doesn't matter compared to 100's of Watts coming out of a heastsink. But they are putting them on everything, even on small hot things like RAM and those mini PCIe SSD's.

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 18, 2023, 08:22:58 pm
content: Quote from: MathWizard on November 18, 2023, 06:20:25 pmJust get some Delta fans. They're designed to just work well, but you'll have difficulty finding them in any color other than black.