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Comment by jeffbee | Hacker News Reader

Yeah, these Zen 5 are killer for that kind of workload. I also replaced my workstation with a 9900-series CPU since my Intel 14900K fried itself, and I am very pleased with every aspect, except idle power consumption which is a minor drawback.

It looks like the X3D is no better than the 9900X for non-game single-threaded workloads like browsers, and it's much worse than the 12 or 16 core parts in terms of overall throughput, so for a non-gamer the plain X seems much better than the X3D.

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What's your idle power consumption for AMD vs Intel if you don't mind me asking? I'm getting avg 125W for my 13900k build, measured at the wall and it mildly bugs me when I think of it, I thought it'd be closer to 80. And power is very expensive where I live now.

7950X3D, 96G, 18TBx4, 4TB NVMe x2 my GPUs are gtx1080, rx570 and the 7950x3d, FSP 1000W ATX3 platinum

I use proxmox as my OS. I have a truenas VM with passed through storage. I have a few VMs and a couple of gaming VMs (Bazzite, Fedora, NixOS)

After boot idle is around 180-200W because the GPUs don't sleep. After VMs runnning with GPUs this goes down to 110W. My drives don't spin down so thats around 20W.

If you are getting 125W at the wall on a PC at idle, your machine or operating system is extremely broken, or you are running atmosphere physics simulations all the time. The SoC on my Intel box typically drew < 1W as measured by RAPL. The 9950X draws about 18W measured the same way. Because of platform overhead the difference in terms of ratio is not that large but the Ryzen system is drawing about 40W at the wall when it's just sitting there.

Discrete gpu can easily add 20-40w of idle power draw, so that's something to keep in mind. I believe that 60ish watts is pretty typical idle consumption for desktop system, Ryzens typically having 10w higher idle draw than Intel. Some random reviews with whole system idle measurements:

https://hothardware.com/reviews/amd-ryzen-7-9800x3d-processo...

https://www.techpowerup.com/review/amd-ryzen-7-9800x3d/23.ht...

Those comparisons are using a water cooling rig which already blows out the idle power budget. 60W is in no way typical of PC idle power. Your basic Intel PC draws no more power than a laptop, low single digits of watts at the load, low tens of watts at the wall. My NUC12, which is no slouch, draws <5W at the wall when the display is off and when using Wi-Fi instead of Ethernet.

Hmm. I’m using an AIO cooler, a 3090 and a 1600W platinum psu - might be a bit inefficient. I remember unplugging the PSU and 3090 and plugging in a 650W gold PSU — the system drew 70W IIRC. That’s a wild difference still!

Yeah, oversized power supplies are also responsible for high idle power. "Gold" etc ratings are for their efficiency at 50%-100% rated power, not how well they scale down to zero, unfortunately. I have never owned a real GPU, I use the IGP or a fanless Quadro, so I don't have firsthand experience with how that impacts idle power.

Gold rating is down to 20%, Titanium is to 10% https://en.wikipedia.org/wiki/80_Plus#Efficiency_level_certi...

Platinum is 90% efficient at 20%, but OP is using a 1600W power supply, so that 20% is 320W. Any load below that is going to be less efficient.

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