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Comment by mastax | Hacker News Reader

> And it is basically impossible to hit the 230W power limit at stock without direct die or sub-ambient.

Almost, but not quite. In GamersNexus' review they recorded 250.8W measured at the EPS12V cables, while using an Arctic Cooling Liquid Freezer II 360mm AIO with the fans at 100%. At 230W/1.5V=153A a good VRM will generate about 17W of heat. That leaves you a few watts for board power plane and socket resistive losses (I don't have an estimate for that).

Not a very practical cooling solution for a day-to-day workstation, but I do wonder if you could reduce the fan speeds a bit while still maxing out the power limit.

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Worth noting that GN measured the power before the VRMs, while the limit is applied after the VRMs. Assuming a 90% efficiency, what GN measured would be 225.7W at the socket. Close, but still not quite.

I accounted for VRM efficiency losses in the second sentence, using data from a real X570 VRM.

What if you assume 91.7% efficiency?

Then again, I have 2 420mm Black Ice Nemesis radiators in my custom loop - even at relatively low speeds it can keep the 5800X in there and 3080 Ti cool under constant high loads.

My mini-ITX work desktop has no problems with a 5900x and a Radeon VII pro running Rocm work, using only a tiny heatsink on the 5900x (and some high-airflow fans, but nothing too incredibly loud). It doesn't thermal throttle, but tops out around 80-90 degrees C.

The 7000-series seems to be a different story: you really need a big cooler for those chips.

I have the same CPU + GPU combination, but used on an ATX MB with a Noctua cooler with a double 120-mm fan.

While the larger case and cooler makes the cooling easier, the fans are normally inaudible and the CPU stays under 45 Celsius degrees when not doing heavy work, and the temperature may raise up to a little over 60 degrees Celsius when 100% busy.

From what I have seen until now, cooling will no longer be so easy for the 7000 series, unless you choose to run them in the Eco mode.

What computer case/chasis are you using that fits those radiators? Was it an easy build?

Corsair 7000D Airflow - it's a full tower.

Easy build, the case has a lot of room to route. I went with ZMT tubing rather than hard tubing, as I didn't want to deal with rigid fittings, I prefer the aesthetic, and it's easier for routing when you can have things other than right angles!

One important note - the front rad is an X-Flow rather than traditional U-Flow.

Amusingly, there seems to still be 70% of performance if limiting the power to 65W.

This means the default power limits are not reasonable, and only there to win the release day benchmarks.

It seems that the return of competition has led to increasing power draw. At least in the enthusiast market where, it seems, customers don't care much.

I care more about my time than I do about my power usage.

I feel like AMD having their "eco mode" is a pretty good solution - it allows the user a pretty easy method of deciding if peak performance or efficiency matters more to them. Better than a separate SKU for each.

Though this comes at the expense of reviews possibly judging things based on the "incorrect" setting

You can already do something like this if you aren't afraid to go deep into bios settings.

Not every computer is going to have have great cooling. Small cases won't be able to cool the full power and will end up heating up and throttling, which will produce hiccups in the GUI.

Yes, PPT is the setting, expressed in watt.

This definitely works on Zen2 onward, unsure about Zen/Zen+.

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