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Comment by jerrygenser | Hacker News Reader

Another thing I've had great success with on my AMD 7700X is to use AMD Ryzen Master to reduce the TDP.

The chip comes to consumers overclocked by default with a TDP of 105W. I suspect this is the case so that it can beat Intel on benchmarks on "default" settings.

You can set it to "eco mode" and have it run at 65W or 45W TDP. Under load, this only results in like a 5% reduction in performance for a dramatic reduction in electricity consumption, fan speed, heat, etc.

Not sure if the 5500x series chips are overclocked but using eco mode could be a good approach.

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Just an FYI AMD Ryzen Master installer contains a dark pattern.

When you first launch it you have to scroll down the disclaimer/license to check off the "I agree to terms and conditions" box (which is obviously unchecked by default).

When you do, it creates the "install button" you can click but the checked box now sits beside text about sending AMD information and if you aren't looking you may assume its still the same text as when you checked the box.

The end effect is to get the user to agree to send data without them noticing.

Just tried installing it, that doesn’t happen (any more). How recent was it that the dark pattern existed?

After you agree to the disclaimer the checkbox disappears and there is no changed text that appears.

I went through the install process 5 minutes before I posted. Using the same installer I recorded a video and converted it to GIF. I redownloaded the installer to check and it still does this.

Note that while its large in the gif because I only clipped the installer, the installer is the entire focus here and the actual window size is small and it was very easy to miss on a full desktop. The installer doesn't full screen and just sits in a little box. You can see text in the background is the regular size text from the hackernews post you replied to in the background to give an idea of relative sizes.

Recording here:

https://i.ibb.co/h2MRz60/AMD-Ryzen-Master-Dark-Patterns.gif

Here's my recording:

https://ibb.co/LnbH6Wy

No idea why I’m not seeing the same thing you are.

totally different. I wonder if its some kind of a/b testing.

Very strange to be sure. Perhaps it’s because my CPU is Intel and not AMD.

No idea. The computer I'm running it on using a 7900X and an RTX 4080.

I’ve tried Eco mode on AMD parts before. The performance drop was a lot more than 5% for heavily multithreaded workloads (compiling), but I could see it being negligible for certain single threaded workloads.

I have AMD and Gentoo. For daily use an eco mode is OK. But at the weekend when I need to emerge, have to use all the power.

But also, now, the deps for $WORK are in pre-buolt docker so I'm not rebuilding nodejs every other weekend.

Interesting we have different reports. My experience was far more in line with parent's in that enabling ECO mode had <5% multicore performance drop (single core unchanged). ECO mode also lowered temps several degrees. Seemed like a no brainer for my use case.

In fact, chips have gotten so fast these days, I am seriously considering running my desktop on a laptop-class CPU. Should be able to run it near silently on air cooling alone with low power consumption.

I've been doing that with a Minisforum bd790i -- a Ryzen 7945HX which is a monster of a CPU (16 zen4 cores, with very high single threaded and multi threaded benchmarks[1]) with a paltry TDP. Minisforum even coined the term "Mobile on Desktop (MoDT)". It's a great platform that is utterly cheap for what you get (mobo w/ PCIe gen5 + CPU + heatsink for less than the price of an individual comparable CPU). Note: This CPU is usually in a laptop with a relatively underpowered cooling solution compared to the linked motherboard with a proper heatsink+fan. Hence the benchmarks have a very wide spread due to varying (usually laptop-based) cooling.

Pertinent to the conversation though, the BIOS is very much lacking, and supposedly software-based fan control is not implemented. That said, running the fans constantly at ~silent levels of rotation keeps the temps cool (you can even run the heatsink without a fan if you want).

[0] https://store.minisforum.com/products/minisforum-bd770i?vari... [1] https://www.cpu-monkey.com/en/cpu-amd_ryzen_9_7945hx

AMD 7700X is probably factory overclocked 7700, it would be cheaper to just buy 7700. Probably the only difference is that some of the 7700 chips cannot guaranty same clocks and stability when overclocked to 7700X specs.

The current price difference on Amazon is $5. But the 7700X doesn't include a cooler. If you're not planning to use the AMD cooler, may as well pay an extra $5 and get a processor that binned better (probably), not have the extra cooler, and you can fiddle with voltage and TDP/power limits from there.

Depending on your cooling, having a 100Mhz higher max clock could be worth $5.

I know someone that bought an AMD CPU but it was a factory-sealed empty box. Turned out sending out a cooler-free product in the same packaging allowed for the CPU to be taken out of the box's window without breaking the seal. Hopefully they've updated the packaging.

I don't know about the 7700, but I have a 7900 and it makes the 7900X look utterly ridiculous in comparison, especially because it comes with a decent cooler (incl. RGB if people care for that). So yeah, I'd not waste extra money on the X variant. (Though for games, the 7800X3D is probably the best of the bunch)

Same with GPUs - reducing the power budget on a 3080Ti down to like 75% reduced the performance by maybe 5-10% but dramatically reduces noise and heat produced.

What do you use to undervolt your GPU?

MSI Afterburner works great, no matter what is your GPU brand.

On Linux you can use nvidia-smi to set a power target directly in Watts, works well.

That doesn't undervolt. On Linux you 'cannot' undervolt as the userland software doesn't support it, but there's a trick.

Instead you can overclock, which moves the curve to the right (same voltage for a higher frequency), and then add a clock speed limit. You are now running the same frequency at a lower voltage.

The main problem with the AMD 5000 series is their high idle (non-core) power draw of around 20 to 30W.

AMD have reduced this in their 7000 series.

Got any specific numbers?

On the Intel side of things, I've seen my 14700K idle at around 5W (which shoots up to 300W under load, I find it greatly amusing) and my 12700H at 0.5W or less.

My 5900x, with core parking on and energy saving windows settings idles at 45W package power. Only two cores are really active, one each at ~2/3W. The others at <0.1W.

My 5950x idles at 35W. It's a known problem with AMD. It isn't the CPUs using the power its the uncore/SoC that eats the power.

You can also undervolt most modern AMD parts and actually gain performance

How does that work? Is it just that it can run at high speed sustained if it doesn't have to dissipate as much heat?

The chips overclock themselves under load but it's unsustainable. Limiting their TDP can allow them to sustain their overclocks longer/indefinitely.

Yes, exactly. Modern chips thermal throttle by default, their turbo clocks/voltages aren't sustainable with most cooling solutions, so, reducing the voltage the chip runs at lowers the power consumed and allows the chip to maintain a higher clock for longer durations.

There is, of course, a risk that the lower voltage won't be stable, but, as long as you stress test your system as you would while overclocking, you'll be able to find a lower voltage that is workable.

The 7000 series ryzen chips have this built into most motherboard bioses by the name 'pbo offset' (or similar) which modifies the stock voltage curve lower, and can set new temperature targets if desired. I'm running my 7950x at PBO level 3 with an 85c target, works well with no more fuss than a couple reboots really.

> their turbo clocks/voltages aren't sustainable with most cooling solutions

And also, starting with 7nm it becomes a lot harder to transfer that heat out of the chip, even if you have thermal mass. The IHS itself becomes a bottleneck.

On X3D chips it gets even worse, as the cache acts as a heat shield too - these chips actually are pre-binned running at relatively low voltages, which is why they usually don't see as huge gains in as others in curve optimizer.

I had a similar problem to what the article describes with a Ryzen 9. The reason was the the CPU would constantly automatically spike the clock frequency to overclock the CPU. The solution was just to disable this specific feature in the BIOS.

Yes, you can do the same with the 5000 series. The 5600X can be restricted to 45W max tdp & the 5800X to 65W.

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