Hacker News new | ask | show | jobs
by SketchySeaBeast 1385 days ago
Between this and the ridiculous TDP expectations for this generations latest graphic cards people are going to have to start thinking about using dedicated circuits per gaming computer.
13 comments

It certainly makes building Mini ITX a lot more interesting when you're trying to get the sweet spot for performance to thermals/noise ratio.

I did a nCase M1 build recently and my objective for the build was small as possible, quiet as possible, and as powerful as possible in that order. I still ended up with a pretty powerful machine by going with an i3-12100 instead of an i5/i7 which uses much less power and puts out less heat. The RTX 3080 reference card was the biggest card that could fit into the case which I undervolted.

A lot of people are undervolting their RTX GPU's because for an only about a ~3% performance loss you get about 10C less temp which translates to far less fan noise. I don't know why Nvidia doesn't just have a one click button for people.

nCase unfortunately have discontinued this case based on 'market factors' which I suspect means that they don't anticipate things to be getting smaller and cooler any time soon.

>A lot of people are undervolting their RTX GPU's because for an only about a ~3% performance loss you get about 10C less temp which translates to far less fan noise

Bah, this is brilliant. I just upgraded a 1070 to a 3070 and am flabbergasted at how much heat it dumps into my room. One of the reasons I did not go with the 3080 was the ~100 watt lower draw.

Do you know of any good tooling to assess the impact of undervolting or is it a manual guess-and-check process?

Trial and error. You need to dial in the right point on the voltage/clock frequency curve for your workloads, AKA "just play some games and look at the results." Just use whatever your overclocking software for your motherboard is, and modify the default curve it has. I use MSI Afterburner and just set a flat clock frequency (plateau) at a certain voltage level to undervolt. I think for NVidia GPUs there's a way to modify the curve with the default tooling, but third party tools like Afterburner can also do it.

You can get great results pretty fast this way. My Mini-ITX build is about as thermally compact as possible given the parts (3080+Ryzen 5600X, NZXT H1), and I'm pushing my PSU to the absolute limits in the stock settings, so undervolting is important for safe power margins since the 3080 can reach ~360W in my testing. I think 30 minutes of tweaking got me something like a +80W power drop for only 10% FPS in Read Dead Redemption 2 @ 4k60fps; I never breach 300W now which is within my personal safety margins, and can native 4k everything.

Some software like Afterburner have "Overclock Scanner" tools that will run benchmarks and repeatedly try to dial these settings in for you, but it really is easier to just modify the curve manually and test your specific workloads.

I just built a Ryzen 5600G system (without a discrete video card atm) and you can set either temperature or power consumption limits in the BIOS and it will underclock itself (actually turbo boost less) until it obeys your limits.

Perhaps I'll wait with the video card until they give me the option to do the same there...

Make sure to also cap your FPS or use Vsync. No point pumping out 100fps when you have only a 60hz TV, etc.
This is the correct answer to tackle power draw. Use Vsync/Adaptive Sync for fixed refresh monitors, or FreeSync/GSync for variable refresh monitors.

For variable refresh rate monitors, it's best to use framerate limiters as well: either in-game or in the Nvidia control panel. Set the cap at least a few fps lower than your monitor's max refresh rate. Even better, aim for 90-100 fps cap, beyond which diminishing returns kick in and power bills continue to creep up.

Just use MSI Afterburner and do some tests. I also usually setup a fan curve where the fan always runs faster than default to keep the temps lower.
i use prime95 for cpus and msi kombustor for gpus. if they can run for a while without errors i keep my settings, otherwise i increase power/voltage and try again
prime95 isn't a very good test anymore. With the changeover from blend to smallfft, it doesn't test the frontend or the memory controller or any of the other parts of the CPU very well anymore, it loads the kernel into instruction cache once and then it just slams the AVX units as hard as it can.

so not only does this not test the rest of the cpu at all - meaning you can run into problems with other parts of the CPU that aren't stable at those frequencies, because they're not being tested because it's only running the AVX units - but it also doesn't test frequency/power state changes at all, so you can run into situations where as soon as you close prime95 and it drops to a lower p-state, it'll crash.

gpus have run into similar things with furmark and kombuster and other power-virus tests... actually the GPUs themselves will detect when they're running and throttle down, so they no longer even do the thing they're supposed to, but, gpus also change power/frequency states under real-world workloads, just like CPUs, and they don't under furmark/kombuster. this actually caused a crisis at the ampere launch... all the testing had been done with a "pre-release bios" that only allowed these sorts of power/thermal testing, and it turned out that while the chips might be stable at max p-state, they weren't stable when they shifted back to a lower p-state, or from a lower p-state back to maximum. That was the whole "POSCAP vs MLCC" thing.

prime95 and furmark were very very popular 10 years ago but that's where they belong, they don't do the job anymore these days.

>> my objective for the build was small as possible, quiet as possible, and as powerful as possible in that order.

With the same priorities and a deemphasis on graphics, I present to you the Mellori-ITX: https://github.com/phkahler/mellori_ITX

Uses the CPU fan as a case fan. By protruding through the top we get a lower profile than is possible with any other ITX case (well the standoffs can be cut down but that has not be optimized).

My next build will be an upgrade of the same design but with a Zen 4 or 5 chip with 8 or 16 cores depending what fits in the power constraints of the Pico-PSU. It will be a while though because that system is still more than enough for everything I do with it.

Mini ITX is also insanely more expensive than building a regula tower. Sure, if you're only putting the most expensive CPU and GPU in it then probably it doesn't matter to you but for value oriented builds, miniITX case, Mobo, PSU and cooler add up a lot.
You can get a great cheap ITX cases these days for about $50 (Cougar), A 650w SFX Power Supply for about $70 (Evga), ITX motherboards start at $110... then just make sure you choose a sensible CPU/GPU from there based on your power supply. And if you're using entry level cpu/gpu then you don't need to go crazy with cooling either.

Certainly not much more expensive than a regular mATX build imho.

I have an M1 gaming build where I prioritized efficiency; 5800X3D and RX 6600 with a 450W PSU.

I also have a mini-ITX Lone L5 build with an i3-12100 and no GPU with a 192W PSU. (Effectively - PSU is technically a bit more, but the AC/DC adapter is only 192W.)

What games can you play on an M1?
I think this is the nCaae M1, a computer chassis and case, not the Apple M1.
> A lot of people are undervolting their RTX GPU's because for an only about a ~3% performance loss you get about 10C less temp which translates to far less fan noise. I don't know why Nvidia doesn't just have a one click button for people.

Yeah, I did exactly that with my 3080. Dropped ~50W depending on the game and I was able to keep the same clock speeds.

Undervolting actually let me over clock my 3070 higher, presumably due to extra thermal headroom? I noticed two peaks in the timespy results and undrrvolting moved me between them, so this must be pretty well known.
They probably work on a successor. In the meantime, the DAN Cases A4-H2O or the FormD T1 are worthy replacements.
Yeah undervolting is always worth it.

You can also limit your i7 power usage, so no need to go for an i3 if you have the money.

And also use the heat from their PC to boil water and then spin a turbine to generate electricity to sell back to the grid.
For people who use resistive electric heating I've recommended them to run crypto miners on their computer. Same efficiency with regards to heating, but you can earn some extra money as a bonus.
I've done this to heat the small room I use as an office, its far more efficient than the shit electric radiator in there.

Rented house so can't do much about the absolutely useless heating setup.

I lived in a little apartment with resistive wall heaters and I did just that in the 2018 period. Even had some Raspberry Pis mining Aeon, a lightweight offshoot of Monero.
Not really even close. Even with a 235W CPU and a theoretical 600W GPU you wouldn’t actually exceed even half the capacity of a single 15A circuit in synthetic benchmarks that stress the system beyond real-world loads.
I think the issue is with older houses that might have 15 amp circuit breakers compared to the modern standard of 20A. One high end desktop computer by itself isn't likely to be a problem, but the way these houses are wired, there are a lot of outlets on the same breaker since they were mostly designed for lighting loads. Our 1950 house in MI will flip the breaker if we use the microwave, toser and bathroom vent at the same time, and my desktop is also on that circuit (with a UPS)
15A vs 20A is a factor of the gauge of the wires as well. You can’t just swap the breaker for a bigger one. You’ll get heat and depending where that could burn the house down.

I have a relative whose house burnt down due to stapled wiring in the attic. Thermal cycling eventually created a short. When your attic catches on fire the smoke alarms go off in time to save the people, but the moment the ceiling starts to cave in the entire house is involved and you’re mostly trying to keep the neighboring houses from burning.

Good callout. Yeah, I should be referring to the electrical circuit as a 15A circuit and not that it's just a limitation of the breaker.

We have the original fabric sheathed wire as well in the walls still which needs to be replaced to modernize the electrical system.

You have a 15A Fuse. You use a 12A Microwave, a 10A Toaster you have blow your breaker right there, and a 10A Bathroom vent?

if you run a separate circut for the Microwave, and separate your bathroom vent + your bathroom LED lights, you can run all of them at the same time with your toster. Running circuts is comparatively easy, vs installing a new 200A fuse box.

If you have bathroom and kitchen on single circuit you have bigger fucking problems than powering gaming PC, whoever did that abomination needs to be fired.
In 1950, that was probably seen as perfectly fine. I used to own a 1942 home that had 4 screw in fuses for the entire house.
For sustained loads you are only supposed to draw 12A, and the PSU has a conversion loss, dropping you to perhaps 10A of power for it all. Plus, then you can’t run anything else on the circuit.
10A is ~1200 watts. That's quite a lot.
It’s easy to go over when you start factoring in other things like monitors etc

A beefy CPU, GPU and a couple of high end monitors can take you to the edge of that and over.

> It’s easy to go over when you start factoring in other things like monitors etc

Why would monitors even be factored in? They shouldn't be on the same circuit anyway.

Why wouldn't they be on the same circuit? The monitor and computer are in the same room and would generally be plugged into the same outlet. I think this would be the rule rather than the exception.
That’s absurd. Most people will not only plug them on the same circuit, they’ll plug everything into a single multi plug feeding from a single wall socket.

I’ve never seen anyone, in corporate and home environments , split their circuit use like you describe.

253W (13th gen intel) + 450W (video card) + 2 monitors + a speaker system can easily hit 1000W.
Sure, you would be able to put smaller power draw items on the same circuit, but between the CPU/GPU/Motherboard/PSU/Monitors/Peripherals you will not be able to put two of these machines onto the same circuit.
For those confused like me, this conversation is about US circuits. On a typical European 230V 16A circuit, it's not a problem.
Maximum available power for standard domestic users is still only 3kW in many places. Might not be enough for a gaming PC, washing machine and microwave!
You would fit a gaming PC there?

I have a microwave (1270W) and dishwasher (2400W) on the same circuit (230V, 16A). It didn't trip yet...

230 x 16 = 3680 and 1270 + 2400 = 3670. Living on the edge.
Depends on your country, in the Netherlands 25A and 35A main fuses are common.
that's it?? that's not enough to even power an electric stove
Where, in deep russia ?

3kW is typical kitchen power.

In Italy it is very common. The wiring is normally rated for more (4.5kW) The power is limited at the counter switch.

> 3kW is typical kitchen power

Most stoves used to be gas powered. Now induction is becoming more common (but it requires an upgrade to 4.5kW).

A 15A circuit is good for 1440w sustained(120*15*.8), not 1800w.
If you have a circuit in your house that trips for “no reason” this is partially why.

With a steady load you can run a circuit breaker past the rated amperage on the breaker. But look at it funny and it will pop.

The most obvious case of this was when I knew someone who would plug a vacuum into a different circuit and blow a breaker. Just a little noise on the wires and click.

People often use power strips for their computer. So you also have your dual 4K LCD monitor system, as well as maybe plugging in a phone to charge as well which can have high peak power draws over USB 3.0.
I actually did this...I got two dedicated circuits put into my room - one for the window unit AC (no point in cooling the whole house when I really just need to cool this room most of the time), and one for my gaming computer. My work laptop, lights, etc. are all on the original main circuit of the house.

A friend of mine is an electrician so the price was very reasonable, and it has been worth it, especially during this hot summer.

I did something similar for my home lab setup in my previous house. It was pretty reasonable having two dedicated 20A circuits run w/ surge protected hospital-grade outlets and dual function breakers. Each circuit fed a different UPS which fed a different PDU so everything had redundant power back to the breaker panel, which was all I could reasonably do residentially, and it meant none of the servers/network gear impacted the rest of my office circuits.

It was reasonably cheap, and in my next house I'll do the same again. Running additional circuits is pretty easy if you have an attic or crawl space.

Are you exhausting the gaming computer to the outside or into the room you are cooling?
Into the room I'm cooling. I suppose it would be possible in theory to do so, but the particular layout of the room makes it difficult to impossible to exhaust both the AC and computer, I think.
In previous heat waves I've seriously considered venting my PC through the wall straight to the outside, but alas I currently rent.
Do you have an inroom AC unit? You could run a dryer hose from the back of your computer to the same window vent.
Ironically, I have a printer that really needs a dedicated circuit. When it warms up the toner, it draws 12 amps for 1-2 seconds.

Printing often pops the breaker. I had to move the printer out of my home office into a bedroom, but even then we've popped the breaker when printing while vacuuming.

(It's not a case of bad wiring, either.)

There are types of fuses that have a time delay on them for this purpose. A lot of electrical appliances have that kind of startup burst of energy. An electrician can tell you more
Warming up the laser printer (and its a small one) reliably causes the lights throughout my apartment to flicker.
It's not an AFCI breaker, is it? My last house had sensitive AFCI breakers that my laser printer would trip about a quarter of time when warming up.
Yes, my electrician was going to change it for me; but then I plugged my printer into a kill-o-watt and learned that it was pulling 12 amps.

I've been assuming it was current, because if it has the circuit to itself, nothing trips.

(My office only has one circuit, which is dedicated to the room. I could have asked for 20 amps, but it didn't occur to me.)

I used to own a brother laser printer and it did this, I switched to HP LaserJet and this no longer occurs.
who cares about these russian gas problems. I will have to throttle my cpu so it doesn't get too hot in winter
My office gets about 5c warmer when I play games on my PC, despite being poorly insulated with the window open.

And I've only got a 3900X+2070 Super...

feeling a bit cold, gonna turn on my gaming pc for an hour
Water cooled? More like water heated, amirite?
253W is only 2 amps in the US, thats like 10-20% of a breaker’s capacity
Peak draw for even a current-gen graphics card is well over 500W. There are rumors that a 4090 will need as much as a 1500W power supply to run it. That's almost a complete 15A circuit just for the PC once you factor in cooling, speakers, monitor etc.

I already have issues where the breaker would pop with my current gaming PC if it fully spins up and I had to get a 20A circuit put in to handle it (mostly because there is more than one computer on the circuit).

There are cards like that.

But you don't have to buy those cards. I play my games in QHD on a Radeon 6700XT 12GB, which tops out at about 165W.

I can't lie, the idea of needing a 30amp dedicated CB makes me feel happy as a nerd. Makes my power company happier..
With the GPU it's going to reach 51% at this rate. That's all it takes to require one per computer.
Just realized everyone's gonna have to turn their power targets down when running a LAN party. I gave my brother my old 2080ti, something would coil whine when he played Battlefield. We turned the card's power target down until the whine went away. We found at 35%, the whine stopped, and the performance difference was not easily discernable with a basic FPS counter just flying around a MP game.

Opportunity for software that dynamically adjusts CPU and GPU power targets in the middle of various games, learns the game's power/performance profile and whether it's CPU/GPU bottlenecked, and optimizes perf/watt while maintaining a given FPS target?

That's what Radeon Chill is.
I believe the new 4x nvidia series uses 450-500W.

Throw in 2 monitors and a speaker system and you're coming close to overloading your 15amp breaker.

For those of you unaware, most households in the USA have 15amp circuits for their wall plugs. With that you can safely pull about 1200Watts constantly.

I am unsure what the normal household circuit amperage is in the EU or elsewhere...

Max sustained load on a 15A breaker is not 10A/1200w, it’s 80% of 15A at 120v, or 12A/1440w.
The normal amperage in Germany is 16A at 230V, with a peak load of 3500W and a sustained load of 3000W.
I had a LAN party at my house in 2012 and one lunatic brought his 1KW+ PC and tripped a breaker which has seemed really twitchy ever since.
Circuit breakers do degrade after being tripped. Once usually isn't enough, but repeated tripping will wear them out.
You should have an electrician check the wiring too. You might be leaking a little current due to decaying insulation.

If you have to wire a room, ask for a larger gauge of wire so have the option of a larger breaker if you want it.

Already there in Europe... I actually prefer getting the Steamdeck out than turning the main computer on for "light" games.
This is the definition of “working smart vs. working hard”. Not everything about the CPU needs to be solved by pushing it to the limits of physics. TDP is not linear relative to CPU freq.
...no. Average EU circuit is 230V/16A, that's 3.6kW

Even if you ran 1kW (...somehow) you could still connect 3 of them and still have 600W left for audio/monitors.

We usually only use that high amperage fuses on high power appliances, like ovens or workshop equipment from my part of Europe.

I would say it's more normal to be fused to 10A for most indoor things, anything else is not normal, as most home appliance power cables are not even thick enough to carry the 16A 230V power safely.

You're right, I was being North American-centric, which is 120V/15A and could only run a single 1000W machine.
I popped the breaker when I accidentally connected my gaming computer and my car charger (plug-in hybrid) to the same circuit.

Probably would've been fine if it were a 20A circuit and not a 15A, but it did remind me how much power these things draw...

Or with power in SF averaging 40-ish cents per kWh a standard evening gaming session can easily cost a non-negligible amount of money.