Up to 600 watts of power for graphics cards with the new PCIe 5.0 powerconnector

https://www.igorslab.de/en/up-to-600-watt-power-for-graphics-cards-with-the-new-pcie-5-0-adapter-nvidias-rtx-3090-ti-makes-the-start-exclusive/

by jsiepkes • 5 years ago

86 176 5 years ago

igorslab.de

avian• 5 years ago

Why does the author/publisher feel the need to overlay their own logo over drawings they copied from someone else's datasheet?

skhr06802• 5 years ago

If someone wants to copy and paste his article, they’ll at least have to go to the effort of finding the images themselves

szszrk2• 5 years ago

But it clearly suggests it's his work. It isn't. Let the original author worry about how he protects his own work.

causi3• 5 years ago

To hide the fact he's violating Amphenol ICC's copyright by using their images and stripping their copyright notice and publishing info off of them.

noobermin10• 5 years ago

I'll be honest, it's very hard for me to imagine what I would do that would demand anywhere near 600 watts for a graphics card alone. I mean my PC can draw at most 120 watts and that feels like a lot, although the PC is pretty old by now. All of this for crypto? How many games are there out there that draw anywhere near this level of wattage just for graphics?

masklinn• 5 years ago

How many games are there out there that draw anywhere near this level of wattage just for graphics?

Pretty much any “AAA” game at 120+Hz, high resolution, with image quality cranked up.

I’ve had friends who managed to snag 3090s at prices they found acceptable (sic…), and had to change psus because theirs were a tad short (despite being theoretically ok going off of nameplate capacity, though it’s also possible the rails distribution was off). They were rebuilding gaming rigs, no crypto there.

Technically the 2x8 / 1x12 setup of the 3090 is off-spec, these are not officially supported PCI configurations.

nikanj• 5 years ago

90% of this for crypto, the rest for ML and games

ksec4• 5 years ago

4K Gaming at 120FPS with Ray Tracing would easily push pass 300 to 400W. Even on a hypothetical 5nm GPU.

noobermin10• 5 years ago

Ok, this is a tangent, but this kind of stuff irks me. Is there no love anymore for making things pretty enough but actually keeping things efficient? Do game devs (even AAA people) not like the family of things like 0x5F3759DF anymore?

Efficiency aside, simply pushing the power requirements doesn't even bring home the bacon. Nintendo's "lateral thinking with withered technology" works super well, just look at the switch compared to any of the consoles of its generation. I know PC gaming is different but even there people dig streams of undertale over cyberpunk (although cyberpunk had issues...), so not everything is pushing power requirements.

Literally, if all that matters is "realism" and "power" and pushing that boundary is an end in and of itself, well that boundary is already pushed by others. I mean may be not with a GPU but I work in HPC and I'm sure as hell my simulations draw more than 600W. So, this is a push for power in games specifically and that just starts to draw out my boomer side and wonder why people just don't try to go back and optimize their code first.

httpz2• 5 years ago

I doubt it's for crypto though. Running two cheaper 300W GPUs will be more cost effective. Also serious miners already moved on to ASIC anyways.

m463• 5 years ago

Seems to depend on the coin. There are lots of coins to mine/etc with a gpu.

thow-58d4e8b• 5 years ago

Ethereum is mined with GPUs. The total mining rewards (block rewards + fees) are actually marginally higher for Ethereum than Bitcoin, with both around $51M per day

junon3• 5 years ago

I do photogrammetry. That's one use that will max out the entire system (not just the graphics card) for hours on end that has nothing to do with games or cc's.

Just as an example.

noobermin10• 5 years ago

600W worth of photogrammetry?

salawat• 5 years ago

What in particular are you doing with it? I have the feeling my question may be a bit light on details for you to be able to formulate a great answer, but are you doing things like doing test renderings of an interpolated viewpoint given multiple integrated perspectives? Edge detections? Object "identity" detection (x, y, z) object in perspective W is (a, b, c) in perspective D? That sort of thing?

I could see how that could end up getting very computation intensive very quickly! Building up the 3-D space, tagging spots where the math doesn't quite work out... Compensating for different lighting conditions from different pictures at different angles to get just the info you're looking for!

Or am I completely off base?

3np• 5 years ago

Yeah, just wow. Here's what I run fine even under load behind a 600W UPS:

  * 15-20 arm64 SBCs 
  * 5 Ryzen nodes
  * a handful of HDDs and a decent number of SSDs
  * an enterpriseish 48-port PoE switch using 10GBE on some ports
  * 5 x86 SBCs (routers)

That's a crazy amount of energy for one GPU used for gaming.

ur-whale• 5 years ago

All of this for crypto?

ML training

dragonwriter• 5 years ago

How many games are there out there that draw anywhere near this level of wattage just for graphics?

Well, since its the brand new, top-of-the-line connector, hopefully very few current applications will max it out.

bick_nyers• 5 years ago

Gotta think about the scale here. 4k gaming pushes 8 million pixels, 60 times per second. Those pixels are being calculated from light bouncing off of meshes, each formed of 10,000-100,000 triangles. More triangles makes your objects look smoother and rounder. Each triangle also has texture information that dictates its color, as well as some specific properties such as reflectiveness. To achieve highly-realistic video games (and CGI), you simply have to have that level of complexity. Even then, the way light is calculated in video games is not realistic at all, it is done that way for significant performance/efficiency gains. Ray tracing is now being added, which is how light behaves in the real world, but that cranks the computational complexity through the roof. That's why it takes thousands of CPU cores 25 hours to render one single frame for a Pixar movie, they go for realistic physics/light.

MrFoof• 5 years ago

Just built a system that I managed to get a 3080Ti for at MSRP. I’ve spent a lot of effort to have it be silent (and extremely cool) with just air cooling, even when it does play games.

With a 5900X (slight overclock for max boost at 5.1GHz), some lightly overclocked 64GB of DDR4 memory, two 27” 1440p displays, a phone dock, KB, mouse, web cam and condenser mic it idles at about 150W.

General productivity, like development with a few VMs spun up, and maybe watching a 1080p video in the background? Maybe 180W.

Streaming a game. So I’m capping myself at 1080p60, which does not stress the 3080Ti with all settings maxed out. Two LED light rings also on, plus an LED pendant lamp. Now we’re squarely in 350-400W land for the entire setup.

Not streaming. 1440p, capping at 120fps (displays go to 170Hz). If settings are cranked up on a very recent title and I’m GPU bound, this is where the GPU alone can actually hit 400W by itself in some scenes (usually 280-350W) and the total power consumption for the room maxes at 600-650W.

—- ——-

There’s 6 140mm PWM case fans, the CPU has two 150mm PWM fans, and the GPU has three 92mm PWM fans. Case is all steel with sound deadening foam on both side panels. In every settings it’s silent unless I’m “going for broke” at max quality for averaging 120fps, where it’ll then be a “light whirr” once it’s heat soaked, which I’ve measured at 24.8dBA at 3 feet (~92 cm). GPU peaks at 76C, GPU memory peaks at 70C, CPU is around 65C, and system memory at 35C. All air cooled.

—- ————

Here’s the thing. Come next year, it’ll be a 32-core Threadripper with 256GB of memory and a NVMe RAID 10 array for real work with Spark without constantly paying by the hour. The CPU, storage, and system memory alone will probably pull 500W under max load factoring in the displays, KB and mouse. Still will idle close to 165W though.

jscipione• 5 years ago

This is still nowhere near as elegant as Apple’s MPX connector which eliminates the extra cabling altogether.

resist_futility• 5 years ago

I would rather pay for a $10 cable than 100x that for a motherboard

soylentnewsorg2• 5 years ago

It's not, because if you plugged a device needing 600W using an MPX connector, it wouldn't work at all, since MPX can only do 500W.

Here's the thing. When you have a lot of amps, they create noise in wires next to them. They'll also need thick wires and will get hot. When you have a lot of volts, they'll go through shielding and start a fire.

Do you really want to place something with a lot of amps and volts next to something that's transmitting timed high-bandwidth data, like a graphics card? Or run the entire output of your big PSU box that needs a bunch of fans, through the motherboard? For a tower form factor?

The single slot for power and data is convenient for phones and laptops. Not something that's 600W and is going to power a space heater in its next kilowatt+ iteration.

dingaling• 5 years ago

Given the RF noise and the heavy-duty electrical engineering, wouldn't it be better to isolate the GPU in its own external enclosure?

dvdkon• 5 years ago

That connector is really long and wouldn't fit in a number of cases (ITX PCs, servers...). For carrying lots of current, thick cables are just better than PCB traces (especially on PCBs that are mostly designed for signal integrity, not carrying power).

ksec4• 5 years ago

This is long overdue, for something I have been questioning since 2016. ( Our GPUs are severely TDP limited )

It is also interesting on one hand you have Apple pushing CPU and GPU integration for maximum efficiency. Where Apple could make a potential 300W TDP SoC for their Mac Pro. On the other hand you have CPU pushing to 400W ( and higher in the future ) while GPU pushing to 600W.

httpz2• 5 years ago

Assuming you can install two GPUs using 600W, that's basically running a hair dryer in your desktop since most of the energy is converted to heat.

oatmeal_croc• 5 years ago

Well, all the energy is eventually converted to heat.

ksec4• 5 years ago

This got me thinking. ( I must be missing something or having wrong assumption in my high overview of the issue. )

Do Crypto People use their GPU generated heat as heater assuming they lives in a place that requires heating anyway?

Doesn't that equate to free money assuming they could actually mine crypto?

faeyanpiraat• 5 years ago

Heating with a Heat pump or Gas is significantly cheaper, so if you look at the big picture, it’s not “free money”.

saberdancer• 5 years ago

Yes. That's one of the benefits.

Some people use electric heating even without crypto so using GPUs to mine crypto to get the same effect is a no brainer.

Problem is that during the summer you have to get rid of the excess heat, so you need air conditioning or perhaps open air cooling.

Not gonna lie, I've used my GPU to heat up my small room before.

i21QMgplhRJs2OL• 5 years ago

Check out this video on using the heat from computing beneficially.

https://www.youtube.com/watch?v=hNytmvltsWk

noobermin10• 5 years ago

Why is this being downvoted? If you have a kilowatt (I wanted to type that out instead of write KW to emphasize it) coming out of the wall that energy has to go somewhere. Literally warm your room during winter and turn down your heater.

worrycue2• 5 years ago

And make your AC work even harder during summer or if you live in a tropical/desert/…etc. climate.

jakogut• 5 years ago

Most? Where does the rest go?

denton-scratch8• 5 years ago

All of the energy is converted to heat. Some energy from your rig is emitted as light; but that's your monitor, and your monitor has its own power supply (which means that 600W is an underestimate).

worrycue2• 5 years ago

The RTX 3080 already uses 320W (peak?). By next GPU generation who knows.

Good lord, just 2 generation back GPUs like the 1070Ti consumed 180W. Even if you add a CPU (of that era) like the i7-7700 with it 65W draw, that just 245W. Now a video card alone can draw more power.

lostmsu• 5 years ago

I have a 2xRTX 3090 rig under desk. At close to full GPU load the temperature on the desk is about 3F higher than in the room.

BeFlatXIII• 5 years ago

It helps save on the winter heating bill if you live in Wisconsin.

jl6• 5 years ago

I’ve always thought of gaming as a virtuous low-impact form of entertainment, insofar as it displaces real-world pursuits like foreign ski holidays, gasoline-powered road trips, or land-hogging golf courses.

But burning nearly a kilowatt on a gaming rig feels like a step too far. Sure, the power could be sourced from wind or solar plants, but there’s still a level of excessive conspicuous consumption going on here that doesn’t sit right with me.

DeathArrow2• 5 years ago

Any human endeavor consumes energy.

dotancohen2• 5 years ago

Sex is good for 100 calories per minute. Google tells me thats a bit over 5 watts.

sz4kerto• 5 years ago

It's really low impact though. Even if your rig consumes a kW, you're still not driving anywhere (in a car that consumes at least an order of magnitude more), or going out to a restaurant (that's air conditioned), etc.

nuerow2• 5 years ago

It's really low impact though. Even if your rig consumes a kW, you're still not driving anywhere

If google didn't failed me, a good car mileage is equivalent to around 20kWh per 100 miles. Therefore, a 100 mile drive is loosely equivalent to a day or two gaming with one of these rigs.

turtlebits3• 5 years ago

Lots of things are a huge waste of electricity. Ever use your oven? At 12% efficiency you're wasting over 1kw of electricity.

Unless energy prices rise, it's literally pennies.

noja• 5 years ago

This line of argumentation drives me insane, and it's so pervasive right now.

Why should I walk to our friends' house down the road? After all, I drive to work, so why not drive there too?

Why should I use less plastic? After all, I already use some plastic, so why not use more?

Why should I eat less meat? After all, I already eat some meat, why eat less?

denton-scratch8• 5 years ago

How can an electric oven be just 12% efficient?

I suppose:

1. You often have to pre-heat the oven, so during that time, you are not cooking food

2. The oven is rarely full, so instead of heating food, you are heating the oven

3. The oven remains hot after the food is removed, but you could argue that's low-grade heat, unsuitable for cooking

If my electric oven is just 12% efficient, I'd like to know why (and how I can get one that is more efficient). I understand that microwave ovens are much more efficient (I guess because the heat is generated inside the food). But they're no good for browning food, or baking bread.

I'm still lost on this notion that an electric oven is just 12% efficient. If that's true, then I could patent a device that harvests energy from electric ovens, and make a mint.

rowanG077• 5 years ago

Rest assured that almost no gamer will have a card that uses that much power.

tiotempestade• 5 years ago

Exactly why I decided to comment, only to find you already touched the topic :)

This is getting out of control!

Nvidia/AMD: build more efficient GPUs!

unglaublich• 5 years ago

Why? Your home heating consumes 5-50kW. In colder climates, the power consumption will be compensated by less home heating.

bestouff• 5 years ago

if you compare that with an inefficient electric heater. Otherwise, your gaming gear will consume way more electricity for the same heating power than, say, a heat pump.

tgv• 5 years ago

Even if, in warmer climates the offset will be doubled by the AC.

fomine3• 5 years ago

5kW minimum, seriously? Not 5kWh/day?

evandijk703• 5 years ago

Definitely agree that a kilowatt seems very high for gaming and starts to have an environmental impact. Still, driving a car at 100kph takes around 20 kW of power, so driving somewhere is still a bigger burden on the environment than gaming.

noobermin10• 5 years ago

That's peak power. You don't run at 100kph straight for hours but you will run your gaming rig at say 500W for three hours in a day (particularly for people willing to shell out money for such a gaming rig). The total energy per day might not be that different, you'd have to account for how much is involved in commuting in traffic.

jayd163• 5 years ago

Probably not worth judging the entire sector by the peak theoretical output of one connector that might be relegated to industrial use.

chaosbutters314• 5 years ago

if you crunch the numbers on how much solar (desertec has a fun graphic on this for the interested) and wind power we could produce if politicians actually cared about fighting climate change, there is nearly an infinite supply of power for humanity.

This isnt even including fossil fuels, nuclear/fusion, biomass/trash, and hydro.

https://en.wikipedia.org/wiki/Desertec#/media/File:Fullneed....

Raidion• 5 years ago

Lots of sunlight, but limited amounts of manufacturing and rare earth metals for solar and limited amounts of energy storage for times when solar and wind aren't available. Solar and Wind are terrific, but they're not a free lunch. What drives down the price of energy, drives up the cost of wind/solar/batteries.

stefan_2• 5 years ago

It's a trivial amount of power and even better, we have already electrified all the components! Computers don't require us to go out and replace all the combustion engine vehicles still around. Clean up the grid and that's it.

nitrogen2• 5 years ago

excessive conspicuous consumption

Energy is a proxy for accomplishment and development. Humanity's #1 goal should be to maximize energy use per capita while minimizing energy use per activity, such that every human is doing as many desirable activities as possible.

Gaming at 1kW for an hour costs 30 cents or less in electricity. As others have mentioned indirectly, going for a Sunday drive to see the changing leaves uses more energy. A space heater uses more power.

stirfish• 5 years ago

minimizing energy use per activity

Maybe this is what feels off?

A kilowatt feels like too much for a videogame. This isn't a bitcoin mining thing, is it?

hulitu• 5 years ago

Why so negative. I think gaming is the future. We can heat houses and have fun. If only will be able to store the heat. Why make better chips when the user do not care ?

dragontamer• 5 years ago

But burning nearly a kilowatt on a gaming rig feels like a step too far.

How much energy does a golf cart use? Cause those golfers are using a golf-cart for miles when their legs are perfectly acceptable (and golf-carts are illegal in professional play)

DeathArrow2• 5 years ago

I wonder what will be the MSRP for 3090 TI and what the actual price in stores would be. Even mid tier GPUs like 3070 cost a lot of money.

JohnWhigham• 5 years ago

The 3080 Ti is north of $3k, so...even more north of that.

bob10293• 5 years ago

Everyone tries to be fancy with wiring exotic networking in their homes, but the real performance kings are installing NEMA 14-50R in their offices right now.

neither_color• 5 years ago

Anecdote: A relative of mine who does home remodeling told me that over the past year most of his clients plan for dedicated office rooms now, rooms that would've been planned as guest rooms and whatnot before. They're also running 12-2 wire with 20 amp breakers to these rooms now. So yeah, not quite the laundry plugs you're describing but getting closer.

Faaak• 5 years ago

It's funny because here in europe, power plugs with 16A (some are 20A) are actually the norm: at 230V they can deliver 3600W/4600W !

bartwe• 5 years ago

We're going to see laws dictating max wattages for consumer computers real soon.

Tenoke• 5 years ago

'California's Energy Consumption Tier 2' is basically that but I believe it applies only to prebuilds currently.

timw4mail3• 5 years ago

This looks like some abomination of the ancient molex drive connection with part of an ATX main connection.

At which point does the GPU get its own dedicated power supply?

AnIdiotOnTheNet• 5 years ago

We seem to be reaching the point where I expect it'll soon make more sense to consider the GPU as the heart of the computer and the CPU as a peripheral.

cesarb2• 5 years ago

Isn't the Raspberry Pi already there? IIRC, its main core is the GPU, and the ARM cores are one of the peripherals.

kevingadd2• 5 years ago

Historically typical GPU power draw has exceeded CPU draw for a really long time. In terms of peak compute throughput the GPU usually has an advantage in any gaming-focused machine, and even general productivity ones. A developer workstation with a Threadripper probably evens things out more.

A GPU these days can often do general purpose compute, but not in a way that meaningfully allows it to compete with the OS for heavily branched or random access workloads since its memory controller and execution model are a poor fit. I'm not sure we'd ever see GPUs fully displace CPUs for that reason.

belter• 5 years ago

The CPU is a peripheral ;-)

(See Slide 5): https://papers.put.as/papers/firmware/2014/2014-10_Breakpoin...

scrooched_moose• 5 years ago

Will Smith (of Tested/Maximum PC) mentioned in one of his recent podcast episodes [1] that GPU vendors tried to add dedicated power supplies to cards, with their own AC connection, a while back (mid 2000s or so if I remember right). Consumer/industry pushback killed it before they hit shelves and the vendors focused on efficiency instead. I don't see the same pushback happening these days.

1) https://techpod.content.town/

fredoralive• 5 years ago

I think the mad 4 processor 3DFX Voodoo 5 6000 that was never released used an external power supply, at least on some PCB revisions.

I'm not sure if any released graphics card has used their own power supplies. I think they all used some sort of internal connection to the standard power supply if the slot can't power it alone.

vmception2• 5 years ago

At which point does the GPU get its own dedicated power supply?

This is true in many machines already for several years, if you look at the machines the hard to find GPUs are actually in.

I wouldn’t be surprised if that is a market force behind this new PCIe standard.

nitrogen2• 5 years ago

Yeah, I was recently looking for an ATX motherboard extension cable to hack apart for an evening project, and all the results were for splitters to connect extra PSUs to the mobo's Power On signal for mining rigs.

stefan_2• 5 years ago

Why would it ever? It's much more efficient to scale up the one AC mains voltage -> 12V DC supply you already have.

You think in datacenters they are just stacking up PSUs? No, all of this stuff gets vastly more efficient and reliable if you can build just one big PSU to supply say 48V DC and distribute that everywhere.

timw4mail3• 5 years ago

My understanding is that most normal servers have their own PSUs, and often a hot spare. But that's not really relevant.

The question was more rhetorical than serious.

cogman10• 5 years ago

The real question is at what point do gamers start choosing lower power parts because the GPU is too power hungry? Do we get into a world where professional gamers start having 240V lines installed for their PCs?

A US power outlet is typically rated at 120VAC@15A, that's a 1800W budget if the only thing on the circuit is a PC.

kevingadd2• 5 years ago

Well, the higher power draw cards tend to be more expensive, so in practice budget-focused gamers are already buying lower power parts.

AMD and NVidia have at times competed on power usage, but generally that doesn't sell units to the degree that game support or new features do.

For mobile you start getting traction there because '<vendor>-based laptops have an hour of extra battery life' is meaningful, but gamer laptops are typically designed to be plugged in. The higher power draw typically means more heat and louder fans as well but for some reason noise doesn't seem to be a consideration for most gamers - every gaming laptop I've ever used was unbearably loud.

crest• 5 years ago

http://tdfx.de/ger/voodoo_volts.shtml

brenelson• 5 years ago

It doesn't make any sense. Why do you need to have 600W to power a graphics card? Why do they need an independent power connector?

gambiting• 5 years ago

I'm not sure I understand your question, but I will try.

>Why do you need to have 600W to power a graphics card?

You don't. There is no GPU currently that needs that much. But as cards are comfortably approaching 400W and more, a new connector is necessary so you don't end up with GPUs taking 3 or 4 existing PCIe 8-pin power connectors. This single 55-amp compatible connector allows for significantly easier routing of paths on circuit boards.

>Why do they need an independent power connector?

Because the PCIe slot alone can only provide 75W of power. And if it could provide more you'd need to provide that power to the motherboard so you just moved your connector from one place to another.

nottorp3• 5 years ago

This is insane. Give me back the 75W GPUs instead. No extra power connector, just the slot.

bruce343434• 5 years ago

APUs/integrated GPUs have taken up that role.

nottorp3• 5 years ago

But I don't want a shit CPU. I can buy a 65 W 8C/16T CPU from AMD (which I need for more productive purposes). Why can't I pair it with a 75 W video card? Should be enough for 1080p gaming.

sp3324• 5 years ago

It's been a few years since the release of the GTX 1650 but it's still a pretty serviceable card. Cheap, too.

nottorp3• 5 years ago

That's the point. Where is the 3050?

denton-scratch8• 5 years ago

600 watts? That's one bar of a two-bar electric fire; in my youth, that two-bar fire was the only thing keeping some families warm.

I mean, that power all gets turned into heat anyway in the end; so sure, if you need more heating, forget the two-bar fire, and buy a graphics controller instead - playing games with the two-bar fire isn't a good plan.

I don't get why they can't make efficient GPUs. I mean, I do get that graphics depends on computation, and that all computation has an intrinsic minimum energy cost; but half a killowatt, to make a moving picture? That's more than the power supply for my gaming rig (which I retired, because the fan noise was excessive).

MrBuddyCasino• 5 years ago

I don't get why they can't make efficient GPUs

They do make efficient GPUs, see smartphones. Even current desktop cards are efficient considering their computational power, but they are increasingly tuned to run with higher power budgets. Turns out people care more about FPS than power consumption I guess? Also consider that winning the performance crown has a halo effect for the rest of the portfolio, so the performance / high-end models are tuned towards that.

metalliqaz• 5 years ago

I agree it is a little out of control.

Some may marvel at the incredible power available to consumers now, but I've been watching with disappointment at how each new generation is only very slightly better in the performance per watt metric. Most of the new compute power is coming from increased energy draw. In an energy-conscious environment it's quite hard to justify.

sp3324• 5 years ago

GPUs are efficient. That's why (some) people get benefits from throwing lots of power at them. If there were a smaller difference between a 200W part and a 300W part, fewer people would upgrade.

denton-scratch8• 5 years ago

I do appreciate that!

It just seems seriously counter-intuitive to claim that spending 600W to put a moving colour picture on a screen the size of a bed-pillow counts as "efficient".

[Edit: obviously it doesn't take 600W to play back an HD movie - the energy is being spent on game computations, or hashing, or something like that]

myself2482• 5 years ago

That looks all the world like a Micro-Fit 3.0 drawing, whose contacts are normally rated at 8.5A, but here they're claiming 9.2A each. Also, the largest Micro-Fit terminal is made for 18AWG, but the article mentions 16.

https://www.molex.com/molex/products/family/microfit_30?pare...

I suspect what's happening is Molex is making a new version of the terminal with higher clamping force or better plating, to keep the temperature rise down at higher current, and larger wire grips, to accommodate the thicker conductor. (This will also allow more heat flow away from the contact.)

However, the contact pitch is unchanged from 3.0mm, meaning the cavities in the housing can't grow any more, so the wire insulation thickness will be limited. That's not a big deal electrically since it's only 12 volts, but it's a consideration mechanically since the wires will be less protected against abrasion, pinching, and other damage.

LeifCarrotson• 5 years ago

The current deratings are down to 5.5A for 12-circuit wire-to-board applications:

https://www.molex.com/pdm_docs/ps/PS-43045-001.pdf

But that is allowing a maximum temperature rise of 30C, it uses 18AWG wire as you say, and it's supposed to be capable of 600V AC/DC; it's not supposed to decompose/leak more than 5mA when exposed to 2200V.

All of that is overkill for inside of a PC. If you're willing to limit the operating voltage to 12V and can guarantee that your board side conductors have big, multi-plane copper traces pulling heat out of the contacts to an actively cooled heat sink, you can get away with a lot that you couldn't if you were using the connector as, say, an in-line disconnect in some conduit for a 480V servo drive.

xxpor• 5 years ago

At what point would it make sense to move to a 24v or 48v power standard in PCs? The dc-dc conversion world has improved a lot since ATX was invented.

myself2482• 5 years ago

48v made sense years ago, the only reason we haven't done it is inertia. You're spot-on; the PSU is not making voltages that're directly used by components anymore, with the possible exception of 5v for USB and stuff. Everything else has a local DC-DC converter and the "12-ish" is used as an intermediate distribution standard.

Pursuant to that, the ATX12VO standard is a huge step in the right direction. It ditches the 5v and 3v3 rails from the PSU and uses 12 only. This requires only modest changes to peripherals, most of which were getting most of their power from the 12v rail already.

I think it's an excellent stepping stone on the way to an ATX48VO or something. That will require some more changes because a lot of popular power semiconductors are only rated to 30v or 35v or something, so there will be some push for a 24v compromise, but I think the efficiency gains with a higher voltage will ultimately win out.

kayson• 5 years ago

I've always wondered why CPU AIO coolers are so prevalent, but GPUs almost exclusively use air coolers. We're nearing a point where GPUs will have a TDP >2X the hungriest CPU (Threadripper), but the cooling used by most is far less effective.

It's especially noticeable in smaller builds like those using mini-itx. Most of them GPU coolers draw air in from the bottom and exhaust out the sides, which doesn't really fit well the usual PC case airflow setup of draw cool air in the front and exhaust out the back and top. It seems like blower style coolers are also getting harder to find.

I'm hoping my next PC can have an AIO at the intake connected to the GPU, and a large air cooler for the CPU. That makes way more sense to me than having the AIO on the CPU and an air cooler on the GPU...

ajoy39• 5 years ago

The difference is that with GPUs nearly every model has a different layout of components around the actual chip, and those components need to be cooled too, so making a universal cold plate for them can be really challenging. The AIO I bought for my last computer could be used with any CPU, AMD or Intel, released in the past decade. The water block I bought for the GPU I put in my desktop two computers ago could only be used with reference designs of the AMD R9 290 or 290x.

There are models of GPUs with AIOs, EVGA makes their Hydro series, Gigabyte has their waterforce series. They just usually aren't worth the cost since you have to design a new full cover block not just got every generation but also usually for different cards in the same gen too.

Lastly, TDP is not a defined standard and each manufacturer defines it differently. Intel for example defines TDP as the maximum allowable power draw under full load. How that translates to actual heat output depends on architecture and process node. Intel's most recent chips for example all max out at just over 100 watts TDP, but they're known to need 200+ watts of heat dissipation for sustained workloads.

sbradford26• 5 years ago

A big part is that CPU sockets are very standardized and you are only cooling the CPU and not the memory and power regulators. For graphics cards the coolers need to cool the gpu along with the memory and power regulators which can be in different places depending on the manufacturer. This usually means you need a block made specifically for your model of card. You can buy those blocks and do custom water cooling but the cost of that is incredibly high. Also it finally comes down to the AIO coolers really aren't better than good air coolers. Sure AIO tend to be quieter and move the heat to a different location but on pure performance they don't crush air coolers.

Up to 600 watts of power for graphics cards with the new PCIe 5.0 powerconnector

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