Comment by neogodless | Hacker News Reader

Comment by neogodless | Hacker News Reader

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It's not all bad.

> On the face of it, the Core i9-10900K with its ability to boost all ten cores to 4.9 GHz sustained (in the right motherboard) as well as offering 5.3 GHz turbo will be a welcome recommendation to some users. It offers some of the best frame rates in our more CPU-limited gaming tests, and it competes at a similar price against an AMD processor that offers two more cores at a lower frequency.

If you don't mind your CPU drawing 254W of power.

> For recommendations, Intel’s Core i9 is currently performing the best in a lot of tests, and that’s hard to ignore. But will the end-user want that extra percent of performance, for the sake of spending more on cooling and more in power?

In my experience, I prefer cool running hardware as much as possible. I don't need the absolute most powerful if the costs, heat and noise are going to move the balance too far.

But I hope we see Intel succeed in improving their process and innovating a bit more instead of just shoving more cylinders in the engine and adding nitrous.

Disclaimer: Happy AMD Ryzen CPU owner

The whole situation is reminiscent of the FX9370, where AMD didn't have a new architecture yet and just cranked their existing chips up to insane amounts of power draw to eek out the last bit of performance.

Of course, the 9370 had all sorts of memes about how it would catch your house on fire. I wonder if the i9-10900k will have the same.

Hopefully, like with Ryzen following up on the 9370, the next line of chips from Intel after this will be game changers.

Please someone correct me if I'm wrong, but AFAICS the core voltage of the i9 1,52V. So with 254W, that thing really draws 167 amps? I guess every μΩ of resistance counts here or the board just explodes?

That's already been a problem for a long time. When CPU speed changes the transient currents are ridiculous, and the dI/dt is bananas, too. This is one reason why a few generations ago Intel had to go with a fully-integrated voltage regulator. The mainboard people were unable to build good, efficient VRMs off-chip.

Maybe its not possible to regulate such a high current at gigahertz speeds off chip? The board traces and pins might have inductance high enough to negate smoothing capacitors at these speeds?

Yeah I mean there's no way a part on the other side of a CPU socket is doing anything in the gigahertz range. Those frequencies are covered by layers and capacitors in or on the package itself. What's hard about modern VRMs is being able to step from Icc(max) to zero while overshooting < 25mv, or the forward load step from nothing to ~200A in an instant without dropping. The specs are in Intel's VRxx docs (eg VR13).

> I guess every μΩ of resistance counts

More importantly, every μH of inductance counts. Running 200 A into the chip is not that difficult, the real difficulty is the high di/dt - how to maintain a nice regulated voltage when the current consumption suddenly raises from 10 A to 200 A within a few microseconds.

> μH

It's a typo, should be nH. 1 μH is a huge value.

They do. CPUs tend to run at pretty high core voltages to achieve their high clock speeds compared to GPUs, so GPUs consume even more current: 300 W at ~1 V = 300 A.

In AMDs case the CPU is supplied with a common core voltage that's regulated by a per-core ultra-fast LDO. There is also a power capacitor (mimcap) on the core die.

can someone calculate the watts/meter^2 on this chip, for science?

Eyeballing the chip, it looks like ~5cm^2? This would mean it puts out 500,000watt-meter^2 or about 50 times the heat of the surface of the sun. Do we have cameras fast enough to see this explode if the heatsink falls off?

>This would mean it puts out 500,000watt-meter^2 or about 50 times the heat of the surface of the sun

Where are you getting this figure? A random website[1] says the heat on the surface of the sun is 62,499,432 W/m^2.

Also the die sizes are on page 2: 198.4 mm^2 for the 10 core part. Divide the total power (254W) by that and you get 1,280,236 W/m^2.

[1] https://www.pveducation.org/pvcdrom/properties-of-sunlight/t...

excellent thanks! And no that number was from a random website :) . Looking at it, I think its solar radiance at earth surface. 1000 watts per meter is way too low donno what I was thinking

This is the CPU power density infograph you are looking for. https://i0.wp.com/semiengineering.com/wp-content/uploads/201...

Its pretty funny that after 20 years we're off the right side of this graph by 100X right? Current chips are somewhere between "internal combustion engine" and "surface of the sun"

Oof, that CPU is going to be hot on full load. I imagine running an air-cooler is impossible on that one, making this a no-go for me.

The Prescott era chip used to get complaints about the amount of heat it produced. "PresHot", "Toaster" etc were slung about. A quick bit of searching dug up that it used to have a TDP of 115... and now we're talking about chips that more than double that. Yikes.

Prescott had one core though, this has ten. 115W was with an order of magnitude fewer transistors. Even back then, that was terrible performance.

The TDP on this chip is only 125W, its just that TDP has started to lose its meaning. These days the peak power consumption is "as much as we can get into the chip without exceeding temperature limits".

enthusiast cooling tech has advanced quite a bit, too.

Looking at the reviews of the Noctua air cooler, it does better than those giant water coolers.

Air coolers can do a better job than AIOs depending on the situation, for sure. I use a Noctua air cooler on my 3900X, and it's great. But when I had the same cooler on a 2700X, it was awful, and moving to a Corsair H60 (120mm radiator with a single fan) was a huge improvement.

...because the 3900X is in a full-tower Fractal Design case and the 2700X is in a cramped 4U HTPC case by Silverstone which is rackmounted into a Gator traveling case. There's just no airflow inside the case and the AIO specific heat transfer is critical.

Well it doesn't really bother me if they have an end to end pipeline. Why shouldn't the top of the line CPU consume 250 watts? If AMD "overclocked" their existing design up to 250W and 5+ ghz it would just be another part in the product line.

If you want the absolute best perf, they you buy it. Otherwise you buy one the less expensive, lower wattage parts.

Because Zen2 chips can't be overclocked so much, and Intel *lake chips can be overclocked and Intel needs to ship virtually overclocked chips to make it competitive to Ryzen.

Overclocking has always been about eating into the design/binning margins. So sorta by definition if a CPU doesn't "overclock" its because its already overclocked.

What intel is doing here isn't "overclocking" they are just tightening their CPU margins up to the same levels that AMD has.

AKA, intel isn't overclocking their cpu anymore than AMD is. The only real difference is what the fmax of the design is, which in this case appears higher for the intel parts.

Now if you want to argue about how efficient a design is at a certain power level, that is more logical. And its a semi interesting case (aka downclock the intel slightly so that the perf on a given benchmark is identical to the AMD, then measure the power utilization).

Indeed. The CPUs aren't that much off in terms of price now, but between motherboards, cooling solutions, and power consumed, I would guess an Intel build is going to cost hundreds of dollars more than an equivalent AMD build.

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