What I'm not happy about is the marketing around turbo boost.

You know how ISPs used to sell "up to X Mbps"? Same idea. Your chip will turbo boost "up to 6.00 GHz".

It's basically automated overclocking, and as you learned, sometimes it can't even do it in a stable fashion. Some of those chips will never clock "up to 6.00 GHz" but they didn't lie. "up to"

It's particularly bad when they stop telling you what clock speeds are achievable with more than one core active. At best these days you get a "base clock" spec that's very slow that doesn't correspond to any operating mode that occurs in real life. You used to get a table of x GHz for y active cores, but then the core counts got too large and the limits got fuzzier.

And laptops have another layer of bullshit, because the theoretical boost clocks the chip is capable of will in practice be limited by the power delivery and cooling provided by that specific machine, and the OEMs never tell you what those limits are. So they'll happily take an extra $200 for another 100MHz that you'll never see for more than a few milliseconds while a different model with a slower-on-paper CPU with better cooling can easily be more than 20% faster.

Yes, this is the situation for my dell laptop's i7-1165G7. Alleged turbo boost to 4.7ghz! In reality, it will hit that for a sec and then throttle to ~1ghz. I had to disable the turbo boost AND two cores in bios to let it even achieve ~2.0ghz speeds consistently. It's a total scam. Turns out my 8th-Gen i5 laptop is almost the same speed on benchmarks, just because it's a few mm thicker with better cooling.

Do you think that happened because you had insufficient cooling?

Its hard to cool these new chips. AMD included.

Even if GP's cooling setup was less than ideal, the chip should have throttled itself to a stable frequency instead of crashing left and right.

It might not have throttled fast enough. Without sufficient thermal mass (or with insufficient heat transfer to that thermal mass, for instance if the thermal paste is misapplied), it might heat up too fast for the sensors to keep up.

For different reasons though. AMD's chiplets produce heat in a small area which makes it hard to transfer heat quickly. Intel just use a shitload more power and thus more heat.

That’s not entirely it though. Modern AMD and Intel chips are built to run at their thermal/frequency limits and will jump to those limits at a moments notice in order to maximize performance.

So unless you have powerful cooling you will hit the thermal limit.

I didnt say that it was everything that matters, just commenting on the difference between them.

    enable settings that capped max watts and temperature for throttling to 90c.

You were going above 90C before???

My first thought is that seems insane, but is apparently normal for that chip, according to Intel: "your processor supports up to 100°C and any temperatures below it are normal and expected"

https://community.intel.com/t5/Processors/i9-14900K-temperat...

That is just wild though. On one hand you should obviously get the performance that was advertised and that you paid for. On the other hand IMO operating a CPU at 90-100C is just insane. It really feels like utter desperation on Intel's part.

I would be curious what kind of cooling setup you have.

the amount of cooling you get is proportional to the difference of component temperature to ambient temperature. thats why modern chips are engineered to run much hotter.

Until Dust Puppy kills 'em

Hey, is there a cooling solution that sprays water on some sort of heat spreader and lets it evaporate? Kidding. Kinda. But actually, is that possible?

Heat pipes sort of do that naturally without any active "spraying". They contain a fluid that phase changes and carries heat away. Closed loop water coolers have the active flow of water you want for maximum effect. I don't think your idea would be an improvement on that.

That's essentially what vapor chamber coolers are. It's a sealed unit where the working fluid evaporates on the CPU end, absorbing a ton of heat, and then condenses on the other side, before going back to do the cycle again. Because the heat of vaporization is so large, these can move a lot more heat than ordinary heat sinks.

For both Intel/AMD 100C is now a target, not a limit.

And for the consumer, changing the computer every 2 years, because the processor died, is a limit, not a target. /s

> On the other hand IMO operating a CPU at 90-100C is just insane.

No it isn't, the manufacturer literally says it's normal! I think people who spend as much money on cooling setups as the chip are the insane ones.

My favorite story: I once put Linux on a big machine that had been running windows, and discovered dmesg was full of thermal throttling alerts. Turns out, the heatsink was not in contact with the CPU die because it had a nub that needed to occupy the same space as a little capacitor.

I'd been using that machine to play X-plane for over two years, and I never noticed. It was not meaningfully slower: the throttling events would only happen every ten or so seconds. I'm still using it today, although with the heatsink fixed :)

I have a garage machine with a ca. 2014 Haswell that's been running full tilt at 90C+ for a good bit of its life. It just won't die.

     I have a garage machine with a ca. 2014 Haswell 
     that's been running full tilt at 90C+ for a good 
     bit of its life. It just won't die.

First of all: that's awesome.

Second: what's it doing spending that much time "full-tilt?" Just curious. Sounds like something interesting.

Alas, nothing that interesting. It mined bitcoin for awhile, back when it was feasible to make practically useful quantities of it that way. Never profitably obviously.

Right now, I use it as a 200W space heater I can turn off and on via SSH, just running busyloops. It works well enough for a single car garage in California.

Temperatures like that have been fairly normal for a few generations now - both for Intel and AMD. It might look insane compared to what you were used to seeing a decade ago, but it's actually not that crazy.

First, the temperature sensors got a lot better. Previously you only had one sensor per core/cpu, and it was placed wherever there was space - nowadays it'll have dozens of sensors placed in the most likely hotspots. A decade ago a 70C temp meant that some parts of the CPU were closer to 90C, whereas nowadays a 90C temp means the hottest part is actually 90C.

Second, the better sensors allow more accurate tuning. While 100C might be totally fine, 120C is probably already going to cause serious damage. The problem here is that you can't just rely on a somewhat-distant sensor to always be a constant 20C below the peak value: it's also going to be lagging a bit. It might take a tenth of a second for that temp spike in the hotspot to reach the sensor, but in the time between the spike starting and the temp at the sensor raising enough to trigger a downthrottle you could've already caused serious damage. A decade ago that meant leaving some margin for safety, but these days they can just keep going right up to the limit.

It's also why overclocking simply isn't really a "thing" anymore. Previous CPUs had plenty of safety margin left for risk-takers to exploit, modern CPUs use up all that margin by automatically overclocking until it hits either a temperature limit or a power draw limit.

Exactly. Temperature measurements are a lot like available memory measurements in that regard. People wonder why the OS uses up all available memory, and it's because the OS knows that empty memory is useless, while memory used to cache disk is potentially useful (and can always be discarded when that memory is needed for something else). So, the persistent state of memory is always "full".

Similarly, processors convert thermal headroom to performance, until they run out of thermal headroom. So if you improve the cooling on a processor that has work to do (rather than sleeping), it will use up that cooling and perform better, rather than performing the same and running cooler.

(Mobile processors operate differently, since they need to maintain a much tighter thermal envelope to not burn the user. And processors can also target power levels rather than thermals. But when a processor is in its default "run as fast as possible" mode, its normal operating temperature will be close to the 100C limit.)

There's a side benefit to this as well, your cooling solution is more effective at 90C than it is at 40C, you know, highschool physics, deltaT and all that.

That also comes with the side effect that the transistors are leakier at high temperature, leading to higher power for the same performance as compared with operating at a lower temperature. This effect is significant: in mobile systems it can easily be the case that turning on a fan (or speeding it up) leads to a net decrease in power consumption because the power saved by making the chip less leaky is more than the power spent running the fan.

> People wonder why the OS uses up all available memory

This is really no excuse to have Windows eating 12GB of RAM with an Edge (with 2 static tabs), excel some antivirus and Teams running. This (12GB) is just sick.

The good news is: you do not understand how modern (last 30+ years) OS memory management works.

If you have free ram the OS will cache all the recently accessed things. It costs effectively zero to cache them when you access them, and it costs effectively zero to evict from the cache if you actually need the memory for "useful" work. And if the cached thing is useful in the mean time, you win because RAM is still orders of magnitude faster than SSD. None of the scenarios are a perf loss. The only scenarios are "win" or "no gain."

"But won't the next application I load, load faster if there is free RAM?"

If you are asking this question, please refer back to the previous concept -- "it costs effectively zero to evict from the cache if you actually need the memory for 'useful' work." This is where people typically get confused. They think it takes work to evict things from the cache, just like it would require work to remove frequently used objects from your physical desk if you needed to free up space.

Once you understand that the rest should fall into place.

> but it's actually not that crazy.

Unless you take reliability into account.

    It might look insane compared to what you were used 
    to seeing a decade ago, but it's actually not that crazy.

I'm comparing it to a mid-range system I built last year: an Intel i5-13400F with a $60 closed-loop cooler.

It doesn't go past 45C even during Prime95 runs using all cores. And the 120mm fans aren't exactly howling either.

    First, the temperature sensors got a lot better. Previously 
    you only had one sensor per core/cpu, and it was placed wherever 
    there was space - nowadays it'll have dozens of sensors placed 
    in the most likely hotspots.

That's awesome to know. Thanks for the explanation.

Seems scary that 10% difference in clock frequency is makes/breaks stability.

How much margin is really there?

Dynamic switching power (i.e. the fraction of the chip's power consumption from actually switching transistors, as opposed to just "being on") scales with V^2 * f, where V=voltage and f=frequency, and V in turn depends on f, where higher frequencies need higher voltage. Not really linearly (It's Complicated(tm)), but it's not a terrible first-order approximation, which makes the dynamic switching power have a roughly cubic dependency on frequency.

Therefore, 1.1x the frequency at the high end (where switching power dominates) is 1.33x the power draw.

Those final few hundred MHz really hurt. Conversely, that's also why you see "Eco" power profiles with a major reduction in power draw that cost you maybe 5-10% of your peak performance.

Did you try cleaning everything and re-mounting the cooler with new paste? I’ve seen similar behavior when people mess up and get bubbles in their paste. Do you see wildly different temperature readouts for different cores?

I also recently built a system with the 14900KF on an ASUS TUF motherboard and NZXT Kraken 360 cooler, and so far I haven't experienced any issues running everything at default BIOS settings (defaulted to 5.7GHz). I haven't seen temps above 70C yet, although granted I also haven't seen CPU load go above 40%, and haven't tried running any benchmarking software.

I'm curious about what you are using for cooling, as 90C at 5.4ghz seems way off compared to what I am seeing on my processor, but it could just be that I'm not pushing my processor quite as hard even with the higher clock rate.