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This is an entirely uncontroversial take among experts in the space. x86 is an old CISC-y hot mess. RISC-V is a new-school hyper-academic hot mess. Recent ARM is actually pretty good. And none of it matters, because the uncore and the fabrication details (in particular, whether things have been tuned to run full speed demon or full power sipper) completely dominate the ISA. In the past x86 didn't dominate in low powe…
VIA used to make low power x86 processors
This is an entirely uncontroversial take among experts in the space. x86 is an old CISC-y hot mess. RISC-V is a new-school hyper-academic hot mess. Recent ARM is actually pretty good. And none of it matters, because the uncore and the fabrication details (in particular, whether things have been tuned to run full speed demon or full power sipper) completely dominate the ISA. In the past x86 didn't dominate in low powe…
> x86 didn't dominate in low power because Intel had the resources to care but never did Remember Atom tablets (and how they sucked)?
(Also probably due to it is a tablet, so it have a reasonable fast storage instead of hdds like notebooks in that era)
Ok. When will we get the laptop with AMD CPU that is on par with a Macbook regarding battery life?
How much of the Mac's impressive battery life is due purely to CPU efficiency, and how much is due to great vertical integration and the OS being tuned for power efficiency? It's a genuine question; I'm sure both factors make a difference but I don't know their relative importance.
And yet... the world keeps proving Intel and AMD wrong on this premise with highly efficient Arm parts. While sure, there's bound to be improvements to make on x86 ultimately its a variable length opcode encoding with a complex decoder path. If nothing else, this is likely a significant issue in comparison to the nicely word aligned op code encoding arm has and surely given apples to apples core designs, the opcode d…
> its a variable length opcode encoding with a complex decoder path In practice, the performance impact of variable length encoding is largely kept in check using predictors. The extra complexity in terms of transistors is comparatively small in a large, high-performance design. Related reading: https://patents.google.com/patent/US6041405A/en https://web.archive.org/web/20210709071934/https://www.anand...
>So fixed-length instructions seem really nice when you're building little baby computers, but if you're building a really big computer, to predict or to figure out where all the instructions are, it isn't dominating the die. So it doesn't matter that much.
Well, efficiency advantages are the domain of little baby computers. Better predictors give you deeper pipelines without stalls which give you higher clock speeds - higher wattages
Ok. When will we get the laptop with AMD CPU that is on par with a Macbook regarding battery life?
Steamdeck with Windows 11 and SteamOS is a whole different experience. When running SteamOS and doing web surfing, the fan don't even really spin at all. But when running windows 11 and do the exact same thing, it just spins all the time and becomes kinda hot.
I used laptops with both Intel and AMD CPUs, and I read/watch a lot of reviews in thin and light laptop space. Although AMD became more power efficient compared to Intel in the last few years, AMD alternative is only marginally more efficient (like 5-10%). And AMD is using TSMC fabs.
On the other hand Qualcomm's recent Snapdragon X series CPUs are significantly more efficient then both Intel and AMD in most tests while providing the same performance or sometimes even better performance.
Some people mention the efficiency gains on Intel Lunar Lake as evidence that x86 is just as efficient, but Lunar Lake was still slightly behind in battery life and performance, while using a newer TSMC process node compared to Snapdragon X series.
So, even though I see theoretical articles like this, the empirical evidence says otherwise. Qualcomm will release their second generation Snapdragon X series CPUs this month. My guess is that the performance/efficiency gap with Intel and AMD will get even bigger.
From what I have heard it's not the RISCy ISA per se, it's largely arm's weaker memory model. I'd be happy to be corrected, but the empirical core counts seem to agree.
Earlier quoted context omitted.
PPA results comparing x86 to ARM say otherwise; take a look at Ryzen's embedded series and Intel's latest embedded cores.
Have they reached apple m level of performance/watt after half a decade of the apple m parts being out yet? Do either AMD or Intel beat Apple in any metric in mobile?
You’ll pry the ARM M series chips of my Mac from my cold dead hands. They’re a game changer in the space and one of the best reasons to use a Mac. I am not a chip expert it’s just so night and day different using a Mac with an arm chip compared to an Intel one from thermals to performance and battery life and everything in between. Intel isn’t even in the same ballpark imo. But competition is good and let’s hope they…
That's not mostly because of a better ISA. If Intel and Apple had a chummier relationship you could imagine Apple licensing the Intel x86 ISA and the M series chips would be just as good but running x86. However I suspect no matter how chummy that relationship was, business is business and it is highly unlikely that Intel would give Apple such a license.
Genuinely asking -- what is it due to? Because like the person you're replying to, the m* processors are simply better: desktop-class perf on battery that hangs with chips with 250 watt TDP. I have to assume that amd and intel would like similar chips, so why don't they have them if not due to the instruction set? And AMD is using TSMC, so that can't be the difference.