Hacker News Reader

Comment by nadioca | Hacker News Reader

I wanna see a realistic benchmark that compares it against intel's x86 i"X" (6th, 7th, 8th gen) to decide if it can be called a laptop class processor in first place... BTW, it's interesting to see how good apple is in designing their custom Arm processors.

View on HN

> it's interesting to see how good apple is in designing their custom Arm processors.

ooh, probably because apple acquired a company called pa-semi (300m iirc) which had a bunch of cpu dudes doing power-efficient chips for quite a while...

Looking online about this company. Apple has acquired pa-semi for $278m in 2008 which translated in having the fasted arm processor by a wide margin a decade later, definitely paid out very well.

It took a lot less than a decade, they were already ahead when the A7 launched in 2013. So they took the lead in 5 years, and now have held it for another 5.

Gotta go down as one of the best acquisitions, it is clearly a foothold for Apple that allows them to release products no one else can... Custom silicon chips are the basis for nearly all of their differentiating products - FaceID / Airpods / Apple Watch

The company employed a 150-person engineering team which included people who had previously worked on processors like Itanium, Opteron and UltraSPARC.

Also principal designers of the DEC Alpha and the StrongARM, FWIW.

They hired some of the best and most experienced in the business. You get what you pay for.

They also bought Intrinsity, who designed the enhanced Cortex-A8 cores used in the Apple A4 and early Samsung Exynos SoCs.

And early Snapdragon, no?

My current laptop is a cheap Dell from 2015. It contains an unimpressive Celeron N2840 @2.16GHz but it is surprisingly usable for Web and office tasks and very low power (I never hear the fan). So I think you should also benchmark it against current Celerons (N3710).

On paper, your Celeron is specified to run at 6 W max[1], and of course has 4 cores; that's 1.5 W/core.

The AnandTech article says[2] that the new Cortex-A76 can run with a power budget of 750 mW/core, which is exactly half of the Celeron's, then.

[1] https://ark.intel.com/products/91830/Intel-Pentium-Processor...

[2] https://www.anandtech.com/show/12785/arm-cortex-a76-cpu-unve...

How does it translate in terms of performance in day to day tasks. I mean browsing, using productivity apps (etc). Do you think the extra instructions found on x86 can actually compensate the power hungry. Therefore, making x86 a more efficient architecture ?

Those 6w are a lie, the same way a core-m chips having 4.5 tdp, which in reality go as far as 17.5w.

so the TDP is a gross average measure ?

TDP today is a marketing measure. Intel's real datasheets clearly state TDP of 17.5 Watts.

turbos...

Current Celerons would be Gemini Lake (https://ark.intel.com/products/codename/83915/Gemini-Lake), if not the generation after that - after all, A76 is not exactly shipping.

https://browser.geekbench.com/processors/1967

Vs the projected 3900 Score of a76 at 3ghz.

I would expect initial benchmarks to be bad. Remember the fixes Cloudflare had to apply to ffmpeg (adding NEON-specific intrinsics to code that already had x86 ones). That's probably fairly common in most software we run (because most of us run it on x86 machines). ARM-optimized software will eventually be written.

I wonder how much can actually be optimized due the reduced number of instructions found in risc processors. Is is the case if they need some special instructions they can still fit them in an arm processor ?

Everything SIMD that relies on any flavor of SSE or AVX will need to be ported to NEON (or its variable width new thing I forgot the name). Also, many ARM SoCs have asymmetric cores - a couple i7-like ones and a couple Atom-like ones. If I see 8 cores and start 8 threads that need to sync up at the end, my process will be perceived to run at Atom speeds. At the same time, if I wake up my big powerful core to listen to me typing on a terminal, my battery will suffer - unless I have something that's "hard", I should use the small, less hungry cores.

Software will need to take individual core speed in consideration when scheduling threads if it wants to achieve best possible power consumption at a certain performance level. Today, our software assumes all cores are equal. I'm not even sure these asymmetric cores have the same SIMD widths, for instance.

Reply on news.ycombinator.com