[HN Gopher] Arm Introduces the Cortex-A715
___________________________________________________________________
Arm Introduces the Cortex-A715
Author : rbanffy
Score : 67 points
Date : 2022-06-29 16:10 UTC (6 hours ago)
(HTM) web link (fuse.wikichip.org)
(TXT) w3m dump (fuse.wikichip.org)
| e40 wrote:
| Can someone give an ARMv8.N vs ARMv9 comparison?
| als0 wrote:
| Each minor version of ARMv8 has a lot of optional extensions.
| What ARMv9 does is make some of those features mandatory. ARMv9
| also includes new optional features such as Scalable Vector
| Extensions 2 (SVE2) and Confidential Compute Architecture (CCA)
| (Intel SGX / AMD SEV equivalent).
| bpye wrote:
| Slight nit pick - but CCA is more akin to TDX than SGX.
| 2bitencryption wrote:
| could someone explain how the Arm product pipeline works?
|
| This is my (probably totally wrong) understanding:
|
| Arm makes chip specification and defines assembly language -->
| companies (Samsung, Apple) license both of these and design their
| own chips following those specs --> these designs are sent to
| fabs and produced.
|
| But what I don't get is, what "wiggle room" do companies like
| Apple and Samsung have to make their chips special? Obviously the
| M1 is a different beast from a Samsung chip, but they are both
| "Arm". So what is Apple able to do that makes the M1 the M1,
| while still also being "Armv8", the same "Armv8" as a Samsung
| chip? Does "Armv8" only mean "it must accept this instruction
| set, the rest is up to you"? Or is there requirements at the
| silicon level as well? Is this new Corex-A715 simply a
| "reference" chip for the next gen of the Arm instruction set?
| LeifCarrotson wrote:
| A lot of the customization is in the peripherals. ARM (AFAIK)
| really only specifies the processor, modern devices have lots
| of other on-board signals.
|
| The instruction set really only defines how to run mathematical
| operations on the data on its bus, what to write to registers,
| and what instructions should load and store memory to various
| pages on the memory map.
|
| Licensors add peripherals to do things that the instruction set
| doesn't define, like how to toggle an output pin from low to
| high. You use the instruction set to set a bit in a particular
| location in memory, and that turns on an LED attached to that
| pin - or they make a handy peripheral that lets you write to a
| word, because setting one bit in a 32-bit memory value is a
| read-modify-write 3-step operation and many of their devices
| have thousands of bytes of storage and RAM in an address space
| with billions of memory locations. They add I2C, SPI, CAN,
| Ethernet, USB, EEPROM, Flash, SRAM, video, etc. etc. etc. to
| make useful systems on chip - the processor is only one small
| part of that equation.
| KerrAvon wrote:
| Good explanation from 2013 here:
|
| https://www.anandtech.com/show/7112/the-arm-diaries-part-1-h...
| theresistor wrote:
| ARM produces both architecture specifications and the designs
| for chips that implement those specifications.
|
| Some companies license the architecture specification and
| design their own implementations, Apple being the leading
| example. They then pay TSMC to fabricate the chips for them.
|
| Other companies license the implementations and pay to have
| them fabricated. The latter category varies in the level of
| customization they apply to the implementations they license,
| it's generally much less customized than the what those in the
| first category achieve.
| akmittal wrote:
| >at the same performance levels as the A710, the A715 consumes
| 20% less power.
|
| I see this in every Qualcomm release. Why don't phone makers
| optimize for power efficiency?
| Narishma wrote:
| They do, but their efforts are likely thwarted by the
| continuous bloating of software.
| causi wrote:
| It's a cycle. You get cool chips, then hot chips, then cool
| chips. For example, the Snapdragon 800 was a hot chip, then
| 801, 805 chips ran cool then the 810 had terrible heat
| problems. We're in a "hot" cycle right now with 888 and 8 Gen 1
| phones typically having significant throttling problems.
| tyingq wrote:
| Because while the CPU gets more efficient, other parts go the
| other direction? Higher resolution screens, more sensors,
| radios with harder to implement requirements, and so on.
| Symmetry wrote:
| Phone makers spend a lot of time worrying about power. But
| because your screen and cell radio take up a minimum amount of
| power there's a level of diminishing returns in optimizing the
| application cores beyond a certain point.
| rbanffy wrote:
| And, besides that, when chips get smaller, even at the same
| power levels, you may end up with a smaller PCB and leave
| more space for a bigger battery.
| DowsingSpoon wrote:
| >Why don't phone makers optimize for power efficiency?
|
| They do. I don't know what misunderstandings could lead you to
| believe that phone makers don't already spend significant
| effort and resources on power efficiency.
| awill wrote:
| what OP is saying is "Why don't new phones last 20% more than
| last year's phones"
| [deleted]
| jsiaajdsdaa wrote:
| Most likely in my mind because phone makers would like you to
| purchase a new phone every 2 years, and a new battery only
| begins to degrade around that time as well.
| borissk wrote:
| Eh you seem to like conspiracy theories. Not to say there
| aren't conspiracies out there, but for some people this is
| the first and only explanation for everything. As you can see
| in the other comments there are technical reasons for what
| the phone makers are doing.
___________________________________________________________________
(page generated 2022-06-29 23:01 UTC)