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Questions and Answers : Unix/Linux : ARM application
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fzs600

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Message 64283 - Posted: 8 Aug 2021, 8:54:09 UTC

Hello
can you develop an ARM application?
Is it possible?
thanks
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Les Bayliss
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Message 64284 - Posted: 8 Aug 2021, 9:28:48 UTC - in response to Message 64283.  

No. Climate models are too complex for that.

Also, the models currently used are those created and used by the UK Met Office.
Oxford Uni doesn't create their own.
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Profile Dave Jackson
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Message 64287 - Posted: 8 Aug 2021, 11:00:25 UTC

Hello
can you develop an ARM application?
Is it possible?
thanks

It is possible that the OpenIFS tasks might be able to run on risc chips. If not then new Macs will be in trouble.
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KAMasud

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Message 64288 - Posted: 8 Aug 2021, 12:05:27 UTC

Interesting though. My ARM device is running some flavour of Linux. Linux is Linux, what does the architecture of the CPU have to do with the matter?
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Message 64289 - Posted: 8 Aug 2021, 13:18:33 UTC - in response to Message 64288.  

The program uses one of the SSE instruction sets.
I forget now whether it's SSE2 or SSE4.
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wateroakley

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Message 64297 - Posted: 9 Aug 2021, 9:23:02 UTC - in response to Message 64288.  

Interesting though. My ARM device is running some flavour of Linux. Linux is Linux, what does the architecture of the CPU have to do with the matter?
There are far too many design, implementation, programming and compiling variables to assume that the CPU architecture won't matter. The programs we are running were aimed at super-computers. Support for ARMv8-A in Linux is from around 2012. It's a long while since I used the first generation 6502 assembler. The original ARM was hard-wired, no Microcode (the Hardware Abstraction Layer) that translates the executable program into the chip's reduced instruction set. Even it ran an executable in Linux, these RISC chips are aimed at low power devices and will have (IIRC) an external L3 cache typically from 256KB to 4MB. Without architecture targeted programming/compilation, plus deep cache, don't expect data and cpu intensive programs (like CPDN) to behave nicely on a RISC device.
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KAMasud

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Message 64298 - Posted: 9 Aug 2021, 9:52:07 UTC - in response to Message 64283.  

Hello
can you develop an ARM application?
Is it possible?
thanks

__________________
@fzs600. Go to World Community Grid. They need as many ARM devices( mobile devices, mobile phones, Single Board Computers) as possible for their COVID19 project. No lack of work either. Best of luck.
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Message 64300 - Posted: 9 Aug 2021, 10:44:01 UTC - in response to Message 64297.  

Interesting though. My ARM device is running some flavour of Linux. Linux is Linux, what does the architecture of the CPU have to do with the matter?
There are far too many design, implementation, programming and compiling variables to assume that the CPU architecture won't matter. The programs we are running were aimed at super-computers. Support for ARMv8-A in Linux is from around 2012. It's a long while since I used the first generation 6502 assembler. The original ARM was hard-wired, no Microcode (the Hardware Abstraction Layer) that translates the executable program into the chip's reduced instruction set. Even it ran an executable in Linux, these RISC chips are aimed at low power devices and will have (IIRC) an external L3 cache typically from 256KB to 4MB. Without architecture targeted programming/compilation, plus deep cache, don't expect data and cpu intensive programs (like CPDN) to behave nicely on a RISC device.

______________________________________________
The cache problem I can understand, only now they have started to increase the cache size but still nowhere near the required amount.
Les, the instruction sets SSE2 and SSE4 are in Linux. The others also, that is why we are running WU's in Linux on x86 and x64.
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Message 64303 - Posted: 9 Aug 2021, 13:06:33 UTC - in response to Message 64289.  

The program uses one of the SSE instruction sets.
I forget now whether it's SSE2 or SSE4.


I remember when this came in and older CPU's that didn't support SSE2 became obsolete as far as CPDN is concerned. Not sure whether SSE4 is a requirement now or not. Linux or other OS having SSE2/4 may be needed but the CPU needs to support the instruction set as well.
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wateroakley

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Message 64306 - Posted: 9 Aug 2021, 19:20:55 UTC - in response to Message 64303.  

The program uses one of the SSE instruction sets.
I forget now whether it's SSE2 or SSE4.


I remember when this came in and older CPU's that didn't support SSE2 became obsolete as far as CPDN is concerned. Not sure whether SSE4 is a requirement now or not. Linux or other OS having SSE2/4 may be needed but the CPU needs to support the instruction set as well.


SSE2 was first supported around 2000 on Pentium devices as part of INTEL proprietary IA-32 architecture, a step beyond the late-1990's INTEL MMX instruction set. AMD provided an emulation of IA-32 instructions on Athlon devices. SSE2 was (IIRC) was the limit to use INTEL P4 and AMD Athlon devices for early CPDN contributors. IIRC the SSE2 instruction set (or emulation by the Hardware Abstraction Layer) of the target CPU is essential for CPDN.
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Message 64307 - Posted: 9 Aug 2021, 20:33:13 UTC
Last modified: 9 Aug 2021, 20:41:33 UTC

With original cpdn and the initial boinc cpdn, not even SSE was needed as a Pentium II could run it. I can't remember when it happened but then the base became SSE sometime between 2004 and 2006. And then in 2009, new executables were compiled that required SSE2. I don't believe that any further CPU requirements exist for the wah2 or hadam type models beyond SSE2 and intel/amd x86/x86_64 type CPUs.
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Questions and Answers : Unix/Linux : ARM application

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