12 ms·

I have so many questions: - Where can I get the ISA specification?[1] - Where can I get a compiler? - Is there a link to the "softcore model"? With RISC-V y

by bem94 7y ago

I have so many questions: - Where can I get the ISA specification?[1] - Where can I get a compiler? - Is there a link to the "softcore model"? With RISC-V you can start very simple and small (micro-controller) and work your way up in understanding and implementation to a very large core (application class). POWER is a monster of an architecture, designed more for "big iron". I guess that might limit the "hobbyist" factor RISC-V has. 1. This I think, all 1200 pages of it: https://openpowerfoundation.org/?resource_lib=power-isa-version-3-0 https://openpowerfoundation.org/?resource_lib=power-isa-vers...

benchaney 7y ago
In response to your second question, I believe that gcc and llvm both support power.
kop316 7y ago
I own a Talos II (https://www.raptorcs.com/TALOSII/ https://www.raptorcs.com/TALOSII/) computer. It actually runs an official port of Debian (https://wiki.debian.org/PPC64 https://wiki.debian.org/PPC64) on it, which includes a compiler.
- mshook 7y ago
  If I may ask why did you get it, which reasons? I like the cool non x86 factor but it's quite expensive... EDIT: Forgot to mention the open argument which is quite amazing as well (I've followed what Talos does).
  - kop316 7y ago
    I tend to buy server level hardware for my own usage. It tends to last a LOT longer. With that in mind, it was roughly comparable to what I would have paid for a comparable Intel Xeon, and I like the fact that I know all of the code that runs on it (the only code that I can't actually change is the OTP memory that it first executes when it boots up, and even then you can inspect it!).
    - Avamander 7y ago
      Thanks for supporting the development of open hardware and software. Very few of us can afford to do so.
      - kop316 7y ago
        They actually came out with a Blackbird, and I have been considering getting one of them to replace my server (it runs FreeNAS, but I have gotten my Debian system to run an encrypted ZFS drive).
  - dragontamer 7y ago
    The 18-core has decent performance. If it weren't for AMD EPYC Rome chips coming out a month ago, I would have considered a Talos II. 18-cores with 4x SMT == 72 threads per Power9. That's a lot of threads, no matter how you look at it.
    - slovenlyrobot 7y ago
      That's a whole lot of SMT. Can anyone comment on how it behaves compared to hyperthreading? I'm assuming at 4x each core must have a ton more execution units to go around
      - dragontamer 7y ago
        Power9 is basically "Bulldozer done right". Each SMT4 Power9 core is incredibly fat, with 4x load/store units 4x ALUs, 2x Vector units. Bulldozer probably would have called each SMT4 core a collection of 4-cores. But only 1x divider, 1x crypto unit per SMT4 core. The chief downside to Power9 is that it only supports 128-bit vectors, and these 128-bit vectors are executed by ganging-together the ALU units. (so 4x 64-bit ALUs == 2x 128-bit vectors processed per clock tick). Compared to AMD Zen (4x 128-bit pipelines), AMD Zen 2 (4x 256-bit pipelines), and Intel Skylake-X (3x 512-bit pipelines), Power9's SIMD capabilities are tiny. Another oddity: most instructions take 2-clock ticks to execute, even simple instructions like XOR or Add. This increased latency is likely the reason why it performs so poorly with Python / PHP code. But when code is written for Power9, it works quite well. Stockfish chess seems to work extremely well on Power9, likely because Stockfish scales to many "cores" well (fully taking advantage of SMT4), and only has 64-bit operations. One more wildcard: Power9 has 10MB (!!!) L3 cache for every 2-cores. That's 90MB L3 cache on the 18-core. I presume that real-life database applications would benefit greatly from this oversized L3 cache. EDIT: It should be noted that the L3 caches serve as victim-caches of other L3 caches. So Power9 core-pair 01 can have its 10MB L3 cache serve as a "L3.1 cache" of core-pair 23. AMD Zen / Zen2 L3 cache CANNOT use this functionality. So AMD Zen2 64-core may have 128MB of L3 cache, but each core only "really" can go up to 16MB of L3 cache (because the other 112MB of L3 cache is only for other cores/module) EDIT: Also note, Power9 came out a few years ago at 14nm, while Zen2 came out on the 7nm node a month ago. I think a new 7nm Power9 update is planned, but I don't know what its timeframe is. In effect, you could have 1-program using the entire 90MB L3 cache for itself on Power9. While AMD Zen2 requires (at minimum) 8-programs, each program using only 16MB L3. This design decision is clear in the intended use of the chips: Zen2 is clearly targeted at the cloud-market, while Power9 is big-iron / databases. -------- Unfortunately, most of the benchmarks these days show that AMD EPYC / Rome is just the better overall processor. Still, 18-core Power9 is relatively cheap: a complete 18-core / 72-thread system for $4000ish: https://secure.raptorcs.com/content/TLSDS3/purchase.html https://secure.raptorcs.com/content/TLSDS3/purchase.html Cheap for Power9 anyway. AMD EPYC is also relatively cheap. You can get a 16-core / 32-thread / 32MB L3 cache AMD Ryzen 9 3950x for only $700 these days (and maybe a complete system build for only $2500).
- voldacar 7y ago
  I have drooled over the Talos II for quite some time... Do you have a particular use case that makes POWER make sense over x86, or do you share my paranoia and love of non-mainstream ISAs?
  - kop316 7y ago
    I share and respect your paranoia. I have a love of inspecting code and not having backdoors in my processor.
    - voldacar 7y ago
      For sure. It's nice that open source firmware replacements have been making progress, especially since the Intel ME fiasco, but it never ceases to amaze me that right now you can go out and get a modern, ultra high performance workstation with every single chip running auditable firmware. Hopefully we will start seeing more affordable POWER systems now that it is a fully open architecture
      - acqq 7y ago
        > with every single chip running auditable firmware But disks? Isn’t their firmware closed?
        voldacar 7y ago
        Ugh I guess there always has to be an exception. Maybe you could run everything in a ramdisk? It supports up to 2TB of ram after all
        justinclift 7y ago
        Maybe OpenSSD would be functional enough to use: http://openssd.io http://openssd.io http://www.openssd-project.org/wiki/The_OpenSSD_Project http://www.openssd-project.org/wiki/The_OpenSSD_Project
        tpearson-raptor 7y ago
        What you can do with a trusted CPU domain is use FDE. FDE is standard practice for anyone even remotely concerned about security in the first place. So the firmware that matters -- the firmware that can subvert the system due to privilege level, etc. -- is open. No other vendor aside from some lower end ARM toy SoCs can say that.
- cipherboy 7y ago
  Fedora [0], Red Hat [1], Ubuntu [2], and SUSE [3] all have their own ppc64le ports as well so there are lots of choices out there if anyone is interested. Even Gentoo has one [4][5]! [0]: https://alt.fedoraproject.org/alt/ https://alt.fedoraproject.org/alt/ [1]: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html-single/8.0_release_notes/index#architectures https://access.redhat.com/documentation/en-us/red_hat_enterp... [2]: https://ubuntu.com/download/server/power https://ubuntu.com/download/server/power [3]: https://www.suse.com/products/power/ https://www.suse.com/products/power/ [4]: https://wiki.gentoo.org/wiki/Handbook:PPC64 https://wiki.gentoo.org/wiki/Handbook:PPC64 [5]: https://www.gentoo.org/downloads/ https://www.gentoo.org/downloads/
  - classichasclass 7y ago
    Fedora 30 on this Talos II. Works well.
  - _emacsomancer_ 7y ago
    Void Linux as well: https://www.talospace.com/2019/01/void-linux-goes-power9.html https://www.talospace.com/2019/01/void-linux-goes-power9.htm... Although it's not official at this point I don't think.
    - classichasclass 7y ago
      No, though my impression is it's progressing pretty well, so I think it will get there.
- martin1975 7y ago
  can you run AIX on it?
  - CrystalGamma 7y ago
    No. AFAIK AIX only runs on PowerVM systems, which none of the OpenPOWER systems are.
    - Annatar 7y ago
      Then what's the point if I can't run AIX on it?!?
- Annatar 7y ago
  "Talos™ II 2U Rack Mount Server TL2SV1 Talos™ II 2U Rack Mount Server Starting at $6,089.00" Not at $6,089.00; they can forget that. It has to cost no more than $500 USD or this will be a repeat of the same mistake Sun Microsystems did. Will these companies ever learn? One cannot charge enterprise prices if one wants to build an upward spiral. Intel systems dominate because they are dirt cheap and convenient to buy.
  - fluffything 7y ago
    You can't find a modern Intel Xeon Gold CPU for less than 2000$. If you buy 2, and a motherboard, you are already in the 6000$ ballpark, and then you still need to buy everything else (PSU, RAM, SSDs, GPGPU, etc.).
    - Annatar 7y ago
      I can build (and have) a fully decked-out intel-based 1U server for $1,800 USD, so this Talos thing can't compete: it's not cost-effective no matter how one slices and dices it. This company is repeating the same mistake IBM, hp, SGI and Sun before it made. Those who do not learn from history are doomed to repeat mistakes of those who came before them. Have you bought one of those Talos systems?
      - fluffything 7y ago
        I'll believe you if you are able to provide a link to two Xeon Gold CPUs costing the same or less than the 1800$ you claim you are able to build a full 1U rack with two of them.
- jammygit 7y ago
  Have you had any issues with it, or has it required any additional configuration? I'm extremely curious about the real world use of Power chips
blattimwind 7y ago
PowerPC and POWER are relatively mainstream. It's supported by IBM XL, GCC, Clang and most major JITs (including luajit).
- floatboth 7y ago
  > including luajit Well, a fork of luajit. LuaJIT proper has been abandoned for months…
  - ksec 7y ago
    I thought somebody picked up as new maintainer and then Mike Pall was back. What happened? He lost interest?
    - jpfr 7y ago
      No new commits since January. https://github.com/LuaJIT/LuaJIT https://github.com/LuaJIT/LuaJIT
- squarefoot 7y ago
  Exactly. I can't speak for big iron and server usage because last time I used a POWER based server at work it was still AIX restricted (though IBM was already aiming at Linux for the future), however on PPC about everything user level was available 15 years ago, including USB devices support and compilers. When the very first PPC Mac Mini came out I purchased one to be used as a living room media PC connected to a projector and running a customized Debian which would load a media player (Freevo) just after boot. Worked like charm for years, no complains at all save for the atrocious loud "boonnnngggg" sound at power up that I was never able to turn off:^)
shawnz 7y ago
> POWER is a monster of an architecture, designed more for "big iron". It's the same architecture as PowerPC, designed for desktops, isn't it? Have things really changed so much since then?
- yellowapple 7y ago
  I wouldn't be surprised if they have, given that PowerPC desktops haven't been mainstream for more than a decade now, and in the meantime IBM's servers have been marching on.
  - close04 7y ago
    The last truly mainstream PowerPC desktop was Apple's 2005 Quad-G5 PowerMac. There were other PowerPC machines after this, the PS3 being the most notable. But they were either not desktops or not mainstream. I'm a hardware nostalgic and have both gathering dust in my basement. So I can't wait for a PowerPC revival of any kind.
    - floatboth 7y ago
      Raptor Talos/Blackbird is a niche, expensive revival, but a revival nonetheless :)
      - close04 7y ago
        I may have been overly generous with the "of any kind" :). That's a bit on the expensive side and the ecosystem and platform flexibility in terms of upgrade are still pretty slim/locked in. Something that's open and cheap enough to spark general interest would be much more interesting.
        yellowapple 7y ago
        The Blackbirds don't look too expensive, and Talos' hardware in general is about as open as it gets (putting even the x86 market to shame, let alone the PowerPC Apple desktops).
circuit 7y ago
- Where can I get a compiler? PGI has a free POWER compiler https://www.pgroup.com/products/community.htm https://www.pgroup.com/products/community.htm
- zie 7y ago
  LLVM and GCC both support POWER.
floatboth 7y ago
> all 1200 pages of it Sounds weak, one of the versions of ARMv8 has a spec that's exactly 6666 (!) pages. I would expect IBM to be more detailed lol
- mhh__ 7y ago
  Spec or manual? The ARM Spec I've seen is also 1200ish pages whereas the programmers manual is indeed thousands of pages
  - floatboth 7y ago
    Ah, they indeed have a shorter spec, but it's at 2611 pages now https://static.docs.arm.com/ddi0596/d/ISA_A64_xml_v85A-2019-06_OPT.pdf https://static.docs.arm.com/ddi0596/d/ISA_A64_xml_v85A-2019-... It's actually a document generated from machine-readable XML files https://alastairreid.github.io/ARM-v8a-xml-release/ https://alastairreid.github.io/ARM-v8a-xml-release/
- CrystalGamma 7y ago
  IBM doesn't do wacky stuff like Pointer authentication that creeps into every corner of the spec, making everything more complicated …
ajross 7y ago
> POWER is a monster of an architecture FWIW: the original RS/6000 devices were 20-40 MHz in-order CPUs with architectures objectively simpler than a RISC-V microcontroller like the E310.
ksec 7y ago
And more questions, Correct me if I am wrong, So this is opening up of POWER ISA, since there is quite a few different version or Revision of that, I assume that is the one beings used in POWER9 and in the future POWER10? And it is more like RISC-V ISA open source rather than MIPS open source ?( I believe POWER was previously opened but with Cooperate Protection speak all over it ). And this does not include Implementations, like POWER9? I mean, if all of these were true, without implementation , or at leats licensing it for cheap, it still doesn't change the market one bit.
ajdlinux 7y ago
The toy soft-core VHDL model that is referred to there will be available at https://github.com/antonblanchard/microwatt https://github.com/antonblanchard/microwatt at some point in the next couple of days.

by bem94 7y ago

benchaney 7y ago

In response to your second question, I believe that gcc and llvm both support power.

kop316 7y ago

I own a Talos II (https://www.raptorcs.com/TALOSII/ https://www.raptorcs.com/TALOSII/) computer. It actually runs an official port of Debian (https://wiki.debian.org/PPC64 https://wiki.debian.org/PPC64) on it, which includes a compiler.

mshook 7y ago
If I may ask why did you get it, which reasons? I like the cool non x86 factor but it's quite expensive... EDIT: Forgot to mention the open argument which is quite amazing as well (I've followed what Talos does).
- kop316 7y ago
  I tend to buy server level hardware for my own usage. It tends to last a LOT longer. With that in mind, it was roughly comparable to what I would have paid for a comparable Intel Xeon, and I like the fact that I know all of the code that runs on it (the only code that I can't actually change is the OTP memory that it first executes when it boots up, and even then you can inspect it!).
  - Avamander 7y ago
    Thanks for supporting the development of open hardware and software. Very few of us can afford to do so.
    - kop316 7y ago
      They actually came out with a Blackbird, and I have been considering getting one of them to replace my server (it runs FreeNAS, but I have gotten my Debian system to run an encrypted ZFS drive).
- dragontamer 7y ago
  The 18-core has decent performance. If it weren't for AMD EPYC Rome chips coming out a month ago, I would have considered a Talos II. 18-cores with 4x SMT == 72 threads per Power9. That's a lot of threads, no matter how you look at it.
  - slovenlyrobot 7y ago
    That's a whole lot of SMT. Can anyone comment on how it behaves compared to hyperthreading? I'm assuming at 4x each core must have a ton more execution units to go around
    - dragontamer 7y ago
      Power9 is basically "Bulldozer done right". Each SMT4 Power9 core is incredibly fat, with 4x load/store units 4x ALUs, 2x Vector units. Bulldozer probably would have called each SMT4 core a collection of 4-cores. But only 1x divider, 1x crypto unit per SMT4 core. The chief downside to Power9 is that it only supports 128-bit vectors, and these 128-bit vectors are executed by ganging-together the ALU units. (so 4x 64-bit ALUs == 2x 128-bit vectors processed per clock tick). Compared to AMD Zen (4x 128-bit pipelines), AMD Zen 2 (4x 256-bit pipelines), and Intel Skylake-X (3x 512-bit pipelines), Power9's SIMD capabilities are tiny. Another oddity: most instructions take 2-clock ticks to execute, even simple instructions like XOR or Add. This increased latency is likely the reason why it performs so poorly with Python / PHP code. But when code is written for Power9, it works quite well. Stockfish chess seems to work extremely well on Power9, likely because Stockfish scales to many "cores" well (fully taking advantage of SMT4), and only has 64-bit operations. One more wildcard: Power9 has 10MB (!!!) L3 cache for every 2-cores. That's 90MB L3 cache on the 18-core. I presume that real-life database applications would benefit greatly from this oversized L3 cache. EDIT: It should be noted that the L3 caches serve as victim-caches of other L3 caches. So Power9 core-pair 01 can have its 10MB L3 cache serve as a "L3.1 cache" of core-pair 23. AMD Zen / Zen2 L3 cache CANNOT use this functionality. So AMD Zen2 64-core may have 128MB of L3 cache, but each core only "really" can go up to 16MB of L3 cache (because the other 112MB of L3 cache is only for other cores/module) EDIT: Also note, Power9 came out a few years ago at 14nm, while Zen2 came out on the 7nm node a month ago. I think a new 7nm Power9 update is planned, but I don't know what its timeframe is. In effect, you could have 1-program using the entire 90MB L3 cache for itself on Power9. While AMD Zen2 requires (at minimum) 8-programs, each program using only 16MB L3. This design decision is clear in the intended use of the chips: Zen2 is clearly targeted at the cloud-market, while Power9 is big-iron / databases. -------- Unfortunately, most of the benchmarks these days show that AMD EPYC / Rome is just the better overall processor. Still, 18-core Power9 is relatively cheap: a complete 18-core / 72-thread system for $4000ish: https://secure.raptorcs.com/content/TLSDS3/purchase.html https://secure.raptorcs.com/content/TLSDS3/purchase.html Cheap for Power9 anyway. AMD EPYC is also relatively cheap. You can get a 16-core / 32-thread / 32MB L3 cache AMD Ryzen 9 3950x for only $700 these days (and maybe a complete system build for only $2500).
voldacar 7y ago
I have drooled over the Talos II for quite some time... Do you have a particular use case that makes POWER make sense over x86, or do you share my paranoia and love of non-mainstream ISAs?
- kop316 7y ago
  I share and respect your paranoia. I have a love of inspecting code and not having backdoors in my processor.
  - voldacar 7y ago
    For sure. It's nice that open source firmware replacements have been making progress, especially since the Intel ME fiasco, but it never ceases to amaze me that right now you can go out and get a modern, ultra high performance workstation with every single chip running auditable firmware. Hopefully we will start seeing more affordable POWER systems now that it is a fully open architecture
    - acqq 7y ago
      > with every single chip running auditable firmware But disks? Isn’t their firmware closed?
      - voldacar 7y ago
        Ugh I guess there always has to be an exception. Maybe you could run everything in a ramdisk? It supports up to 2TB of ram after all
      - justinclift 7y ago
        Maybe OpenSSD would be functional enough to use: http://openssd.io http://openssd.io http://www.openssd-project.org/wiki/The_OpenSSD_Project http://www.openssd-project.org/wiki/The_OpenSSD_Project
      - tpearson-raptor 7y ago
        What you can do with a trusted CPU domain is use FDE. FDE is standard practice for anyone even remotely concerned about security in the first place. So the firmware that matters -- the firmware that can subvert the system due to privilege level, etc. -- is open. No other vendor aside from some lower end ARM toy SoCs can say that.
cipherboy 7y ago
Fedora [0], Red Hat [1], Ubuntu [2], and SUSE [3] all have their own ppc64le ports as well so there are lots of choices out there if anyone is interested. Even Gentoo has one [4][5]! [0]: https://alt.fedoraproject.org/alt/ https://alt.fedoraproject.org/alt/ [1]: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html-single/8.0_release_notes/index#architectures https://access.redhat.com/documentation/en-us/red_hat_enterp... [2]: https://ubuntu.com/download/server/power https://ubuntu.com/download/server/power [3]: https://www.suse.com/products/power/ https://www.suse.com/products/power/ [4]: https://wiki.gentoo.org/wiki/Handbook:PPC64 https://wiki.gentoo.org/wiki/Handbook:PPC64 [5]: https://www.gentoo.org/downloads/ https://www.gentoo.org/downloads/
- classichasclass 7y ago
  Fedora 30 on this Talos II. Works well.
- _emacsomancer_ 7y ago
  Void Linux as well: https://www.talospace.com/2019/01/void-linux-goes-power9.html https://www.talospace.com/2019/01/void-linux-goes-power9.htm... Although it's not official at this point I don't think.
  - classichasclass 7y ago
    No, though my impression is it's progressing pretty well, so I think it will get there.
martin1975 7y ago
can you run AIX on it?
- CrystalGamma 7y ago
  No. AFAIK AIX only runs on PowerVM systems, which none of the OpenPOWER systems are.
  - Annatar 7y ago
    Then what's the point if I can't run AIX on it?!?
Annatar 7y ago
"Talos™ II 2U Rack Mount Server TL2SV1 Talos™ II 2U Rack Mount Server Starting at $6,089.00" Not at $6,089.00; they can forget that. It has to cost no more than $500 USD or this will be a repeat of the same mistake Sun Microsystems did. Will these companies ever learn? One cannot charge enterprise prices if one wants to build an upward spiral. Intel systems dominate because they are dirt cheap and convenient to buy.
- fluffything 7y ago
  You can't find a modern Intel Xeon Gold CPU for less than 2000$. If you buy 2, and a motherboard, you are already in the 6000$ ballpark, and then you still need to buy everything else (PSU, RAM, SSDs, GPGPU, etc.).
  - Annatar 7y ago
    I can build (and have) a fully decked-out intel-based 1U server for $1,800 USD, so this Talos thing can't compete: it's not cost-effective no matter how one slices and dices it. This company is repeating the same mistake IBM, hp, SGI and Sun before it made. Those who do not learn from history are doomed to repeat mistakes of those who came before them. Have you bought one of those Talos systems?
    - fluffything 7y ago
      I'll believe you if you are able to provide a link to two Xeon Gold CPUs costing the same or less than the 1800$ you claim you are able to build a full 1U rack with two of them.
jammygit 7y ago
Have you had any issues with it, or has it required any additional configuration? I'm extremely curious about the real world use of Power chips

blattimwind 7y ago

PowerPC and POWER are relatively mainstream. It's supported by IBM XL, GCC, Clang and most major JITs (including luajit).

floatboth 7y ago
> including luajit Well, a fork of luajit. LuaJIT proper has been abandoned for months…
- ksec 7y ago
  I thought somebody picked up as new maintainer and then Mike Pall was back. What happened? He lost interest?
  - jpfr 7y ago
    No new commits since January. https://github.com/LuaJIT/LuaJIT https://github.com/LuaJIT/LuaJIT
squarefoot 7y ago
Exactly. I can't speak for big iron and server usage because last time I used a POWER based server at work it was still AIX restricted (though IBM was already aiming at Linux for the future), however on PPC about everything user level was available 15 years ago, including USB devices support and compilers. When the very first PPC Mac Mini came out I purchased one to be used as a living room media PC connected to a projector and running a customized Debian which would load a media player (Freevo) just after boot. Worked like charm for years, no complains at all save for the atrocious loud "boonnnngggg" sound at power up that I was never able to turn off:^)

shawnz 7y ago

> POWER is a monster of an architecture, designed more for "big iron". It's the same architecture as PowerPC, designed for desktops, isn't it? Have things really changed so much since then?

yellowapple 7y ago
I wouldn't be surprised if they have, given that PowerPC desktops haven't been mainstream for more than a decade now, and in the meantime IBM's servers have been marching on.
- close04 7y ago
  The last truly mainstream PowerPC desktop was Apple's 2005 Quad-G5 PowerMac. There were other PowerPC machines after this, the PS3 being the most notable. But they were either not desktops or not mainstream. I'm a hardware nostalgic and have both gathering dust in my basement. So I can't wait for a PowerPC revival of any kind.
  - floatboth 7y ago
    Raptor Talos/Blackbird is a niche, expensive revival, but a revival nonetheless :)
    - close04 7y ago
      I may have been overly generous with the "of any kind" :). That's a bit on the expensive side and the ecosystem and platform flexibility in terms of upgrade are still pretty slim/locked in. Something that's open and cheap enough to spark general interest would be much more interesting.
      - yellowapple 7y ago
        The Blackbirds don't look too expensive, and Talos' hardware in general is about as open as it gets (putting even the x86 market to shame, let alone the PowerPC Apple desktops).

circuit 7y ago

- Where can I get a compiler? PGI has a free POWER compiler https://www.pgroup.com/products/community.htm https://www.pgroup.com/products/community.htm

zie 7y ago
LLVM and GCC both support POWER.

floatboth 7y ago

> all 1200 pages of it Sounds weak, one of the versions of ARMv8 has a spec that's exactly 6666 (!) pages. I would expect IBM to be more detailed lol

mhh__ 7y ago
Spec or manual? The ARM Spec I've seen is also 1200ish pages whereas the programmers manual is indeed thousands of pages
- floatboth 7y ago
  Ah, they indeed have a shorter spec, but it's at 2611 pages now https://static.docs.arm.com/ddi0596/d/ISA_A64_xml_v85A-2019-06_OPT.pdf https://static.docs.arm.com/ddi0596/d/ISA_A64_xml_v85A-2019-... It's actually a document generated from machine-readable XML files https://alastairreid.github.io/ARM-v8a-xml-release/ https://alastairreid.github.io/ARM-v8a-xml-release/
CrystalGamma 7y ago
IBM doesn't do wacky stuff like Pointer authentication that creeps into every corner of the spec, making everything more complicated …

ajross 7y ago

> POWER is a monster of an architecture FWIW: the original RS/6000 devices were 20-40 MHz in-order CPUs with architectures objectively simpler than a RISC-V microcontroller like the E310.

ksec 7y ago

And more questions, Correct me if I am wrong, So this is opening up of POWER ISA, since there is quite a few different version or Revision of that, I assume that is the one beings used in POWER9 and in the future POWER10? And it is more like RISC-V ISA open source rather than MIPS open source ?( I believe POWER was previously opened but with Cooperate Protection speak all over it ). And this does not include Implementations, like POWER9? I mean, if all of these were true, without implementation , or at leats licensing it for cheap, it still doesn't change the market one bit.

ajdlinux 7y ago

The toy soft-core VHDL model that is referred to there will be available at https://github.com/antonblanchard/microwatt https://github.com/antonblanchard/microwatt at some point in the next couple of days.