7 ms·

I know, this discussion is quite old (e.g. Mac vs. PC), but can you clarify how you define PC in your post? Particularly what makes this RISC-V board a PC, wha

by bipson 6y ago

I know, this discussion is quite old (e.g. Mac vs. PC), but can you clarify how you define PC in your post? Particularly what makes this RISC-V board a PC, what an RPi does not have? Form factor, ATX power or PCI-Express?

justaguy88 6y ago
This isn't a Mac vs PC comparison, its embedded form factor and vs standard form factor with standard connectors
- bipson 6y ago
  I didn't say it was. I was just wondering how you define PC. Form factor or "standard connectors" (whatever that is - which RPi connector is not "standard"?) are none of my criteria.
  - brucehoult 6y ago
    "PC": ability to use any commodity Mini-ITX PC case, commodity power supply, standard PCie video card, standard M.2 SSD.
    - bipson 6y ago
      I'm getting frustrated here. Could you guys stop for a second pretending that your "opponent" is dumb and try to look outside the box? Again, to me this are entirely arbitrary criteria. They are not "PC-Standards", they are some of many standardized connectors, form factors, etc. and in fact a matter of habit, not defining criteria. Let me put it differently: - So is a DTX-Board with an ARM-SoC a PC? - Is an ATX-Board with a PowerPC but without PCIe a PC? What if we add PCIe? - Is a SBC with an AMD APU powered by an USB power supply a PC? What if we add an M.2 port? See where I am going? These are terrible criteria. Define PC for me.
      - ido 6y ago
        I don't think they pretend you are dumb. As someone who is relatively a lay-person (as in - I know computers but I'm not a hardware person) I understand the difference as "can I buy some standard components off of amazon/ebay and lego-build a computer with fairly powerful components like geforce/radeon type GPUs and m.2 storage" or is something that's basically a sealed box/board (aside from more advanced stuff I won't do, like soldering chips to a PCB) and/or doesn't have access to desktop class components (as far as I'm aware you can't reasonably stick a desktop GPU on an rpi).
      - tmzt 6y ago
        The entire ecosystem surrounding modern descendents of the IBM PC compatible. Normally this would also imply an Intel isa, which dictated a multi-component chipset. (North bridge/South bridge) this in turn implies an multi-voltage power supply with a standard plug or plugs derived from the one in the PC AT. The PC ecosystem also features a set of peripherals, such as floppy drives, hard drives, and CD-ROM drives. These peripherals have their own busses, starting with MFM, and now IDE and SATA. In some cases SCSI entered into the mix, but most consumer-oriented PCs did not use it. These drives were also were powered by the same power supply as the rest of the PC, with an evolving set of connectors and electrical standards. The Mac took a parallel course, but featured it's own set of proprietary connectors and buses, as well as SCSI, for years before converging with the PC ecosystem in part in later years. Many of these de-facto and cloned standards were adopted by standards organizations, such as EIA/TIA and IEEE. They were joined by PCI buses, which were used in a diverse set of architectures, including Sun. Later serial variants were developed for the PC and Mac ecosystems, driven by demand for faster graphics accelerators, with a side jaunt to AGP. At the same time, emdedded devices evolved around a simpler usually single-chip chipset, and often single voltage board designs, with the exception of the cpu core voltage in some cases. These largely used memory-mapped IO with periphrial chips coupled to the memory bus, as well as slower buses such as I2C and SPI. These devices were usually power constrained, having quickly moved into the mobile realm with early PDAs such as the Newton. They mostly developed around the ARM chip which so low power in the early versions that it could run without voltage on it's primary bus. As the PC ecosystem has evolved, it is now largely built around the PCI bus. PCI is cpu agnostic, so the CPU can be replaced with a different isa while keeping the rest of the system intact. The PC is also historically modular, so substitutions such as those you suggested can generally be made while keeung the PC nature of the system. M.2 is a modern bus that has veen adopted into the ecosystem primarily for laptops, though also featured in some desktops. Modern emedded devices are begininning to feature PCI interfaces, though these are only recently appearing in consumer electronics. They have been used in storage-centric chipsets for much longer. The PC also implies a modular memory bus, with chips or modules complying with a logical and electrical standard, and identifying chip that can be probed by the chipset. In some cases the modularity is reduced and the chips are soldered to the mainboard. PCs have also begun to adopt single-chip chipsets and System-on-Chip designs, starting with some emdedded intel designs used in mobile tablets and the UMPC. These brought the classic north bridge and south bridge as well as graphics (in this case PowerVR coming from the emdedded world). AMD64 chips also began to include the memory controller on die, leading up to the mentioned APUs that can be powered with the help of a standard embedded power IC from a single low voltage source.
giantrobot 6y ago
The main thing I think would be simply enumerable buses and support for the APCI root bus instead of the more embedded focused device tree.
- monocasa 6y ago
  Device tree doesn't really have an embedded focus per se. It comes from Sparc and PowerPC workstations. And ACPI doesn't really have a standard root bus, it's a soup of descriptor tables and virtual machine blobs you have to run and trust, along with veritable mountains of patches for those vm bytecodes to fix firmware issues. IMO Device Tree is the right way to go for nearly all platforms.
  - AnthonyMouse 6y ago
    I'm going to try to describe something I only half understand in the hopes that someone who does fully understand it will come by and provide a better description. For normal PC hardware, you have a SATA controller, the device company commits a driver for it to the Linux kernel tree, and thereafter every subsequent version of Linux can use the SATA controller in any device with that kind of SATA controller. If the device company doesn't provide a driver but the hardware is popular, somebody else reverse engineers the chip and eventually the same result obtains. Likewise for the network controller, the GPU and so on. Typical ARM devices like cellphones are beleaguered by some kind of shameful omnishambles whereby that doesn't work. The device maker provides a hideous binary blob with the device, it only works with that specific kernel version and everything is terrible. The exact source of the tragedy is the part I'm not quite clear on. But making whatever that is not apply to RISC-V boards would be highly satisfactory.
    - monocasa 6y ago
      It "doesn't work" on ARM simply do to the extreme heterogenity. To ask for otherwise would be asking for AMD drivers to work for an Nvidia graphics card. Additionally, PCs do in fact of tons of glue and support systems that match how ARM style SoCs work. They paper over it with ACPI which is based around a VM that has to be run in the kernel that's basically a giant binary blob, in contrast to device tree's description of the components and how they're connected.
m463 6y ago
Use a standard power supply, put it in a case and maybe develop on it. and pci-express opens up possibilities the pi (not compute) doesn't really have access to. I have many pis that I love, but you have to admit, there are a few compromises made for a lower bom cost. That is not a requirement for a $600+ board.
- freeopinion 6y ago
  Pi uses a standard power supply. You can put a Pi in a case. In fact, it's hard to find one on Amazon without a case. Of course you can develop on it. That's the whole point. Pi 4 has pci-express, no?
  - m463 6y ago
    I struggled with a power supply for the pi all the way up to the pi 4 - always getting the low power indicator. I struggled with the pi SD card - extremely slow and always the possibility of corruption. I struggled with pi graphics - none of my projects every had accelerated graphics, not even blits. I struggled with pi USB - at first it was power and speed, now it might be in better shape but not all the way there. The pi is still limited to ~ 15w. When you get to the pc ecosystem, and it's really just a bit more expensive, you get a step up in capabilities. You get all the voltages. You can get a 300w or a 1500w power supply. You can add a graphics card. You can put it in a case that has room for more than just the board. Say, I/O? I wish the pi had a nice metal case that had a 2x the width allowing for an enclosed breadboard or the like. Or a case with all the connectors on one side. > Pi 4 has pci-express, no? really? where is the slot? (I said not compute) ;) btw, I'm not anti-pi, the opposite in fact. Maybe I could say it in another way -- what if you could have an itx form-factor pi? I think that would be very exciting.
  - CrazyPyroLinux 6y ago
    > Pi 4 has pci-express, no? Not the pi, but the vaguely-similar (better, IMHO) https://www.pine64.org/rockpro64/ https://www.pine64.org/rockpro64/ has a 4x pcie. Works great for a sata/raid controller, but still has plenty of "embedded" limitations - you can't just plug a graphics card into it.

by bipson 6y ago

justaguy88 6y ago

This isn't a Mac vs PC comparison, its embedded form factor and vs standard form factor with standard connectors

bipson 6y ago
I didn't say it was. I was just wondering how you define PC. Form factor or "standard connectors" (whatever that is - which RPi connector is not "standard"?) are none of my criteria.
- brucehoult 6y ago
  "PC": ability to use any commodity Mini-ITX PC case, commodity power supply, standard PCie video card, standard M.2 SSD.
  - bipson 6y ago
    I'm getting frustrated here. Could you guys stop for a second pretending that your "opponent" is dumb and try to look outside the box? Again, to me this are entirely arbitrary criteria. They are not "PC-Standards", they are some of many standardized connectors, form factors, etc. and in fact a matter of habit, not defining criteria. Let me put it differently: - So is a DTX-Board with an ARM-SoC a PC? - Is an ATX-Board with a PowerPC but without PCIe a PC? What if we add PCIe? - Is a SBC with an AMD APU powered by an USB power supply a PC? What if we add an M.2 port? See where I am going? These are terrible criteria. Define PC for me.
    - ido 6y ago
      I don't think they pretend you are dumb. As someone who is relatively a lay-person (as in - I know computers but I'm not a hardware person) I understand the difference as "can I buy some standard components off of amazon/ebay and lego-build a computer with fairly powerful components like geforce/radeon type GPUs and m.2 storage" or is something that's basically a sealed box/board (aside from more advanced stuff I won't do, like soldering chips to a PCB) and/or doesn't have access to desktop class components (as far as I'm aware you can't reasonably stick a desktop GPU on an rpi).
    - tmzt 6y ago
      The entire ecosystem surrounding modern descendents of the IBM PC compatible. Normally this would also imply an Intel isa, which dictated a multi-component chipset. (North bridge/South bridge) this in turn implies an multi-voltage power supply with a standard plug or plugs derived from the one in the PC AT. The PC ecosystem also features a set of peripherals, such as floppy drives, hard drives, and CD-ROM drives. These peripherals have their own busses, starting with MFM, and now IDE and SATA. In some cases SCSI entered into the mix, but most consumer-oriented PCs did not use it. These drives were also were powered by the same power supply as the rest of the PC, with an evolving set of connectors and electrical standards. The Mac took a parallel course, but featured it's own set of proprietary connectors and buses, as well as SCSI, for years before converging with the PC ecosystem in part in later years. Many of these de-facto and cloned standards were adopted by standards organizations, such as EIA/TIA and IEEE. They were joined by PCI buses, which were used in a diverse set of architectures, including Sun. Later serial variants were developed for the PC and Mac ecosystems, driven by demand for faster graphics accelerators, with a side jaunt to AGP. At the same time, emdedded devices evolved around a simpler usually single-chip chipset, and often single voltage board designs, with the exception of the cpu core voltage in some cases. These largely used memory-mapped IO with periphrial chips coupled to the memory bus, as well as slower buses such as I2C and SPI. These devices were usually power constrained, having quickly moved into the mobile realm with early PDAs such as the Newton. They mostly developed around the ARM chip which so low power in the early versions that it could run without voltage on it's primary bus. As the PC ecosystem has evolved, it is now largely built around the PCI bus. PCI is cpu agnostic, so the CPU can be replaced with a different isa while keeping the rest of the system intact. The PC is also historically modular, so substitutions such as those you suggested can generally be made while keeung the PC nature of the system. M.2 is a modern bus that has veen adopted into the ecosystem primarily for laptops, though also featured in some desktops. Modern emedded devices are begininning to feature PCI interfaces, though these are only recently appearing in consumer electronics. They have been used in storage-centric chipsets for much longer. The PC also implies a modular memory bus, with chips or modules complying with a logical and electrical standard, and identifying chip that can be probed by the chipset. In some cases the modularity is reduced and the chips are soldered to the mainboard. PCs have also begun to adopt single-chip chipsets and System-on-Chip designs, starting with some emdedded intel designs used in mobile tablets and the UMPC. These brought the classic north bridge and south bridge as well as graphics (in this case PowerVR coming from the emdedded world). AMD64 chips also began to include the memory controller on die, leading up to the mentioned APUs that can be powered with the help of a standard embedded power IC from a single low voltage source.

giantrobot 6y ago

The main thing I think would be simply enumerable buses and support for the APCI root bus instead of the more embedded focused device tree.

monocasa 6y ago
Device tree doesn't really have an embedded focus per se. It comes from Sparc and PowerPC workstations. And ACPI doesn't really have a standard root bus, it's a soup of descriptor tables and virtual machine blobs you have to run and trust, along with veritable mountains of patches for those vm bytecodes to fix firmware issues. IMO Device Tree is the right way to go for nearly all platforms.
- AnthonyMouse 6y ago
  I'm going to try to describe something I only half understand in the hopes that someone who does fully understand it will come by and provide a better description. For normal PC hardware, you have a SATA controller, the device company commits a driver for it to the Linux kernel tree, and thereafter every subsequent version of Linux can use the SATA controller in any device with that kind of SATA controller. If the device company doesn't provide a driver but the hardware is popular, somebody else reverse engineers the chip and eventually the same result obtains. Likewise for the network controller, the GPU and so on. Typical ARM devices like cellphones are beleaguered by some kind of shameful omnishambles whereby that doesn't work. The device maker provides a hideous binary blob with the device, it only works with that specific kernel version and everything is terrible. The exact source of the tragedy is the part I'm not quite clear on. But making whatever that is not apply to RISC-V boards would be highly satisfactory.
  - monocasa 6y ago
    It "doesn't work" on ARM simply do to the extreme heterogenity. To ask for otherwise would be asking for AMD drivers to work for an Nvidia graphics card. Additionally, PCs do in fact of tons of glue and support systems that match how ARM style SoCs work. They paper over it with ACPI which is based around a VM that has to be run in the kernel that's basically a giant binary blob, in contrast to device tree's description of the components and how they're connected.

m463 6y ago

Use a standard power supply, put it in a case and maybe develop on it. and pci-express opens up possibilities the pi (not compute) doesn't really have access to. I have many pis that I love, but you have to admit, there are a few compromises made for a lower bom cost. That is not a requirement for a $600+ board.

freeopinion 6y ago
Pi uses a standard power supply. You can put a Pi in a case. In fact, it's hard to find one on Amazon without a case. Of course you can develop on it. That's the whole point. Pi 4 has pci-express, no?
- m463 6y ago
  I struggled with a power supply for the pi all the way up to the pi 4 - always getting the low power indicator. I struggled with the pi SD card - extremely slow and always the possibility of corruption. I struggled with pi graphics - none of my projects every had accelerated graphics, not even blits. I struggled with pi USB - at first it was power and speed, now it might be in better shape but not all the way there. The pi is still limited to ~ 15w. When you get to the pc ecosystem, and it's really just a bit more expensive, you get a step up in capabilities. You get all the voltages. You can get a 300w or a 1500w power supply. You can add a graphics card. You can put it in a case that has room for more than just the board. Say, I/O? I wish the pi had a nice metal case that had a 2x the width allowing for an enclosed breadboard or the like. Or a case with all the connectors on one side. > Pi 4 has pci-express, no? really? where is the slot? (I said not compute) ;) btw, I'm not anti-pi, the opposite in fact. Maybe I could say it in another way -- what if you could have an itx form-factor pi? I think that would be very exciting.
- CrazyPyroLinux 6y ago
  > Pi 4 has pci-express, no? Not the pi, but the vaguely-similar (better, IMHO) https://www.pine64.org/rockpro64/ https://www.pine64.org/rockpro64/ has a 4x pcie. Works great for a sata/raid controller, but still has plenty of "embedded" limitations - you can't just plug a graphics card into it.