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Moving beyond a 64-bit architecture will allow manipulation of memory address spaces that are larger than 16 Exabytes. Even high-end servers today do not contai

by aogl 8y ago

Moving beyond a 64-bit architecture will allow manipulation of memory address spaces that are larger than 16 Exabytes. Even high-end servers today do not contain more than 1TB of physical memory. It would take several decades if not more for memory densities to become high enough to begin to reach the boundary that 64-bit addressing limits computers. So yes, highly likely for a little while..

magoghm 8y ago
You can have an AWS instance with up to 12 TB of RAM: https://aws.amazon.com/blogs/aws/now-available-amazon-ec2-high-memory-instances-with-6-9-and-12-tb-of-memory-perfect-for-sap-hana/ https://aws.amazon.com/blogs/aws/now-available-amazon-ec2-hi...
stochastic_monk 8y ago
Current x86 architectures only use 48 bits for addressing. That’s still enough to address ~280TB of RAM. I expect that to change before upgrading to 128-bit pointers.
- red75prime 8y ago
  128 bits are nearly enough to address every atom in the Universe. Such pointers are mostly a waste of memory space. > I expect that to change before upgrading to 128-bit pointers. Or the joke was wasted on me. Did you mean it will never be feasible?
geocar 8y ago
People where I work have workstations with more than 1TB of ram. I think the value of a larger pointer (immediately) would be tags, not memory density, just as it was with 64-bit systems -- my old Alpha only had 256mb of ram, and maxed out at 512mb IIRC.
- mehrdadn 8y ago
  > People where I work have workstations with more than 1TB of ram. Wow. What kinds of workstation tasks need this kind of memory, if I may ask?
  - colejohnson66 8y ago
    Virtual machines?
    - mehrdadn 8y ago
      For workstations though? Not servers?
  - wl 8y ago
    Genome assembly and computational fluid dynamics are the two that come immediately to mind.
    - mehrdadn 8y ago
      Wow. They need that much data in memory at once? I could understand needing a ton of secondary storage for both, but this much primary storage would seem to imply they need random access to terabytes of data which is a little huge to swallow!!
  - geocar 8y ago
    Analysis; some model building. It is popular to buy a bunch of servers (or worse, host them on AWS), a bunch of sysadmins, and so on, so you can support a couple smart analysts with some complex hadoop java streaming somethingrather, but it is much cheaper to just buy them beefy workstations and use awk: A HP Z8 G4 with 1.5TB ram is under £30k, and it's hard to get a sysadmin that has any brains for that, let alone two and servers...
mitchty 8y ago
> Even high-end servers today do not contain more than 1TB of physical memory. ??? I know of multiple high end servers with 1TiB+ memory footprints. What is your definition of high end? Here, have a look at HP's page if you don't believe me: https://www.hpe.com/us/en/product-catalog/servers/proliant-servers.hits-12.html https://www.hpe.com/us/en/product-catalog/servers/proliant-s... And I'd hardly consider those "high end", there are much larger memory servers out there if you want them.

by aogl 8y ago

magoghm 8y ago

You can have an AWS instance with up to 12 TB of RAM: https://aws.amazon.com/blogs/aws/now-available-amazon-ec2-high-memory-instances-with-6-9-and-12-tb-of-memory-perfect-for-sap-hana/ https://aws.amazon.com/blogs/aws/now-available-amazon-ec2-hi...

stochastic_monk 8y ago

Current x86 architectures only use 48 bits for addressing. That’s still enough to address ~280TB of RAM. I expect that to change before upgrading to 128-bit pointers.

red75prime 8y ago
128 bits are nearly enough to address every atom in the Universe. Such pointers are mostly a waste of memory space. > I expect that to change before upgrading to 128-bit pointers. Or the joke was wasted on me. Did you mean it will never be feasible?

geocar 8y ago

People where I work have workstations with more than 1TB of ram. I think the value of a larger pointer (immediately) would be tags, not memory density, just as it was with 64-bit systems -- my old Alpha only had 256mb of ram, and maxed out at 512mb IIRC.

mehrdadn 8y ago
> People where I work have workstations with more than 1TB of ram. Wow. What kinds of workstation tasks need this kind of memory, if I may ask?
- colejohnson66 8y ago
  Virtual machines?
  - mehrdadn 8y ago
    For workstations though? Not servers?
- wl 8y ago
  Genome assembly and computational fluid dynamics are the two that come immediately to mind.
  - mehrdadn 8y ago
    Wow. They need that much data in memory at once? I could understand needing a ton of secondary storage for both, but this much primary storage would seem to imply they need random access to terabytes of data which is a little huge to swallow!!
- geocar 8y ago
  Analysis; some model building. It is popular to buy a bunch of servers (or worse, host them on AWS), a bunch of sysadmins, and so on, so you can support a couple smart analysts with some complex hadoop java streaming somethingrather, but it is much cheaper to just buy them beefy workstations and use awk: A HP Z8 G4 with 1.5TB ram is under £30k, and it's hard to get a sysadmin that has any brains for that, let alone two and servers...

mitchty 8y ago

> Even high-end servers today do not contain more than 1TB of physical memory. ??? I know of multiple high end servers with 1TiB+ memory footprints. What is your definition of high end? Here, have a look at HP's page if you don't believe me: https://www.hpe.com/us/en/product-catalog/servers/proliant-servers.hits-12.html https://www.hpe.com/us/en/product-catalog/servers/proliant-s... And I'd hardly consider those "high end", there are much larger memory servers out there if you want them.