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Better performance, and yes, it won't be long now before mobile devices ship with more than 4GB of memory. Don't forget AMD's announcement about ARM64 based se

Better performance, and yes, it won't be long now before mobile devices ship with more than 4GB of memory. Don't forget AMD's announcement about ARM64 based servers.

mbell 14y ago
ARM64 isn't required for > 4GB physical memory. The cortex-a15 can already address up to 1TB and is already shipping. Only the per process limit is locked to 4GB on a 32 bit core.
- binarycrusader 14y ago
  I think you're splitting hairs. In fairness, I didn't explicitly call that out, but as soon as you have more than 4GB of memory, there's going to be an application that wants to use more than 4GB. So yes, 64-bit is necessary in my opinion. Especially when you consider the server market.
  - mbell 14y ago
    > but as soon as you have more than 4GB of memory, there's going to be an application that wants to use more than 4GB Maybe, but my desktop has 32GB of ram, has a 64bit CPU, and I've rarely seen a single process use 4GB of memory unless it was leaking memory. My laptop has 8GB of ram, also 64bit, and I'm pretty sure I've never had a single process use 4GB. The only exception I can think of was doing some silly data manipulation, e.g. doing the initial build of a property graph of the entire Boston area transit system. I bet some high end games or video/photo editing software would use more than 4GB. Point is, those are all pretty niche situations, I'd bet the majority of memory usage on an average person's computer comes from browser processes, few hundred MB each if that and office applications, also a few hundred MB. Those processes add up though, so having more ram is usually a really good thing even if no processes uses even close to 4GB. I also challenge the need in server loads. I'd bet the vast majority of applications never use 4GB either on the app server or the database server. Most of what gets discussed here on HN are large high scalability applications that you wouldn't host on ARM cores anyway. We often forget that the vast majority of website are tiny and low traffic.
    - xradionut 14y ago
      In memory databases would be one good use for large amounts of system RAM even on ARM. You wouldn't suffer the IO cost of going to disk...
    - noselasd 14y ago
      Datacenters have a lot of stuff running in them. Big servers and databases arn't just for public facing large scale applications. Database servers in particular wants as much memory as possible, and it doesn't take that big of a business support application that have a working set of data > 4Gb. Same goes for a lot of the memory hungry Java application servers that sits around in a lot of businesses.
      - mbell 14y ago
        Apparently we're crossing wires here. I'm in no way shape or form saying these applications don't exist (I'm currently writing one). What I am saying is that for ever such application there are probably more than a thousand sites hosted on free with your domain or $5 a month php + mysql hosting that use no where near 4GB per process. For the companies hosting those sites a cortex a-15 with a ton of ram is an awesome solution. This isn't all or nothing, we're talking about two different markets.
        sliverstorm 14y ago
        But how does "64bit is needed in specific applications that are not the majority" translate to "64bit is not needed"?
        mbell 14y ago
        It doesn't, and I don't see where I've made that claim. I'm refuting the opposite. The initial claim was: > I didn't explicitly call that out, but as soon as you have more than 4GB of memory, there's going to be an application that wants to use more than 4GB. So yes, 64-bit is necessary in my opinion. Especially when you consider the server market. I'm just saying I don't agree. There is a massive market very open to the power saving offered by arm that have no use for > 4GB process spaces. That doesn't mean there aren't markets where 64bit will be useful.

Better performance, and yes, it won't be long now before mobile devices ship with more than 4GB of memory. Don't forget AMD's announcement about ARM64 based servers.

mbell 14y ago

ARM64 isn't required for > 4GB physical memory. The cortex-a15 can already address up to 1TB and is already shipping. Only the per process limit is locked to 4GB on a 32 bit core.

binarycrusader 14y ago
I think you're splitting hairs. In fairness, I didn't explicitly call that out, but as soon as you have more than 4GB of memory, there's going to be an application that wants to use more than 4GB. So yes, 64-bit is necessary in my opinion. Especially when you consider the server market.
- mbell 14y ago
  > but as soon as you have more than 4GB of memory, there's going to be an application that wants to use more than 4GB Maybe, but my desktop has 32GB of ram, has a 64bit CPU, and I've rarely seen a single process use 4GB of memory unless it was leaking memory. My laptop has 8GB of ram, also 64bit, and I'm pretty sure I've never had a single process use 4GB. The only exception I can think of was doing some silly data manipulation, e.g. doing the initial build of a property graph of the entire Boston area transit system. I bet some high end games or video/photo editing software would use more than 4GB. Point is, those are all pretty niche situations, I'd bet the majority of memory usage on an average person's computer comes from browser processes, few hundred MB each if that and office applications, also a few hundred MB. Those processes add up though, so having more ram is usually a really good thing even if no processes uses even close to 4GB. I also challenge the need in server loads. I'd bet the vast majority of applications never use 4GB either on the app server or the database server. Most of what gets discussed here on HN are large high scalability applications that you wouldn't host on ARM cores anyway. We often forget that the vast majority of website are tiny and low traffic.
  - xradionut 14y ago
    In memory databases would be one good use for large amounts of system RAM even on ARM. You wouldn't suffer the IO cost of going to disk...
  - noselasd 14y ago
    Datacenters have a lot of stuff running in them. Big servers and databases arn't just for public facing large scale applications. Database servers in particular wants as much memory as possible, and it doesn't take that big of a business support application that have a working set of data > 4Gb. Same goes for a lot of the memory hungry Java application servers that sits around in a lot of businesses.
    - mbell 14y ago
      Apparently we're crossing wires here. I'm in no way shape or form saying these applications don't exist (I'm currently writing one). What I am saying is that for ever such application there are probably more than a thousand sites hosted on free with your domain or $5 a month php + mysql hosting that use no where near 4GB per process. For the companies hosting those sites a cortex a-15 with a ton of ram is an awesome solution. This isn't all or nothing, we're talking about two different markets.
      - sliverstorm 14y ago
        But how does "64bit is needed in specific applications that are not the majority" translate to "64bit is not needed"?
        mbell 14y ago
        It doesn't, and I don't see where I've made that claim. I'm refuting the opposite. The initial claim was: > I didn't explicitly call that out, but as soon as you have more than 4GB of memory, there's going to be an application that wants to use more than 4GB. So yes, 64-bit is necessary in my opinion. Especially when you consider the server market. I'm just saying I don't agree. There is a massive market very open to the power saving offered by arm that have no use for > 4GB process spaces. That doesn't mean there aren't markets where 64bit will be useful.