5 ms·

Reducing runtime memory in Windows 8

89 points by ghurlman 15y ago

acqq 15y ago
Interestingly, they don't mention their latest incarnation of "DLL hell," the multiple versions of the same libraries which are used by different pieces of their own system. http://blogs.technet.com/b/askcore/archive/2008/09/17/what-is-the-winsxs-directory-in-windows-2008-and-windows-vista-and-why-is-it-so-large.aspx http://blogs.technet.com/b/askcore/archive/2008/09/17/what-i... If they use a DLL version x for a component A and a version y for a component B, they raised memory usage only for convenience of not updating one of the components to use the latest version of the DLL.
- jeffreymcmanus 15y ago
  That's not "DLL Hell," it's an attempt to alleviate it.
  - wanorris 15y ago
    And it's a really good one. It's easy to ensure that all the system software or all of a particular package (e.g. Office) uses the same version of a DLL, but approximately impossible to ensure that all third-party software is always refreshed to use precisely the version that's loaded on a particular machine (where that version can very based on Windows release, service pack deployment, etc.). This is especially a problem in enterprise deployments where there may be a variety of spottily maintained internal and third-party applications loaded on a machine. Having to choose between refreshing every single one of them or throwing the unrefreshed ones out is an impractical choice. Thus DLL versioning. Avoid resulting problems by either maintaining your apps in a way that allows them to all use the same build of a DLL or simply by running as few apps as possible to minimize library loading in general, duplicate or otherwise.
- barista 15y ago
  The article talks about size on disk. Not how it gets loaded in memory.
  - sid0 15y ago
    Well, multiple versions of code being loaded means that there are fewer common pages to share across processes. However I think it is the right tradeoff to make.
emp_ 15y ago
Relevant: http://www.youtube.com/watch?v=lgU9cjUtrD4 http://www.youtube.com/watch?v=lgU9cjUtrD4 Windows 8 running on 128mb RAM.
- nextparadigms 15y ago
  "(loading time ~2-3h)." So, pointless demo. It probably run everything from the HDD.
  - blntechie 15y ago
    I'm not sure whether he meant the boot time here. May be the Windows 8 installation time. I could be wrong.
  - sliverstorm 15y ago
    S3 state?
mcastner 15y ago
I'm starting to believe that memory usage may be a red herring in modern operating systems. Memory prices have been crashing, every day on Slickdeals I see 8GB of notebook (and netbook) memory for less than $30. Is this a problem worth solving anymore?
- mcastner 15y ago
  Oh I should've read the whole article first...apparently reduced memory usage leads to longer battery life which is a worthy goal.
  - binarycrusader 15y ago
    Right. CPUs and other components of the system now use relatively little power in many cases or at least far less than they used to. However, RAM remains one of the largest power consumers, and so reducing memory usage also reduces power usage, which improves battery life. Tom's hardware has a great article on this here: http://www.tomshardware.com/reviews/lovo-ddr3-power,2650-2.html http://www.tomshardware.com/reviews/lovo-ddr3-power,2650-2.h... Note in particular the figures at the bottom of the article page.
    - Someone 15y ago
      When I read that, I wondered how long we will keep using DRAM in mobile devices. If Moore's law holds, we will easily be able to put 10GB of DRAM in a phone in ten years. I think having 1 GB of static RAM might be preferable.
      - adgar 15y ago
        If 1 GB of static ram were even remotely cheap enough and dense enough, our processors would have more than a few megs of L1-3 combined cache. Especially since high-end processors cost hundreds of dollars already.
        sliverstorm 15y ago
gburt 15y ago
This seems largely misguided. Stuff like merging duplicate memory spots (such as that reserved for future use by applications) seems to question programmer judgment in the aim of saving available memory. If the memory is available, you'd do better to use it, no?
- singh 15y ago
  How is this misguided? > If the application tries to write to the memory in future, Windows will give it a private copy It is textbook Copy-on-write. To me it seems no judgement is made about the programmer. >If the memory is available, you'd do better to use it, no? I don't understand... if I have 2 GB of RAM, I should always use all of it? The case being made in the article is to minimize memory consumption to increase battery life - something that will be crucial on tablets I assume.
- wmf 15y ago
  ...question programmer judgment in the aim of saving available memory. These are Windows programmers we're talking about. The culture doesn't seem to encourage fastidiousness. If the memory is available, you'd do better to use it, no? Yes, but what if you run out later? Should you do the dedupe when some other process is blocked trying to allocate memory or should you do it earlier?
- dorian-graph 15y ago
  It seems like everyone and his grandma know better than Microsoft engineers.
sliverstorm 15y ago
For all the negative reputations Windows has aquired, it really seems like the architects of 7 & 8 are taking this seriously and doing some real Computer Science. This is some really good stuff.

89 points by ghurlman 15y ago

acqq 15y ago

Interestingly, they don't mention their latest incarnation of "DLL hell," the multiple versions of the same libraries which are used by different pieces of their own system. http://blogs.technet.com/b/askcore/archive/2008/09/17/what-is-the-winsxs-directory-in-windows-2008-and-windows-vista-and-why-is-it-so-large.aspx http://blogs.technet.com/b/askcore/archive/2008/09/17/what-i... If they use a DLL version x for a component A and a version y for a component B, they raised memory usage only for convenience of not updating one of the components to use the latest version of the DLL.

jeffreymcmanus 15y ago
That's not "DLL Hell," it's an attempt to alleviate it.
- wanorris 15y ago
  And it's a really good one. It's easy to ensure that all the system software or all of a particular package (e.g. Office) uses the same version of a DLL, but approximately impossible to ensure that all third-party software is always refreshed to use precisely the version that's loaded on a particular machine (where that version can very based on Windows release, service pack deployment, etc.). This is especially a problem in enterprise deployments where there may be a variety of spottily maintained internal and third-party applications loaded on a machine. Having to choose between refreshing every single one of them or throwing the unrefreshed ones out is an impractical choice. Thus DLL versioning. Avoid resulting problems by either maintaining your apps in a way that allows them to all use the same build of a DLL or simply by running as few apps as possible to minimize library loading in general, duplicate or otherwise.
barista 15y ago
The article talks about size on disk. Not how it gets loaded in memory.
- sid0 15y ago
  Well, multiple versions of code being loaded means that there are fewer common pages to share across processes. However I think it is the right tradeoff to make.

emp_ 15y ago

Relevant: http://www.youtube.com/watch?v=lgU9cjUtrD4 http://www.youtube.com/watch?v=lgU9cjUtrD4 Windows 8 running on 128mb RAM.

nextparadigms 15y ago
"(loading time ~2-3h)." So, pointless demo. It probably run everything from the HDD.
- blntechie 15y ago
  I'm not sure whether he meant the boot time here. May be the Windows 8 installation time. I could be wrong.
- sliverstorm 15y ago
  S3 state?

mcastner 15y ago

I'm starting to believe that memory usage may be a red herring in modern operating systems. Memory prices have been crashing, every day on Slickdeals I see 8GB of notebook (and netbook) memory for less than $30. Is this a problem worth solving anymore?

mcastner 15y ago
Oh I should've read the whole article first...apparently reduced memory usage leads to longer battery life which is a worthy goal.
- binarycrusader 15y ago
  Right. CPUs and other components of the system now use relatively little power in many cases or at least far less than they used to. However, RAM remains one of the largest power consumers, and so reducing memory usage also reduces power usage, which improves battery life. Tom's hardware has a great article on this here: http://www.tomshardware.com/reviews/lovo-ddr3-power,2650-2.html http://www.tomshardware.com/reviews/lovo-ddr3-power,2650-2.h... Note in particular the figures at the bottom of the article page.
  - Someone 15y ago
    When I read that, I wondered how long we will keep using DRAM in mobile devices. If Moore's law holds, we will easily be able to put 10GB of DRAM in a phone in ten years. I think having 1 GB of static RAM might be preferable.
    - adgar 15y ago
      If 1 GB of static ram were even remotely cheap enough and dense enough, our processors would have more than a few megs of L1-3 combined cache. Especially since high-end processors cost hundreds of dollars already.
      - sliverstorm 15y ago

gburt 15y ago

This seems largely misguided. Stuff like merging duplicate memory spots (such as that reserved for future use by applications) seems to question programmer judgment in the aim of saving available memory. If the memory is available, you'd do better to use it, no?

singh 15y ago
How is this misguided? > If the application tries to write to the memory in future, Windows will give it a private copy It is textbook Copy-on-write. To me it seems no judgement is made about the programmer. >If the memory is available, you'd do better to use it, no? I don't understand... if I have 2 GB of RAM, I should always use all of it? The case being made in the article is to minimize memory consumption to increase battery life - something that will be crucial on tablets I assume.
wmf 15y ago
...question programmer judgment in the aim of saving available memory. These are Windows programmers we're talking about. The culture doesn't seem to encourage fastidiousness. If the memory is available, you'd do better to use it, no? Yes, but what if you run out later? Should you do the dedupe when some other process is blocked trying to allocate memory or should you do it earlier?
dorian-graph 15y ago
It seems like everyone and his grandma know better than Microsoft engineers.

sliverstorm 15y ago

For all the negative reputations Windows has aquired, it really seems like the architects of 7 & 8 are taking this seriously and doing some real Computer Science. This is some really good stuff.