Why Win 7 64bit has a limit of 192Gb RAM?

[antares]

If a 64bit OS can use up to 8Tb, why is it that Win7 64bit can only use up to 192Gb and not 8Tb?

 

[DustSailor]

Because it is a software limitation.

Are you getting RAM confused with virtual address space? - http://en.wikipedia.org/wiki/Virtual_address_space

Besides that, you won't find any home-user motherboard with enough space for that much RAM. Nor will you ever need it. If 8GB is 'really fast' today, and 2GB was 'really fast' some time ago, think just how long it would take in years for 8TB to be useful as a 'really fast' gaming system. Not in your lifetime, nor your childrens'.

• 8 TB of "user mode" virtual address space per process. A x64 program can use all of this, subject of course to backing-store limits on the system, and provided it is linked with the "large address aware" option.[53] This is a 4096-fold increase over the default 2 GB user-mode virtual address space offered by 32-bit Windows.[54][55]
• 8 TB of kernel mode virtual address space for the operating system.[54] As with the user mode address space, this is a 4096-fold increase over 32-bit Windows versions. The increased space primarily benefits the file-system cache and kernel-mode "heaps" (non-paged pool and paged pool). Windows only uses a total of 16 TB out of the 256 TB implemented by the processors because early AMD64 processors lacked a CMPXCHG16B instruction.[56]

Windows Server 2012 can use up to 4TB RAM

x86-64 - Wikipedia, the free encyclopedia

 

[dejavecue]

If a 64bit OS can use up to 8Tb, why is it that Win7 64bit can only use up to 192Gb and not 8Tb?

Just because something can be done, does not mean it makes sense (at this time). That is why you don't see overclocked CPUs with liquid nitrogen cooling in any computer store. Yes, it allows for extremely high clock speeds, but it just plain is not useful.

When we get around to 192GB of RAM as a normal amount of RAM in home computers, I doubt we will still use Windows 7. And even then Microsoft could probably just patch it out. For now it's just senseless to ask for this kind of RAM amount.

 

[yehuda]

Lol. 16Gb starting to be expensive. And the 32Gb are expensive can't imangine how much cost 192Gb not mantion have no clue why do you need that number.

 

[antares]

Hi all, not that I need 8Tb RAM lol, I was just curious from a theoretical viewpoint as to why that limitation was imposed in Win7 or if it was an actual technical hurdle. Anyway, I only have 2Gb currently in an 11 year old P4 XP PC. I would be more than happy with 16Gb RAM.

 

[rraod]

Dell offers PC that packs 192GB of DDR3 RAM [not a typo]

Estimated cost of this PC is around $50,000 !!!

 

[antares]

Dell offers PC that packs 192GB of DDR3 RAM [not a typo]

Estimated cost of this PC is around $50,000 !!!

That article is dated March 2009. RAM prices have come down drastically, not to say that 192Gb is "cheap", but it should be less than half of that price

 

[boogieboy]

8GB is more than enough for me and who in the world needs 192GB of RAM?

Answer: Nobody.

 

[dejavecue]

8GB is more than enough for me and who in the world needs 192GB of RAM?

Answer: Nobody.

I upgraded roughly 1 year ago, when I was still working.
I upgraded to 16 GB RAM, but only because I now go to university and know that I won't be able to upgrade for some time (read: probably at least 4 years).
For now, I use 8 GB as a RAM-disk. The other 8 are windows managed.
All runs really fast and I don't have to fear the next few generations of OS' or games (at least concerning RAM).