How much memory can i use under 64-bit OS on my config?

fortytwo

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I am thinking about installing a 64-bit OS, but have one final question regarding this: how much RAM can my current config support under a 64-bit OS?

Processor: Intel Dual Core 930 (2 X 3ghz, 800 speed bus) - i checked the compatibility tool and this processor is 64-bit capable
Motherboard: Gigabyte GA-8I945P-G-RH - 945P chipset
2 GB RAM

the memory section of the MB homepage specifies RAm limits as follows:
1. 4 DDR II DIMM memory slots (supports up to 4GB memory)
2. Supports 1.8V DDR II DIMM
3. Supports dual channel DDR II 667/533/400 DIMM

I want to install a Video card with 2GB onboard memory...

My questions:
1) So, in a 64-bit OS, does the above mean that i can install a maximum of 4GB ram and the 2GB video card and get full usage of all of it? (i suppose so but would like confirmation)
2) Since a 64-bit OS is supposed to be able to use a lot more RAM, can i put in more than 4GB or am I limited to 4GB by the motherboard's RAM limit?

Thanks in advance, I'm really looking for a reply to this before going ahead with my purchase of a 64-bit OS...

 
Solution
4 gb is your limit with the current board. If you want to use more memory, you need to change to another board that is the same format as your case can handle. Many oem systems come with micro atx boards, so you would need a different micro atx board with 4 memory slots to use 8 gb of memory. But normally, 4 gb is plenty. If you want to continue to use your current board and memory, get a 2x2 gb memory kit up to pc 6400 speed, which will run at the slower limit of your board, which is pc5300. Fry's.com had some for about $20 after rebate.
4 gb is your limit with the current board. If you want to use more memory, you need to change to another board that is the same format as your case can handle. Many oem systems come with micro atx boards, so you would need a different micro atx board with 4 memory slots to use 8 gb of memory. But normally, 4 gb is plenty. If you want to continue to use your current board and memory, get a 2x2 gb memory kit up to pc 6400 speed, which will run at the slower limit of your board, which is pc5300. Fry's.com had some for about $20 after rebate.
 
Solution

fortytwo

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Thought (feared) that 4gb would be the MB's limit, thanks for confirming that!

But am I correct in thinking that with 4GB RAM and 2 GB on the Video card, under windows 32 bit it would only take a 'total' of 4gb into account?
(2 Gb kernel usage, 2 Gb application usage)
and under windows 64 bit it would take both the full 4GB RAM and the full 2GB onboard mem of the video card into account? I'm a noob at this '64 bit thinking', but I want to try it out ;)

Thanks!
 

bilbat

Splendid
it's not that simple; no matter what operating system, if you've got a pair of 1G video cards, each will 'see' it's whole 1G; but that doesn't mean the whole two gig comes 'off the top' of the RAM your OS 'sees';I have a pair of half-gigs, I map one 128K block, two 64K blocks, and two 256M blocks that are also mapped to the northbridge's PCIe controller - that's where the CPU 'talks' to the video cards - so I lose a tiny bit more than a half-gig to have a gig of video ram; my guess would be, that two 1G cards would have similar mapping, as I don't think the shared 'apperture' would be any bigger...
 

jivdis1x

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+1

Mobo support 4GB RAM then that is it 4GB. The video card memory has nothing to do with it. If it's 32bit then the 2GB video memory will eat into the 4GB memory limit set by the 32bit OS. You can have 4GB physical memory installed but only can use less than 2GB in windows.