ArchiCAD 12 and RAM

[David Collins]

Djordje wrote:
Never enough memory - double it.

(Introductory quote borrowed from another thread)

Win XP has a RAM ceiling of 2 GB, I believe, while Vista will take 4 GB and use maybe 3.25 of it.

My question: Will the new multi-core processing of A12 benefit from a serious increase of RAM?

I see some Mac Pro users like Mathew with 10 GB RAM. (drool)
Given the new multi-core A12, is it time to think about switching over to the Mac side, strictly (please) from a RAM point of view?

[Chazz]

David wrote:
Win XP has a RAM ceiling of 2 GB, I believe, while Vista will take 4 GB and use maybe 3.25 of it.

You CANNOT be serious -can you? I can't imagine this is true or that it cannot be extended or easily increased. I know precious little about Windows (other than that I dread using it at the office as my backup machine. That machine, BTW, an XP box, has 3 GB loaded). If this is the case I can't imagine why anyone doing serious computational work would be using this OS.

We need Karl to weigh in....

[Karl Ottenstein]

It sounds like it is not a Windows machine limit, but a per-application limit.

See:
http://msdn.microsoft.com/en-us/library/aa366778.aspx

Easier to read is this older article:
http://www.microsoft.com/whdc/system/platform/server/PAE/PAEmem.mspx

which notes that XP Pro 32 bit can have 4 GB available, but will keep 2 GB for the OS and will allow up to 2 GB for an application. BUT, XP Pro has a /3GB 'switch' described in that article that allows an application to have 3GB available for its own use. I know that the recently released Artlantis 2 will take advantage of this /3GB switch. I do not know if AC 12 (or earlier) is set up to take advantage of this.

Just my interpretation of the above articles ... Ralph would be a better source of info on this...

Cheers,
Karl

[henrypootel]

It is indeed true that Windows XP32 can only address a maximum of 4Gb, and even if you use the /3Gb switch, you still will only ever get at 3Gb of it. If you are doing the kind of work that would require more than 2Gb of RAM, then you should be using a 64-bit OS. This means either WinXP-64, Vista-64, or OSX.
That said, there seems to be a lot of people mixing up 'multi-core' and '64-Bit'. these are 2 completely different things. 64-bit versus 32-bit is merely a matter of how the machine address the memory available to it. the only performance gains to be had from a 64-bit system will be those gained by having more RAM.
Multi-core on the other hand refers to how many physical CPUs the machine has. Application need to be specially written and compiled to make use of multiple cores, and will almost always result in a significant speed boost becuase there are 2(or more) cpus doing the same amount of work that was previously being done by just one.
There will not be any speed difference between a multiple-core application running on a 32-bit OS and one running in a 64-bit OS, except when the application runs out of RAM. at this time, the 64-bit machine will be able to use more RAM, and so will become faster.

[David Collins]

Thanks for the information. A lot of my technical support comes in a foreign language, so I'm never completely sure what I'm hearing. As if it wasn't all in a foreign language to begin with....

[Anonymous]

Just wondering about Cached Physical Memory. I have 8 gigs of RAM on my machine, and the Cached amount reads 5600 (MB) fairly constantly. Does that mean there is 5.6 gigs of RAM thats just sitting there unused? If so, can I change settings to allow Archicad to use it?