2gb vs 4gb

[hitman24]

if you could have either what would you choose? it will be with a core 2 duo cpu. like would things benefit from having 4gbs?

 

[Assman]

if you got vista than 4 gigs would help, vista uses a lot of ram even when idle

 

[Mondoman]

But since you'd need the 64-bit OS version to access the 4th GB (roughly), better to upgrade to 3GB.

 

[hitman24]

so what would be best 3x1gb sticks or 1x2gb stick along with 1x1gb stick?

 

[oc]

2x1gb and 2x512mb so you can use dual channel mode.

 

[Datablitz]

prolly 2x1GB and 2x512MB so you can run them dual channel...

 

[sweetpants]

But since you'd need the 64-bit OS version to access the 4th GB (roughly), better to upgrade to 3GB.

On a system configured with 4 GB of random-access memory (RAM), Microsoft® Windows® reports 3.0 to 3.8 GB of available memory. The same behavior is seen in Linux and other operating systems, as this is a limitation of 32-bit addressing used in IA-32 systems.

This is a limitation of a 32-bit architecture. The system can only address 4 GB of allocated memory. Allocated memory is made up of physical RAM, and any I/O space needed by devices. The way memory is allocated is that starting at 4 GB, the system allocates device I/O addresses working its way down. Normally this is not a problem, but when systems have 4 GB of physical memory, the addresses needed to address RAM overlap the space needed for I/O. In this case, the need for I/O space takes precedence, and the amount of RAM visible to the operating system and applications is limited to 4 GB minus I/O space. Examples of devices that consume I/O space are:

System BIOS
PCI Express configuration space and memory for PCI Express device(s)
Memory mappy I/O
Motherboard Resources (I/OxAPIC)
Chipset
PCI Enumeration
For example: If you have 4GB of system memory, an Intel 915g Express chipset, Windows XP with Service Pack 2, and a PCI Express graphics card the remaining system memory as reported by System Information would be ~3.25GB. The same configuration but with 2GB of system memory would result in all 2GB being available. This is due to the limited capability of memory mapping (or limited amount of addresses) on 32-bit architecture systems.

I would use 4GB of memory, that way when you upgrade to vista32 or 64, you have 4GB to go along with it.

EDIT:

By default the most memory XP can assign to any task is 2GB, unless when installed with a certain switch (I forget what the switch it) that will allow a maximum of 3GB assigned to a specific task.

 

[darkstar782]

I had 3GB (3*1GB), but sometimes ran with 2GB (2*1GB) for dual channel mode.

I did notice some advantage with 3GB, Possibly because I run alot of stuff in the background. For benchmarking I'd run 2GB for dual channel.

Now? I'm running 4GB @ DDR2-1000 4-4-3-10 speeds, and it rocks!

(especially as this is only DDR2-667 rated RAM D9MGH for the win)



CPU-Z Validation

 

[Mondoman]

But since you'd need the 64-bit OS version to access the 4th GB (roughly), better to upgrade to 3GB.

On a system configured with 4 GB of random-access memory (RAM), Microsoft® Windows® reports 3.0 to 3.8 GB of available memory. The same behavior is seen in Linux and other operating systems, as this is a limitation of 32-bit addressing used in IA-32 systems.
While true for 32-bit Windows XP and 32-bit Vista, this isn't true for many of the 32-bit Windows server OSs, and apparently not for at least some 32-bit versions of Linux. These OSs make use of the hardware extensions (Physical Address Extension) found on most Intel-based (and many AMD-based) CPUs/MBs that allow for 36-bit physical memory addressing, given an OS, software, and drivers specially written to accomodate PAE.

By default the most memory XP can assign to any task is 2GB, unless when installed with a certain switch (I forget what the switch it) that will allow a maximum of 3GB assigned to a specific task.

The switch can also be specified at Windows boot time, but does require any apps that want to take advantage of the 3GB to be compiled with a matching switch.

 

[sweetpants]

But since you'd need the 64-bit OS version to access the 4th GB (roughly), better to upgrade to 3GB.

On a system configured with 4 GB of random-access memory (RAM), Microsoft® Windows® reports 3.0 to 3.8 GB of available memory. The same behavior is seen in Linux and other operating systems, as this is a limitation of 32-bit addressing used in IA-32 systems.
While true for 32-bit Windows XP and 32-bit Vista, this isn't true for many of the 32-bit Windows server OSs, and apparently not for at least some 32-bit versions of Linux. These OSs make use of the hardware extensions (Physical Address Extension) found on most Intel-based (and many AMD-based) CPUs/MBs that allow for 36-bit physical memory addressing, given an OS, software, and drivers specially written to accomodate PAE.

By default the most memory XP can assign to any task is 2GB, unless when installed with a certain switch (I forget what the switch it) that will allow a maximum of 3GB assigned to a specific task.

The switch can also be specified at Windows boot time, but does require any apps that want to take advantage of the 3GB to be compiled with a matching switch.

Ahh very cool, I wasn't aware of that!

 

[hitman24]

so if i get either 2x2gb or 4x1gb i could run them in dual channel?

 

[Mondoman]

That should work (of course, it depends on your MB's support for dual channel).