Tilted Forum Project Discussion Community - View Single Post - Is there a physically memory limit in XP?

bendsley · 10-04-2004, 06:16 AM

Actually, its not the OS that really controls the ram as it is the 32-bit addressing on processors. A 32-bit processor can handle up to 4gb of ram.

XP will only handle so much of the ram, because thats what Microsoft wants it to do. I believe the max limit XP allows you to allocate is 4gb of ram per processor. But then how many dual processor machines do you know of that have 8gb of ram in them that run Windows XP? It's very uncommon.

Microsoft has their OS limit the amount of ram accessible so that you would have to pay to upgrade the OS to allow for what you want. Example: We are running Exchange Standard on a machine and the standard version will only allow up to 16gb mail store. Well, if it goes over the 16gb limit, the Exchange Mail volume basically just un-mounts itself until you get your thumb out of your ass to fix it and get it below 16gb. Note, this is 16gb after it's passed through our spam filter (ouch). So, we had to end up upgrading to the Exchange Enterprise edition to have unlimited mail store space.

I guess I'm trying to say that the OS is the second factor in how much ram you can address, but the 32-bit processor is your first obstacle.

64-bit will be able to address 18.446 Petabytes of RAM (I hope I calculated correctly, it´s 2^64).

Since most motherboards do only support three slots with up to one GB of RAM each, 64 bit is rather a marketing trick at the moment, just like Intel with its rising GHz power.

10-04-2004, 06:16 AM	#5 (permalink)
bendsley Professional Loafer Location: texas	Actually, its not the OS that really controls the ram as it is the 32-bit addressing on processors. A 32-bit processor can handle up to 4gb of ram. XP will only handle so much of the ram, because thats what Microsoft wants it to do. I believe the max limit XP allows you to allocate is 4gb of ram per processor. But then how many dual processor machines do you know of that have 8gb of ram in them that run Windows XP? It's very uncommon. Microsoft has their OS limit the amount of ram accessible so that you would have to pay to upgrade the OS to allow for what you want. Example: We are running Exchange Standard on a machine and the standard version will only allow up to 16gb mail store. Well, if it goes over the 16gb limit, the Exchange Mail volume basically just un-mounts itself until you get your thumb out of your ass to fix it and get it below 16gb. Note, this is 16gb after it's passed through our spam filter (ouch). So, we had to end up upgrading to the Exchange Enterprise edition to have unlimited mail store space. I guess I'm trying to say that the OS is the second factor in how much ram you can address, but the 32-bit processor is your first obstacle. 64-bit will be able to address 18.446 Petabytes of RAM (I hope I calculated correctly, it´s 2^64). Since most motherboards do only support three slots with up to one GB of RAM each, 64 bit is rather a marketing trick at the moment, just like Intel with its rising GHz power. __________________ "You hear the one about the fella who died, went to the pearly gates? St. Peter let him in. Sees a guy in a suit making a closing argument. Says, "Who's that?" St. Peter says, "Oh, that's God. Thinks he's Denny Crane."