Maximum RAM

TCPMeta

I've always thought about this. Say you have a motherboard that has four slots of SDRAM that can use PC133 but you can only have 1.5GB of ram as the maximum, yet there are sticks that you can use 2GB like set of 4x512MB however the motherboard will only see 1.5GB or freak out when there is too much memory. Why is there a maximum cap off? Is it the chipset that was used at the time? I know on newer systems their really isn't much of a maximum cap and i've seen BIOS updates that add support to faster CPUs.

Just a random question while I was trying to dig up some memory for a old system.

BlueSun

It's still a problem even on modern hardware. I had an i7 machine with a cap of 24 GB. I've seen others with a cap of 32 GB.

It's my understanding that it has to do with how much memory the CPU can address. They put limits on memory address space to reduce the cost of the CPU.

calvinb

Well, some of it can be blamed on the northbridge (integrated nowadays) and artificial limitations.

BOD

The cynicist in me (that's all of me, if I'm honest), would suggest it's to make you pay for the more expensive board.

TCPMeta

I agree with BOD.

non-PAE 32bit systems can handle 4GB so if there is a memory module that is compatible I should be able to use it but since chip makers don't want to follow the standard it kinda pisses me and probably others off.

Oh well, doubt Intel and AMD even built a 386 CPU to use 64MB of RAM let alone 32MB.

TCPMeta

Check this out. The other day I was looking into on adding more memory to my macbook pro and came across that on some mid-2012 models you can upgrade the ram to 16GB depending on the OS version and Firmware updates. Apple only had them capaible of using 8GB. Sadly it only works on the mid-2012 models :(