# Max RAM for 64 bit Linux



## 22moondune

Hello all. I just upgraded the RAM in my PC to 4Gb from 2Gb and the difference is very noticeable. My motherboard states it can support up to 8Gb of RAM, so I have been considering upgrading to 8Gb. My question is this: I have the 64-bit Ubuntu Linux. From what I have heard, the 64-bit Linux distros have no max limit for RAM, but will the OS actually be able to utilize 8Gb? I appreciate your comments. :wave:


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## hal8000

22moondune said:


> Hello all. I just upgraded the RAM in my PC to 4Gb from 2Gb and the difference is very noticeable. My motherboard states it can support up to 8Gb of RAM, so I have been considering upgrading to 8Gb. My question is this: I have the 64-bit Ubuntu Linux. From what I have heard, the 64-bit Linux distros have no max limit for RAM, but will the OS actually be able to utilize 8Gb? I appreciate your comments. :wave:


A 32 bit CPU can only address 4GB of ram, thats a hardware limitation based on the number of address lines (32) availableto the CPU. With a 64bit CPU you the addressable memory is now 2^64 or 16.8 million terabytes. If you look on the Ubuntu forum you will see many people already using machines with 8GB of memory- but what you have to rememer is that not every application is written with a 64bit CPU's. In addition, memory usage depends on what functions youre running. Memory and resoucrce hungry tasks like compiling a new kernel, video editing, running multiple makes will happily eat up your ram, but youre probably not likely to notice much improvement in performance unless you perform labour intensive tasks.


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## 22moondune

Thanks a lot hal8000. That answers my question. cheers!


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