<p>Jeff covered this a while back <a href="http://www.codinghorror.com/blog/archives/000811.html" rel="nofollow noreferrer">on his blog</a> in terms of 32 bit Vista.</p>

<p>Does the same 32 bit 4 GB memory cap that applies in 32 bit Vista apply to 32 bit Ubuntu? Are there any 32 bit operating systems that have creatively solved this problem?</p>

In theory, all 32-bit OSes have that problem. You have 32 bits to do addressing.
```
```
2^32 bits / 2^10 (bits per kb) / 2^10 (kb per mb) / 2^10 (mb per gb) = 2^2 = 4gb.
```
```
Although there are some ways around it. (Look up the jump from 16-bit computing to 32-bit computing. They hit the same problem.)