RAM question

[Husse]

This is what happens in ALL 32 bit operating systems
You can address 4 GB but about one GB of the addresses a re reserved for the hardware, like the pci bus
So it's perfectly normal

[Husse]

Thanks Husse,

So is there even a difference in having 3 gigs in and 4 gigs. ?

Troy

No - only the cost

[Husse]

Now you are talking hardware - some AMD cpus (and perhaps Intel too) use a technique (and I don't remember the name) where memory is run in parallell - if you enable that (and I think you have to enable it in BIOS) you have faster 3 GB using 4 GB (if it supports four modules) and with current memory prizes, memory is almost free of charge now...
I was only answering from an amount of memory perspective.....

[cmost]

If you want all 4GB of RAM to be recognized in a 32 Bit edition of Linux, then all you will need to do is recompile your kernel with 64 GB support. Some distribution have that option already enabled in their stock 32 Bit Kernel (Ubuntu 8.04 purports to support this option as does Parsix GNU/Linux,) others will have such a kernel available in their repositories as an alternative to the stock kernel (Debian is one distribution I can think of off the top of my head that offers myriad of different kernels in its repos.) Since Mint 5.0 is based on Ubuntu Hardy, its kernel should have the 4 GB support so I would do what others have suggested and check your hardware and BIOS to ensure you've enabled the proper options to support the full 4 GB. Regardless, compiling a custom kernel has many benefits as it allows you to optimize the kernel for your specific CPU make and model, remove unneeded hardware support (i.e, streamline the kernel,) incorporate custom or experimental patches, and add support for esoteric devices. Personally, I find it relatively simple to change the memory support to 64 GB and choose my particular make and model CPU; leaving everything else alone. The screenshot below shows my 32 Bit Parsix/Debian distribution accessing the full 4 GB of RAM in my system. I recompiled my kernel to optimize for my AMD K8 dual core processor (64 GB RAM support is already enabled in the default Parsix kernel. Performance improved noticeably with the processor optimization! If there is interest in this, then I will post a tutorial, otherwise I'll leave those adventuresome individuals to Google to figure out how to do it. My tutorials have been mostly ignored on these forums in the past so I'm not going to the trouble if there's no interest.

[Fred]

cmost,

Personally, I think a detailed how-to for configuring, compiling, and installing a new kernel would be a good addition to the wiki or the forum.

I know it will be a lot of work but I do believe there are many others that could benefit from it.

Fred

[Andy Mack]

I second that, great if such a tutorial was here.

[rivenought]

Would compiling a custom kernel in Linux Mint increase the likelihood of breakage in reference to wi-fi and restricted video drivers? In my experience with openSUSE, I know kernel updates would sometimes wreak havoc with wi-fi and video. How much can one fiddle with Clem's Linux Mint kernel perfection before it gets all wonky?

My systems run fine with the generic kernel, so I am not going to be fiddling with anything. I was just posing a question for further enlightenment. It is always good to be aware of any issues which may occur. It can get exciting!

[cmost]

Rivenought makes an excellent point and it's one that bears repeating. So called "easy" or "beginner-friendly" Linux distributions such as Linux Mint, Ubuntu, and PCLinuxOS often achieve such status by taking a lot of the hard work out of configuring and maintaining the distribution. Such confounding issues as wireless modules for myriad of chip sets, proprietary video drivers, sound cards, etc., are often handled through pluggable modules that are generously supplied by the distro maintainer through the repositories, so that the user doesn't have to compile and install them themselves. The successful installation and operation of such custom modules rely on the kernel being controllable by the maintainer. recompiling the stock kernel can break compatibility with such modules and force users to compile their own modules, or seek alternative solutions. One just coming over to Linux from the dark side (e.g., Windows) may not be up to such tasks...yet! Nevertheless, there are a few advanced users who enjoy using distributions like Linux Mint because they're too busy to fiddle with making a more flexible, albeit less friendly distribution like Debian, Gentoo, or Slackware palatable for day to day use. Others might want to experiment with compiling code. I will work up a easy to understand tutorial for recompiling the kernel for Mint. I confess, I have not yet installed the new Mint 5.0 "Elyssa" as I'm awaiting it to go Gold. Hurry up Clem!!

[Husse]

Thanks cmost
Just a small addendum - regardless of the above you still can't use more than about 3 GB - what a 64 GB kernel does is some trickery with virtual addresses, something like the tools for extended memory in DOS (highmem) if you ever encountered them. So you can address a large address space, but not use more than 3 or 4 GB at the same time. I write 3 or 4 since I don't know how this affects the hardware addresses that use up the last GB. Perhaps cmost knows - and honestly I'm too tired to google it up, been a really hot day here (for us northeners )

[jag1182]

I would like a tutorial - even aside from the issue of whether it does or doesn't allow me to really address more than 3G of RAM, it sounds like being able to set it for the various MBs I use would make it a worthwhile study.

Thanks,

Jay