Re: raptor or cache?



On Sun, 15 Jan 2006 12:07:24 -0800, ivowel wrote:

>
> I want to build a fast linux machine now. Among my choices are whether
> to put more money into memory ($70/GB), or more money into a Raptor HD
> RAID-0. I believe linux uses a cache write-back scheme, which is good
> for me. I do not like the idea of data sitting for hours on an
> external hard drive, but data that is written to "when convenient,"
> where convenient is a number in the low minutes. Still, I understand
> that battery-backed RAM drives on PCI-E cards are on the horizon. I
> guess I could set up an automatic rsync.
>
> Now, realistically, almost all my linux operating system fits into 1GB.
> All of my user files that I am working on on any given day would fit
> into another 1GB. I pretty much know where the these preferred areas
> are. Alas, what would be useful in such a situation would be the
> ability to designate some files or directory areas as "preferred to
> retain in cache", others as "normal cache", and others as "do not
> cache". for example, under gentoo, I do not want my 6GB /usr/portage
> tree to be cached. and, given the choice between discarding a
> preferred and normal buffer, I would like the algorithm to prefer to
> dump the normal cache.
>
> Possible?
>
> sincerely,
>
> /iaw

Generally more memory helps a lot more then a faster drive. A 10000 RPM
disk is only useful if you are accessing a lot of small files and you
aren't ever accessing them again. Linux uses the available RAM to cache
files so as long as you have enough RAM you'll hardly ever do a disk
access. In my experience 2G is sufficient for a desktop system. You can
live with 1G but at 2G you never page out your file cache. Above 2G is
useful only if you have some application that uses a huge amount of RAM.

.



Relevant Pages

  • Re: How to set up a Linux machine that occupies the minimum memory footprint ?
    ... Of course, if you use 8GB of RAM, or more precisely if you ... Are you saying that if I have a 4GB RAM memory, ... Linux will somehow "know" that it doesn't have ... You've said in another message that your app is ...
    (comp.os.linux.setup)
  • Re: How to set up a Linux machine that occupies the minimum memory footprint ?
    ... Of course, if you use 8GB of RAM, or more precisely if you ... Are you saying that if I have a 4GB RAM memory, ... Linux will somehow "know" that it doesn't have ... You've said in another message that your app is ...
    (comp.os.linux.misc)
  • Re: OT (slightly) swap limits
    ... influence your decision on how much swap was enough. ... processes due to lack of memory. ... I've run machines with 1Gig or more RAM with NO SWAP. ... Linux possible when before on Unix it wasn't? ...
    (Debian-User)
  • Re: Available RAM - Lying sack of SHIT
    ... 4GB RAM installed but I am told Vista can only manage 3GB RAM. ... If you use Linux then your programs won't ... Your WINDOWS programs, slick. ... Last week you said that you knew how I spent my money. ...
    (microsoft.public.windows.vista.general)
  • Re: Available RAM - Lying sack of SHIT
    ... 4GB RAM installed but I am told Vista can only manage 3GB RAM. ... If you use Linux then your programs won't ... Your WINDOWS programs, slick. ... Last week you said that you knew how I spent my money. ...
    (microsoft.public.windows.vista.general)