Most lightweight distros almost completely rely on memory which should only prove costly. The lighter ones I've tried are Lubuntu and Mint, could you tell me how to measure which is lighter?

I don't know if Peppermint OS Two is one of those memory hogs, but I've read that it's lightning fast:

http://www.linuxuser.co.uk/reviews/p...os-two-review/

To answer your thread title, DSL

Lightning fast at what, boot time? program load? If internet browsing probably depends on browser used.

lightweight, and fast:

gentoo, debian, slackware

What are your hardware specs and what do you use the computer for? It is impossible to give a recommendation without that information.

Also I think you are making a flawed assumption that "the fastest distros are those that use the least amount of RAM." I'm sure if you do a "thought experiment" you can imagine a very slow distro that doesn't use much RAM, or a very fast distro that uses lots of RAM.

Personally I have had very good luck with SliTaz on my oldest hardware (500mhz Pentium 3 with 256mb RAM) but in the end I chose CrunchBang for that computer, because it is more full-featured.

Depends on what you want to use it for really. A min Slackware install uses about 40mb of ram and boots in seconds. No GUI at all though.

I think you need to be more specific in what you want the box to do in order to get the best answer possible.

In my experience Puppy Linux is the fastest lightweight distro that does everything I need, but DSL is the fastest.

DSL is quite obsolete. Kernel 2.4 and Firefox 2.0... ugh!

Here are my figures for RAM usage when idling:
Vector Light (Icewm) 40MB
Yoper (Xfce) 60
Salix (Xfce) 80
WattOS (LXDE) 90
Vector Standard (Xfce) 100
By comparison, XUbuntu and Mint Xfce took 150, but that's only half what Mandriva uses! I've ignored distros than require you to jump through a lot of hoops to get started.

Of course, there are things other than RAM usage. The number of task running was
Vector Light 63
Yoper 89
Salix 113
WattOS 112
By comparison, Mint Xfce 117 and XUbuntu 109. The villain here is again Mandriva with 141.

I think slitaz may be the least other than the qnx demo disk.

+1.

Boot time you can see from installing 'bootchart', program loading times....I tend to just use a stopwatch (LOL, yeah, I know). You can also check RAM and CPU usage, I use htop (gnome system monitor/KDE system monitor are not as 'light' as I would like)

There are always reviews aroudn saying how 'lightning fast' peppermint is. I've seen the term so many times in relation to peppermint I wonder if most of those reviews are by fanbois (or at least very, very lazy reviewers who just copy and paste from other reviews).

Peppermint probably is 'lightning fast' in comparison to a 'full' ubuntu release. Compared to other distros, ubuntu always tends to be bloated and slow, so 'lightning fast' doesnt mean much if its in comparison to ubuntu. Peppermint wont be any faster than lubuntu, and with all the extra 'cloud' programs installed it could be slower.

If you want to use it in vmare/vmplayer for development，u can try my disco smtlinux, build from lfs. No X of course

www.tinycorelinux.net

fresh.. fast.. new.. slim (not fat)

Athlon 3 GHz dual-core
3 GB RAM
250 GB HDD

No, most lightweight distros use too much RAM!

Throw another gig of RAM in there and you should be able to run Puppy Linux no problem.

Why do you want a lightweight distro and why do you want to be super careful of ram?

3GB of ram is enough for a heavy GUI full featured distro for most uses.

You answered snowpine about the hardware specs, but not about the intended uses of the system. Unless that is some very strange intended use, your hardware specs make your whole question pointless.