KDE 4 Uses 40% Less Memory Than 3 Despite Eye-Candy

An anonymous reader writes "Pro-Linux reports that KDE 4, scheduled to be released in January 2008, consumes almost 40% less memory than KDE 3.5, despite the fact that version 4 of the Free and Open Source desktop system includes a composited window manager and a revamped menu and applet interface. KDE developer Will Stephenson showcased KDE 4's 3D eye-candy on a 256Mb laptop with 1Ghz CPU and run-of-the-mill integrated graphics, pointing out that mini-optimizations haven't even yet been started." Update: 12/14 22:40 GMT by Z : Or, not so much. An anonymous reader writes "The author of the original KDE 3.5 vs KDE 4.0 memory comparison has come out with a more accurate benchmark. In reality, KDE 4.0 uses 110 MB more memory than KDE 3.5.8.

Comments

Well

[markov_chain]

The laptop was recent, but he limited the memory use and throttled down the CPU to 1GHz. So it still had fancy instructions and a much bigger cache, bus, etc.

Re:Well

[JonLatane]

1. There's no need for Compiz on KDE4; KWin supports composited window management built-in, and that's what he was using.
2. The computer has Intel integrated graphics, you don't get much lower than that.

Re:less memory!

[Anonymous Coward]

The "unused" RAM won't be nice and empty. It'll be used as the system cache to store file data etc. that then can be accessed very quickly. Modern operating systems do not waste RAM by leaving it unused.

Re:To compare with GNOME...

[Elladan]

Keep in mind that even basic modern graphics wastes more memory than that. That background image you have on your 1600x1200 desktop? 5.4 megs. Need a few composite buffers? 5.4 megs each.

Don't have a background? Just the frame buffer to activate that graphics mode itself is 5.4 megs, regardless of what you put on it.

Just to keep things in perspective here. That Commodore 64 you had ran nicely in 64k of ram, but it also only had 320x200 graphics (160x200 in 4-color mode). :-)

Re:setup

[pherthyl]

I did in fact use the setup I described... and you can check that imacs were sold with 32 megs on wikipedia. Please check your facts before calling me a lier.

Sorry but you are completely full of shit. OS X does not run for any reasonable definition of "run" on 32mb of RAM.

Have a look at the minimum requirements for OS X 10.1 which you say was the most efficient OS X.

http://en.wikipedia.org/wiki/Mac_OS_X_v10.1#System_Requirements

Notably: RAM required 128 megabytes

And you're saying you did OpenGL development on a quarter of the minimum requirements. Riiight.

Troll. Nice one though. The moderators believed you at least.

Results are completely false

[Anonymous Coward]

Has no one pointed out that the numbers are actually completely, utterly wrong? See Lubos and Thiagos (two high-ranking KDE and Qt devs) comments here:

http://www.kdedevelopers.org/node/3138

See the original authors retraction, here:

http://www.jarzebski.pl/read/kde-3-5-vs-4-0-round-two.so

In similar conditions KDE 3 consumed 97 MB on memory, whereas KDE 4 about 170 MB.

So really, it should be "KDE4 uses 75% more memory", which is actually incredibly lame, but doesn't make for as good a title. I'm absolutely amazed that usually cynical slashdot readers have accepted this so uncritically.

Re:Results are completely false

[Anonymous Coward]

Aaargh - it get's worse. In the new analysis, he doesn't even include X-server pixmap usage, which Qt4 abuses more than Qt3: in Qt4, all widgets are double-buffered by default, and since the majority of apps are basically windows that are almost 95% covered in widgets, this adds up, fast - a kwrite window, maximised on a 1600x1200, 24-bit screen will gobble up a whopping 6MB almost, just in double-buffering. When you take into account the fact that composite then redundantly double-buffers the entire window *again* (12MB per window, now!), it just gets even worse! So KDE4 is likely using more than twice as much RAM as KDE3, yet the headline reads "KDE4 uses 40% less memory than KDE3" and is tagged "amazing" - what a clusterfuck!

And since people have short-memories, when they do discover that KDE4 takes up hugely more memory than KDE3, they'll remember "KDE developers said it used less, not much more - liars!" rather than "Someone not affiliated with KDE published incorrect benchmarks and we didn't take time to verify them". As if the KDE guys need more abuse hurled at them :/

Re:To compare with GNOME...

[EsbenMoseHansen]

I like the top bar and separate window bar at the bottom. That is very easy to setup yourself in KDE, if you please, Just right-click the panel, add an extra panel and move the stuff you need around. Personally, I think one taskbar wastes too much screen space, so mine is hidden by default. I have yet to find anything to use a 2nd for :)