Author Topic: Why Is Debian Slow? (Read 12270 times)

Capn_Fish · « **on:** May 11, 2008, 10:09:37 pm »

First off, this is an honest question, NOT an attempt to start a flame war. I REALLY want to like Debian on my Zaurus.

What makes Debian so much slower than Angstrom? They both run off of the HDD and they both use EABI (?), so why the huge performance gap? Is it something I could fix?

Thanks.

PS: Is there a way to have a Debian-Angstrom dual-boot? I know at least for a while Debian was using the Angstrom kernel.

EDIT: Nevermind. I decided that my Angstrom build environment was foobared enough, as were the images, so Debian gets another chance. I'd still like to know why it's slow, though.

axeTail · « **Reply #1 on:** May 12, 2008, 07:17:46 am »

Quote from: Capn_Fish

First off, this is an honest question, NOT an attempt to start a flame war. I REALLY want to like Debian on my Zaurus.

What makes Debian so much slower than Angstrom? They both run off of the HDD and they both use EABI (?), so why the huge performance gap? Is it something I could fix?

Thanks.

PS: Is there a way to have a Debian-Angstrom dual-boot? I know at least for a while Debian was using the Angstrom kernel.

EDIT: Nevermind. I decided that my Angstrom build environment was foobared enough, as were the images, so Debian gets another chance. I'd still like to know why it's slow, though.

Hi Capn_Fish,

Are you running titchy? I've installed zdevils rootfs, with the yongguns kernel and it's fast.

Capn_Fish · « **Reply #2 on:** May 12, 2008, 12:41:34 pm »

Nope. I'm running the Yonggun kernel with the rootfs referred to above, and things take several seconds to load (even Rxvt).

EDIT: OK, maybe not several seconds, but a few.

mikeones · « **Reply #3 on:** May 12, 2008, 12:50:31 pm »

Quote from: Capn_Fish

Nope. I'm running the Yonggun kernel with the rootfs referred to above, and things take several seconds to load (even Rxvt).

EDIT: OK, maybe not several seconds, but a few.

Speed is the same here. I figured it was normal on the arm arch.

matthis · « **Reply #4 on:** May 12, 2008, 07:59:49 pm »

I am running debian from the internal microdrive on my sl-c3200. I thought the delays were due to the fact that the microdrive is slow...

Capn_Fish · « **Reply #5 on:** May 12, 2008, 10:57:12 pm »

Angstrom runs from the MD, and it is much faster.

JohnX · « **Reply #6 on:** May 13, 2008, 04:49:15 am »

A couple differences I can think of (off the top of my head) that might affect this:
-CPU specific gcc optimizations in Angstrom vs standard lowest common denominator Armv4t optimizations in Debian
-Angstrom often builds things without options that aren't typically used on a handheld, where Debian typically includes all options
-Lots of fine tuning to reduce memory usage, such as reducing the number of services run by default
-ash/busybox vs bash/coreutils

Overall, this is why for day-to-day stuff I boot angstrom from SD and for when I *need* something from Debian I boot it from a usb-stick.

Capn_Fish · « **Reply #7 on:** May 13, 2008, 07:43:47 am »

Ahh, that would make sense.

Capn_Fish · « **Reply #8 on:** May 13, 2008, 09:16:20 pm »

How hard is it to get a build setup to rebuild the repos (or at least a more condensed version) with armv5te optimizations? I have a comp that I could dedicate (1GHz Via C7, 250GB SATA HDD, 1GB RAM) to the build, if it meant a faster Debian (Angstrom has me ticked off ATM ).

judecn · « **Reply #9 on:** May 14, 2008, 02:27:22 am »

The SD card reader on the C-series is a serious bottleneck in my experience. The internal flash is faster, giving Angstrom et. al. the appearance of being faster. Also, with Debian, programs are bigger (as mentioned above, they are more featureful), so loading/unloading data from storage will naturally take longer anyway. However, in my experience, EABI programs in Debian run about as fast as their Angstrom counterparts once loaded into RAM.

If you are using a GUI, by far the biggest bottleneck with responsiveness is anti-aliasing. If you can turn it off (if your GUI even supports it), you will notice a HUGE speed boost. In fact, with XFCE on my Debian zaurus, the difference in speed before and after is about an order of magnitude.

Capn_Fish · « **Reply #10 on:** May 14, 2008, 07:56:41 am »

Angstrom runs from the MD on Spitz.

JohnX · « **Reply #11 on:** May 14, 2008, 08:41:52 am »

Cross compiling will be harder than native compiling. Someone apparently did ubuntu builds specifically targetting different ARM processors ( mojo.handhelds.org ), but they used a build farm of ARM machines, IIRC and/or qemu-arm-system on x86 machines. qemu is an option for you, but you'll probably end up with slower compiles than on a real zaurus. That being said, profiling certain programs and/or libraries and recompiling them with fewer options or CPU optimizations might make a big difference in some cases.

domi007 · « **Reply #12 on:** June 19, 2008, 02:54:17 pm »

You can try crosstool.
It can download all the things you need for cross-compile. It has a specific script for intel-xscale processors.

DOMy

Capn_Fish · « **Reply #13 on:** June 19, 2008, 06:14:37 pm »

I will have to look into that. Thanks much!

radiochickenwax · « **Reply #14 on:** June 21, 2008, 10:02:46 pm »

Quote from: domi007

You can try crosstool.
It can download all the things you need for cross-compile. It has a specific script for intel-xscale processors.

DOMy

Any pointers to a zaurus/cross-tool "how to"?

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Author Topic: Why Is Debian Slow? (Read 12270 times)