Subject: [E3-hacking] Mass storage on the E3

From: David Given <[email-masked]>
Date: Tue, 21 Mar 2006 18:28:39 +0000

Say I want to do something real using the E3. The hardware's certainly
up to it, and the form factor is great, but as soon as I start doing
anything using serious software (such as Debian), I'm going to run out
of RAM. So, I'm going to need swap space.

Are there any alternatives to plugging in a USB1 hard disk, sharing the
single port with all my other devices?

While I have, in the past, used Sun workstations that swapped over a
10Mbps ethernet cable with roughly similar bandwidth to that USB port,
it wasn't a pleasant experience. It would be really nice to be able to
get hold of some higher-bandwidth conduit. Even just being able to
dedicate a complete USB1 port rather than having to share would be an
improvement; the boot logs say that there are three ports --- are any of
them brought out to headers on the motherboard?

Failing that, any other suggestions?

- --
+- David Given --McQ-+
|  [email-masked]    | "Those that repeat truisms, are also forced to
| ([email-masked]) | repeat them." --- Anonymous from Slashdot
+- www.cowlark.com --+

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From: [email-masked]
Date: Tue, 21 Mar 2006 19:36:20 +0000 (GMT)

> Failing that, any other suggestions?

Learn to build distributions appropriate to the hardware available? 
There's no earthly reason that anything the 5910 is capable of should need 
more RAM than you have available.  If you want to run GNOME or something 
on it, you're going to have a horrible shock when you find out how badly 
it runs X11, never mind the other stuff that's involved.

-J.

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From: Matthew Garrett <[email-masked]>
Date: Tue, 21 Mar 2006 19:59:38 +0000

> it runs X11, never mind the other stuff that's involved.

While I'd agree that the hardware isn't really up to running GNOME, 
there's omap hardware out there that's running X11 on unaccelerated 
framebuffers without too much misery. What's the issue with it on the 
E3?

-- 
Matthew Garrett | [email-masked]

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From: [email-masked]
Date: Tue, 21 Mar 2006 20:07:47 +0000 (GMT)

> framebuffers without too much misery. What's the issue with it on the

OMAPs pre-OMAP2420 suck at X font rendering, universally, though I agree 
that on small screens they're not quite as bad.  As for the E3, the very 
slow screen makes mouse pointers really, really unpleasant to use.

Also, X uses far too much RAM, and X applications tend to use too much 
floating point maths (ie., any at all) for the 925 to perform adequately. 
On top of that, there's the appalling memcpy() performance of ARM9 cores 
to consider.

-J.

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From: Matthew Garrett <[email-masked]>
Date: Tue, 21 Mar 2006 20:20:17 +0000

> slow screen makes mouse pointers really, really unpleasant to use.

Right, the quality of the screen is a serious problem. Nokia have 
managed to run X respectably on the 770, which is based on the 1710 - 
admittedly it's got twice as much RAM and a few more MHz than the E3, 
but still.

> On top of that, there's the appalling memcpy() performance of ARM9 cores 

I've happily run X on ARM9 devices with 32MB of RAM in the past, but 
it's certainly not something that I'd expect a generic distribution to 
be good at.

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From: [email-masked]
Date: Tue, 21 Mar 2006 20:22:59 +0000 (GMT)

> admittedly it's got twice as much RAM and a few more MHz than the E3,

And a better cache, and the memory bus is twice as fast, and it has a 
burst doubler so it gets about three times the memory bandwidth, and 
Harvard TLBs (which makes a huge difference under Linux.)

-J.

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From: David Given <[email-masked]>
Date: Tue, 21 Mar 2006 20:47:33 +0000

[email-masked] wrote:
[...]
> There's no earthly reason that anything the 5910 is capable of should
> need more RAM than you have available.  If you want to run GNOME or
> something on it, you're going to have a horrible shock when you find out
> how badly it runs X11, never mind the other stuff that's involved.

Aside from the fact that the E3 has more memory than the first machine I
ran X on, I'm quite aware of its limitations. I don't want to run X. What I
*do* want to do is to run headless Debian; building a distribution is a
significantly bigger and more complex job than is really worth doing, and
using a known good distribution that runs on the ARM will save vast, vast
quantities of grief.

However, as soon as you start using server software you start running into
issues where you can't put fixed bounds on the amount of memory your system
will use. While *most* of the time that 32MB will be ample, *occasionally*
memory usage will peak at larger values than that. (apt itself, for
example, tends to chew large quantities of RAM for just a few seconds on
startup.) I don't want to run using swap, but I do need to have it
available just in case --- have you ever seen Linux run out of hard memory?
It's really not pretty.

If you take a look at miniature ARM distributions such as Familiar, you'll
see that even they recommend a IBM microdrive to swap onto, for exactly
these reasons --- but the E3 doesn't have a PCMCIA slot.

-- 
+- David Given --McQ-+ "If you're up against someone more intelligent
|  [email-masked]    | than you are, do something insane and let him think
| ([email-masked]) | himself to death." --- Pyanfar Chanur
+- www.cowlark.com --+

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From: [email-masked]
Date: Tue, 21 Mar 2006 21:33:09 +0000 (GMT)

On Tue, 21 Mar 2006, David Given wrote:

> ran X on

Oh really.  Yeah, X11 has changed a bit since I ran it on a 2Mbyte machine 
with a 30MHz processor.

, I'm quite aware of its limitations. I don't want to run X. What I
> using a known good distribution that runs on the ARM will save vast, vast

No, it won't, because, and this is the important part, it won't fit into 
the only fast backing store you have available.  Trust me-  I've built 
more ARM-based appliances than you can shake a stick at, and I've used a 
tiny distribution every time.  And, yes-  I did run server software.  I 
even ran a java VM on one particular (8Mbyte!) platform.  You just need to 
make sure the server software is appropriate to the hardware-  saying "oh 
well I just need to use some swap" isn't the answer.  Your project will 
not end happily.

-J.

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From: Scot McSweeney-Roberts <[email-masked]>
Date: Wed, 22 Mar 2006 10:45:47 +0000

[email-masked] wrote:

>
>
> OMAPs pre-OMAP2420 suck at X font rendering, universally, though I 
> agree that on small screens they're not quite as bad.  As for the E3, 
> the very slow screen makes mouse pointers really, really unpleasant to 
> use.

But do you really need a mouse? If you tailor the applications and 
window manager for keyboard use then sucky mouse pointer performance 
shouldn't matter. If an app has been written with accessibility in mind, 
then it should already be usable with just a keyboard.

> floating point maths (ie., any at all) for the 925 to perform 
> adequately. On top of that, there's the appalling memcpy() performance 
> of ARM9 cores to consider.

But X gives you networking, so you can run the apps on something with a 
lot more power and access them via the E3. If you don't mind the E3 no 
longer being a stand alone machine then the networking potential of X 
brings a lot of possibilities.

Scot

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From: Jasmine Strong <[email-masked]>
Date: Wed, 22 Mar 2006 11:54:10 +0100

On 22 Mar 2006, at 11:45, Scot McSweeney-Roberts wrote:
>
> But X gives you networking, so you can run the apps on something  
> with a lot more power and access them via the E3. If you don't mind  
> the E3 no longer being a stand alone machine then the networking  
> potential of X brings a lot of possibilities.

If that's what you're after, NX or VNC would be far more appropriate.

-J.

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From: Scot McSweeney-Roberts <[email-masked]>
Date: Wed, 22 Mar 2006 12:08:46 +0000

> If that's what you're after, NX or VNC would be far more appropriate.

But NX sits on top of X, ie the client needs a local X Server. I suppose 
you could write a direct to framebuffer NX client, but then you'd have 
effectively written an X Server with the compressed X tricks of NX built in.

VNC is (usually) "all or nothing" - the entire desktop would be served 
from the server, with X you can pick and choose what runs where (so you 
can still have local X apps if appropriate). While VNC can allegedly be 
bashed into serving just applications, I've never seen this done (I've 
only ever seen it listed as a suggestion for future improvement to VNC 
servers and clients).

Scot

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From: Don Alexander <[email-masked]>
Date: Wed, 22 Mar 2006 16:01:20 +0000

> only ever seen it listed as a suggestion for future improvement to VNC

Umm maybe I am just being a bit naive about all this but is there any
reason one cannot use Nano-X (http://www.microwindows.org/) seems to
work of other platforms?

Just a thought.

Don.