http://brainstorm.ubuntu.com/idea/5039/

I always thought that you needed the smp kernel to take advantage of the second
multiprocessor, but it seems that smp is built into all kernels of Ubuntu,
although I am not sure, because I only know what I read online as I am not a
hardware expert.

It definitely is in 8.04. A uname on my desktop shows 2.6.24-19 SMP;
SMP = Symmetrical Multi-Processor. A "live" CD of 8.04.1 shows the same
and my live CD of 7.10 shows 2.6.22-14 SMP.

Probably 99.999% of all apps are written single-threaded and would not
themselves benefit from a multiple-core system. However, if one starts
two apps, each will [effectively] use one core.

If one app has a bug and eats all CPU time, in a dual-core system the
other core is "free" and it's easy to kill the errant process. Multi-
core systems will soon be the norm.

Then not much reason to have a multi-core setup yet then.

I kinda think (and this is just from programmers I know and talk to now)
that multi-core apps wont catch on for the desktop as (programmers)
believe there isnt much reason to do the extra work. Kinda sucks but I
can see their point.

Well, I suppose it depends on how you value *your* time. :-)

Last week I needed to concatenate some 50 PDF files that comprised
a logical document so that it'd be easier to search one document.

Because I didn't want to bootup a Windows box to use Adobe Acrobat,
I used the free PDF Split and Merge program that's written in Java
and available here:

<http://http://www.pdfsam.org/>

There's a bug in the program such that it doesn't automatically add
".pdf" to the output file and it was stuck in a loop eating all CPU
time. On a dual-core system it was trivial and fast to kill the
process. I tried it again on a single-core system and it took about
5 minutes to bring up a terminal window, identify the process and
kill it (all using top) -- the errant program had literally taken
over the system (and a ^C or clicking the window's "Close" did nada).

The cost of computing has come down but people time is expensive.
The last two systems I bought new were both dual-core and both under
$300; one is a Pentium E2180 2GHz Core-Duo (from Fry's Electronics)
and the other is an AMD Athlon 64 X2 Dual Core Processor at 2.2 GHz
(from Office Depot). Both dual-cores, BTW, are 32-/64-bit capable.

It sees all four of my cores.

Four cores are noticeably faster than one. 64 bit and multicore aware
apps are starting to appear. Percentage is well less than 50%, but a
bit higher than the three sigma value previously posted. 1/1000 of a
percent would be 1 in 100,000 programs. Not quite that bad.

The benefits of multi-core awareness by an app depends on the app.

I'd be hard-pressed to believe that, say, "ls" or "passwd" would
benefit, but a multimedia program most assuredly would benefit, and
any programs that spawn child processes via fork() indirectly benefit
whereas those using system() will not [due to its implementation using
waitpid()].

There's no question that a multi-core system overall "feels" faster
than a single CPU system, and it's easy to test by disabling one core.
I find myself doing things on the multi-core systems that normally
I'd have to do sequentially on a single CPU system. The multi-core
systems have paid for themselves (for me) by my time saved.

I do agree with you that there are not as many 64 bit, and multicore
capable programs as there should be.

We've had 64 bit processors for how many years now? And multicore
processors are not that new. Yet 64 bit operating systems are still
not dominant, and programs still have issues with them. On my win-box
I've been using F-Secure for virus protection. When I upgraded to a
newer machine, it came with Vista 64. Guess what, F-Secure is still
not 64 bit ready. Went with Avast which is, and now I have a nasty
little virus/torjan downloader that maybe after buying yet another
program to rid the machine of malware, I might finally be rid of.
(Haven't had an alarm in over a week, but it took two weeks and
multiple deep scans to get rid of it, if indeed it is really gone.
Which is another reason why I like Linux.)

But even in the Linux world, 64 bit versions are not as reliable as
their 32 bit brethren.

Ahh... but help is on the way. According to the Science Channel,
within 10 years they expect computers to become self aware. At that
point they will be smarter than us, faster than us, and will write
their own programs and eventually decide what we need and possibly
whether we should even continue to exist. (Sure hope that self aware
machine is based on Linux. If it comes from Microsoft, be very
afraid.)

If you are running Linux as well as Windows. My question, is why are you using
the internet using Windows? Linux is far more secure than surfing with Windows.
I know people who only use Linux/Unix for Internet and Email purposes only.
Just to prevent the nasties coming in.
As for 64 bit Kernels using Windows or Linux. It is the catch up game for the
software to developed around that structure. It is like 8 bit, 16 bit, 32 bit,
and now 64 bit. It is going to take time. I use to work in the computer chip
manufacturing biz. It use to be to wait for the software companies to catch
their breath. Wait for the RD of the software to catch up before introducing the
new mouse trap. It use to be govern what software was out there.
Well, the chip makers are tired of that game. Thus making the S>W companies to
speed up. Mainly why is very simple. Servers! If you are in the internet server
biz you want the fastest processor out there to provide to your customers

Thanks for clearing that up. As you say, multicore is the new norm. I have a
question as you seem knowledgeable. Do you get any benefit to running a 64 bit
processor with single core with a 32 bit OS? I had heard that you lose lots of
processing capability except it is of benefit when running VMs as they are able
to use the unused portion to run like a dual core.

I don't notice any benefit when running my AMD 64 on a 64 bit OS versus a 32 bit
one, but I have lots of RAM and a good video card and probably don't strain it
too much such as gamers do. I also don't notice any slow down when I run
VirtualBox with Windows XP inside Ubuntu 8.04 and therefore wondered about what
I had heard about VMs and 64 bit processors. Your thoughts might clear this up
for me.

Are you running Ubuntu as a stand-alone OS, or are you running it as
an "application" inside Windows XP? If you are running it inside
Windows, and Windows is a 32 bit version, then you might not be
utilizing all 64 bits.

Host OS is Ubuntu 8.04 x86 32-bit with Windows XP SP2 running on Virtualbox. I
have an AMD 64 single core processor with 4 GBs of RAM and 512 MBs video RAM. I
have the XP VM set up with 640 MBs of RAM and 64 MBs of video exclusively for XP
and it runs fast enough for normal tasks, but I am not a gamer. It would be
faster with a multicore processor because Virtualbox allows me to tweak it for
multicore.

I am wondering if it would run faster if I ran 64-bit Ubuntu than 32-bit. I had
heard that it would run faster in 32-bit as Virtualbox sees the 64-bit as a
multicore. I am not sure if this is bogus, wishful thinking or misinformation,
hence my question.

I run 32-bit just for ease of use due to lack of 64-bit applications. I run
64-bit dsitros on other partitions and can't see that it makes any difference.