Bottleneck

I'm using a Linux box with a Pentium MMX 166 Mhz processor as the
gateway router for my home network. I had a 1.5 Mb ADSL connection,
which I've just upgraded to a max 8.0 Mb connection. The speed that I
actually get depends on the distance from the exchange and the
capabilties of my modem.

I'm wondering what the slowest link is. What kind of throughput can
I expect from the Linux box?

Dan

On Thu, 03 Feb 2005 16:41:08 +0800, Dan wrote:
>
>
> I'm using a Linux box with a Pentium MMX 166 Mhz processor as the
> gateway router for my home network. I had a 1.5 Mb ADSL connection,
> which I've just upgraded to a max 8.0 Mb connection. The speed that I
> actually get depends on the distance from the exchange and the
> capabilties of my modem.
>
> I'm wondering what the slowest link is. What kind of throughput can
> I expect from the Linux box?

Assuming you're using 10/100Mbit (or better) PCI network cards
of good quality (in particular not Realtek chipset), significantly
more than 8Mbit. ISA cards and 10Mbit PCI has a theoretical max
of 10Mbit but they're not going to provide quite that much. And
with two ISA cards you'll run into the ISA bus bandwith.

Bjørn
--
Bjørn Tore Sund "When in fear, and when in doubt;
(E-Mail Removed) Run in circles, scream and shout!"
Interaction! - Anonymous
http://www.interaction.worldcon.org.uk/

Dan wrote:

>
>
> I'm using a Linux box with a Pentium MMX 166 Mhz processor as the
> gateway router for my home network. I had a 1.5 Mb ADSL connection,
> which I've just upgraded to a max 8.0 Mb connection. The speed that I
> actually get depends on the distance from the exchange and the
> capabilties of my modem.
>
> I'm wondering what the slowest link is. What kind of throughput can
> I expect from the Linux box?

Your computer is capable of far greater throughput than any ADSL or cable
modem.

As pointed out it depends on your PCI card.
Any good qualitiy card which support 100mbps is just great.

On Thu, 03 Feb 2005 16:41:08 +0800, Dan
<(E-Mail Removed)> wrote:


Thanks to all for the replies.

The NICs are only one link in the chain, and both are 100 Mbit, so
there should be no problem.

All of the packets passing through are processed and directed by the
kernel. I'm curious as to what a 166 Mz Pentium would be capable of
processing. I've done some download tests and seem to get near the
top speed. I've noticed that it tends to slow down part way into
large files, but it's hard to say what's causing this.

Dan

In article <(E-Mail Removed)>,
(E-Mail Removed) says...
> On Thu, 03 Feb 2005 16:41:08 +0800, Dan
> <(E-Mail Removed)> wrote:
>
>
> Thanks to all for the replies.
>
> The NICs are only one link in the chain, and both are 100 Mbit, so
> there should be no problem.

There is probably no NIC on the market that can't keep up with an
8mbit feed. Come on.

> All of the packets passing through are processed and directed by the
> kernel. I'm curious as to what a 166 Mz Pentium would be capable of
> processing. I've done some download tests and seem to get near the
> top speed.

If you want to know what your machine is capable of, run two systems
on your local network at 100mbit link. Run something like ttcp,
there are a bunch of choices there. See what you get. If your
machine isn't the bottleneck, you'll get better than 8mbit, probably
far better. Otherwise, your upgrade isn't goint to be so exciting.

Bear in mind that for the price of a few months' high-speed broadband
access you can have a brand new "starter PC" with a processor orders
of magnitude faster, with more memory, bigger harddrive, and gigabit
ethernet on the motherboard.

> I've noticed that it tends to slow down part way into
> large files, but it's hard to say what's causing this.

That depends on the site you are downloading from too. Try something
like dslreports.com and see what you get there, but do it about 3am
in the morning (US time) for best results.

--
Randy Howard (2reply remove FOOBAR)
"Making it hard to do stupid things often makes it hard
to do smart ones too." -- Andrew Koenig