I just saw a thread that made me start thinking:

What is the bandwidth limit for:

Serial
Parallel

And is firewire/usb2 faster than 10/100 ethernet and could you connect ocmputers using those methods?

I will have to google this, but it seems that i recall firewire/usb2 to be insanely faster, and if so than it would be better to use those for clustering.

Any thoughts?

USB 1.1=~11MB/s
USB 2.0=~40MB/s
Firewire=~40MB/s
ethernet=~10MB/s
fast ethernet=~100MB/s
giga ethernet=~1,000

The problem with:
USB: All data that comes through the port has to go by the CPU
Firewire: I don't know
It is posable to network usb
-Joey

Clearly your actual best bet is to use giga ethernet if cost is nothing to you. But you can get fast ethernet out of regular old NIC's most of the time.

My own home network I can get fast ethernet out of and it's way faster than usb, etc.

Wow I thought Firewire was faster than that. I guess giga is the way to go. I think 100 would be fine but once you start hooking up 40 or so computers together then you will start really getting degraded network performance because of conflicts, even with a router.

With tcp/ip you only get about 800k of data for every 1M transmited the tcp/ip need an update

Just being picky, but I thought USB2 was 45 and just pipped in front of Firewire because of it.

But yeah, Fast Ethernet beats the pants of others. Copying stuff over USB2 or 100Mbps ehternet - I know which I would choose

<edit>
I just thought: Isn't the limit for standard PC serial ports 115k?
</edit>

64-bit gigabit ethernet cards are a good choice. you can always have >1 per system and optimize throughput over either multiple subnets or nic binding.

ethernet = 10Mb/s = 1 MB/s; i agree, ~80% efficient

fast ethernet = 100 Mb/s = 10 MB/s; ~80%

giga eth = 1000 Mb/s = 100 MB/s; i never get better that 50-60% eff here even with xover cable and custom-optimized linux drivers on 64-bit cards, not limited by HD throughput, maybe by CPU but prob not by protocol itself.

Some of these numbers are a bit jostled:

USB 1.1 is 11Megabit, so 1.2Megabyte/sec, although degradation over distance is annoying so more like 1Mb /sec.

USB 2.0 is right, but the cable's max length is about 12 feet, maybe 8.

Firewire has a number of different specs and one will do 80Mb/sec if I remember right. The cable length is a problem again too... longer then 14 and the cable will no kidding, melt! Transfer a ton of data over a firewire line and then you'll notice the cable is quite warm.

ethernet I assumed meant 10BaseT, that's 10Megabit again, about 1Mb/sec... in a segment cable up to 100m I think.

similarly divide fast and gigabit by ten and no kidding, there's a fast gigabit spec now that can actually clock in at 1000MegaBytes/sec. Good luck building something that can handle that... it would have to be RAID 10 of SCSI 320 drives.

Its possible to network both USB and firewire. For fiirewire the module is eth1394.o For USB I know you can do a machine to machine link with usbnet.o.gz

I don't know if you can hub it though, I would guess no...

Easiest way would still seem to be a gigabit card though, more distance and a full network.

Cheers,

Finegan

Those numbers bring me to a different issue:
WHY THE *(fill in your preferred expletive,verb or noun) do they make keyboards and mice on usb?
It's not like these are going to generate the "massive" amounts of dataflow , this bus is intended for , now is it?
Why waste two (one for keyboard , one for mouse) usb-ports , while leaving the perfectly working ps/2-ports idle?
Example : I have four usb-ports on my system , of which are in use:
1-scanner (HighRes-scans means cartloads of data)
2-Printer (See: Scanner , but the other way around)
3-Digital camera (As in : Scanner)
4-Reserved for either :external drive , thumbdrive , (possible)usb-DSL-modem , (maybe applicable to some)MP3player , etc.... All devices that benefit from from a "sturdy" amount of bandwith.

Then why do I have to apply a separate adapter for making my mouse capable of using the ps/2-port?
What'sthe use of USB for mouse or keyboard?
The ps/2-port already can handle way more than those two devices can come up with.

i'm pretty sure it was replacing the USB mouse with an AT mouse on 2 diff windowsXP computers that improved stability.