How do I maximize data transfer speed on my LAN?

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Fantastic. That clears up a lot of questions I had. Thanks Leo.

Leo's the man! I nominate Leo for the Nerd Hall of Fame.

A couple of quick other bits of potentially useful data:

First, just about *any* Internet connection will be slower than your internal business network and should have very little impact on a switched system. I know that the Internet wasn't included in the original question, but sharing the Internet connection seems to come up often in small network questions.

Second, if you have a wireless connection into your network, don't expect the wireless connection to operate as quickly as the wired machines. I bet Leo could dedicate a whole article to getting decent speed from wireless networking. Wireless wasn't mentioned in the original question either - but it tends to come up in small network questions too.

I have to agree with Leo about network speed. This year I upgraded my home network to gigabit and rarely see much difference from the 100 megabit switched. The other day I hit a series of files from two different machines (copying from the server to two different machines) and the *second* copy of 111 files was amazingly fast... it was sitting in the cache of the server, so there weren't any hard drive bottle necks.

Recently I moved locations at work - the original location was running at 10mbps half-duplex - the new location is running at 100mbps full-duplex. Whoosh - what a difference!

Leo: Interesting that hard disk transfer speed turned out to be the weakest link in your networking chain. How did you figure this out?

Just for the record, different parts of the hard disk transfer data at different speeds. Not that it matters though, I can't imagine how anyone could force the placement of files to a specific section of the platters.

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I started with a machine-to-machine copy, and was disappointed. :-)

So, on a hunch, I did a drive-to-drive copy on the same machine (happens to
have two drives) and the number was VERY similar.

Then I did a copy to NUL, (i.e. just a read of the entire file) and once again
the numbers were very similar.

If I recall right, I was using a CD image of around 650 megabytes.

Thanks,

Leo

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Good hunch. :-)
How do you copy a file to NUL?
I assume with a DOS command...

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Exactly. NUL is just a special filename, so:

copy filename NUL

Reads the entire file and copies it to ... NUL.

Same idea as CON (screen and keyboard), LPT1, COM1 and so on.

Leo
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Relief!! ~2x is the best we are achieving after upgrading all to 1Gb.
The rate from an internal (4+GB)to an internal was twice the rate of xfr from the internal to an external on another machine (USB connected HD).
Best rate was 10.17MB/s at 1Gb
We thought we had major problems. Thanks for the writeup. Intel was no help except for driver upgrades.

With he speed of SATA drives and the GB network, does the FSB speed (400, 800, 1333, 1600...) may also be a bottleneck?

I READ THE ARTICLE THOROUGHLY, BUT NOT SATISFIED AS MY PROBLEM IS DIFFERENT.RECENTLY I SHIFTED MY NETWORK WITH GIGA SWITCH & gaga lan cards & cat6 cable to all my pcs, but the data transfer speed is even reduced to 10mbps, not getting why it is so?

alex, no, sata hard drives have better BURST rates, up to 3gb/s but that isn't how fast the drives read, its the physically spinning disks that limit the hdd transfer rates so an upgrade to sata doesn't inherently mean a massive increase in any file reading or writing.

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