Tech Support > Computers & Technology > Networking > LAN transfer rate?
LAN transfer rate?
Posted by jtsnow on February 7th, 2005


Im doing drive image backups over a 100baseT LAN using Norton Ghost from a
PC P4 w/XP to a network storage device.
Looks like the transfer rate over LAN is about 25 Megbit/s and LAN shows 25%
utilization and CPU about 50%. Drive is only being accessed about 1/3 the
time so drive is not limiting the data transfer.

This is a small home LAN with 4 PCs, a NAS and a printer attached.

Is 25 Mbit/s about the best one can reasonably expect to get on a 100 baseT?
Even at that rate, a 44 Gig backup can take a few hours.

Are there ways to easily tweek the LAN to get significant transfer rate
performance improvements? Or is 25% utilization the best I should expect
on a 100mb/s LAN?

Any tips appreciated.


Posted by Yousuf Khan on February 8th, 2005


jtsnow wrote:
I've seen my own transfers top out at 12.5%, while I've seen some
servers transferring at upto 60% efficiency. I don't what causes it, it
could be driver efficiency or perhaps some ethernet chipsets have more
intelligence.

Yousuf Khan

Posted by Bob Willard on February 8th, 2005


Yousuf Khan wrote:
25% is poor and 12.5% is pretty terrible. I just tried copying a large
(~1GB) file between a couple of XP PCs over a 100 Mb/s FDX net (with a
Linksys BEFW11S4 switch in the middle), using Explorer's drag'n'drop.
NetPerSec showed ~9.9 MB/s pushing the file, and ~9.1 MB/s pulling it
back; ~79% efficiency pushing and ~73% pulling.

I confirmed those transfer rates by stopwatch+calculator. And I repeated
the experiment with a somewhat faster far-end PC, using Explorer's CTRL-C
and CTRL-V, getting slightly better transfer rates: ~9.9 MB/s pushing,
and ~9.5 MB/s pulling; ~79% pushing and ~76% pulling.

Note that file transfer STRs seem to be much better in an all-XP workgroup
than in a mixed XP-W9x workgroup; my earlier results with a ~0.5GB file
on a XP-W9x 100 Mb/s FDX net were:

- Pushing on 98 from 98$ to XP$: 86 secs => 5.81 MB/s
- Pulling on 98 from XP$ to 98$: 82 secs => 6.10 MB/s
- Pulling on XP from 98$ to XP$: 159 secs => 3.14 MB/s
- Pushing on XP from XP$ to 98$: 236 secs => 2.19 MB/s

All these results were using network mapped drives.
--
Cheers, Bob

Posted by Mike Scott on February 8th, 2005


jtsnow wrote:
machines has been observed to hit throughput by an order of magnitude.
Never did find out why.

Posted by jtsnow on February 9th, 2005


ok...i can try turnig those off as an experiment

thx
"Mike Scott" <v.nin@1.scottsonline.org.uk> wrote in message
news:36s7hcF56n7o6U1@individual.net...


Posted by jtsnow on February 9th, 2005


ok...thanks...im my situtation is ethernet comin in to a external USB on the
PC. I think thats the link slowin everything down. Just ethernet to
ethernet its very very fast....its the USB in on the external drive thats
the killer....i think

"Bob Willard" <BobwBSGS@TrashThis.comcast.net> wrote in message
news:e7CdnYYHSrY0VpXfRVn-rw@comcast.com...



Similar Posts