Objective
Measurements
Using a gigabit
to gigabit setup, I first tested a single pair of ports for maximum throughput.
Technically, a 10/100 switch should be able to achieve 100Mbps (12.5MB/s
<= note the difference). In the real world losses, sometimes in the form
of "overhead" occur and the peak bandwidth is reduced by a percentage.
The key is to buy a product that performs at the highest level possible and
to that end, the DS2216 had the highest throughput tested to date. I consistently
measured 10MB/s (80Mbps).
4-Port
Trunking Test
The test
setup for this relatively huge undertaking involved 8 Pentium 4's with 10/100
NIC's and IBM 120GXP series 7200 rpm hard drives. Four boxes were connected
to switch "A" and the remaining four were connected to switch "B."
Next, a 115MB .cab file was located to simulate a large high speed transfer.
At the precise moment, with the help of fellow TEC
staffer Annette Kaple, we did a copy and paste that transferred the data from
switch A to switch B.
We watched
the file transfer meters spool up and sure enough an average of 7-8MB/s (NIC
limited, not switch limited) per pair was noted. This adds up to 28-32MB/s,
which calculates to 224-256Mbps. This is well above the typical 100Mbps (realistically
64-80Mbps experienced in most single switch port-to-port transfers. Based
on this test and the aforementioned gigabit port-to-port transfer of 80Mbps,
I would have no problem stating that a pair of DS2216's can saturate at 320Mbps.
Remember that this is in one direction only. Technically full duplex would
imply that 640Mbps would be 100% saturation in both directions.
Conclusion
Purchasing
two DS2216's is certainly a cost effective option to full gigabit switches.
One particular DLink model I'm eyeballing at the moment still sells for many
times the price of a pair of Compex's and the DLink only has 8 ports total!
Yes, a full gigabit solution is preferable, but is also so costly that many
small firms (or small colleges) will balk at the price. The DS2216 being "upgradeable"
as it is offers a tempting alternative to expensive gigabit over copper solutions.
If this type of networking device meets your upgrade needs then run out and
grab a few pairs. The time savings expressed in shorter file transfers will
be your reward.
William
Yaple
11/24/02
