I have spoken to a Dell technician who is a friend of mine and he
specifically pointed me to this article relating to your switch.
Dell Device Port Configurations
A combo port is a single logical port with two physical connections:
* A RJ-45 connection for Twisted Pair copper cabling
* A SFP connection for various fiber-based modules
Only one of the two physical connections of a combo port may be used
at any one time. Port features and available port controls are
determined by the physical connection used.
The system automatically detects the media used on a combo port, and
utilizes this information in all operations and control interfaces.
If both RJ-45 and SFP are present, and a connector is inserted in the
SFP port, the SFP port is active, unless the copper connector of the
Base-T port of the same number is inserted and has a link.
The system can switch from the RJ-45 to the SFP (or vice-versa)
without a system reboot or reset."
It seems to me that the short answer is NO it cannot be done with your
switch using combo ports. However, you may be able to utilise
something known as "aggregation groups" or "link aggregation" which
involves grouping your connections so that data can travel down more
than one link simultaneously.
This article gives a good overview of Link Aggregation:
"Network Link Aggregation Practices" from Dell
This article gives an overview of configuring link aggregation on Dell switches.
"Link Aggregation on the Dell PowerEdge" by Dell
This article tells you about port aggregation and should give you
enough information on how to configure the switch to enable it.
Dell Support on Port Aggregation:
You should be able to set this all up using your ethernet cabling.
There is a fibre optic alternative but it would be less expensive to
use your ethernet cables.
If you are looking for a fast core switching fabric you may be wise to
purchase a Cisco chassis such as the 4006 with 6 extendable bays
allowing you to have a 48 port switch in one wirespeed device (Can't
get much faster than that!).
site:dell.com link aggregation
site:dell.com port aggregation
If you need any help or additional clarifications, let me know and
I'll be glad to help.