4%. Ethernet has a minimal overhead with the header being 26 bytes. However, Ethernet frames do carry other protocol packets in them which have headers too.

4. Interoperability

Different Ethernet versions work well together. However, ATM has a far tougher time since large parts of networking applications have been built for traditional LANs. Some of the applications would, therefore, have to be changed for ATM. MPOA, Multiprotocol over ATM, attempts to make existing LANs and their protocols interoperate with ATM and gradually replace LANE, another program that is currently accelerating adoption of ATM.

5. Management

Ethernet is superior to ATM in installation and configuration. Its installing is simple and easily comprehensible. ATM installing is more complex and demands certain expertise. This, in turn, makes the technology pricier.

6. Price

Ethernet is far cheaper than ATM in all aspects of its system including...

In fact, a transition to an ATM LAN is more expensive than an Ethernet upgrade.
Conclusion

It seems clear that Ethernet is superior to ATM in almost all ways. These include speed, simplicity, price, interoperability, and management.

ATM has the advantage in overhead and scalability. Nonetheless, ATM still has an established position in Internet backbones and here Ethernet cannot replace it, a t least at the moment. Ethernet's niche is with LANs.

Quality of service is another huge factor and here ATM has the clear advantage with Ethernet still to work on this. Each system, accordingly, has advantages and disadvantages that the other lacks giving each its separate sector.

Source

Tomi Mickelsson (1999) ATM vs. Ethernet Helsinki University of Technology

http://www.tml.tkk.fi/Opinnot/Tik-110.551/1999/papers/07ATMvsEthernet/iworkpaper.html