Differenza:  tra 5V e 3.3V PC cards & CardBus cards.

Sopra:   PCMCIA CardBus Card (32 Bit, 3.3V)

 Sotto:   PCMCIA Type II Card (16 Bit, 5V)       

PC Card Type I     =  16-bit  68 pin  3.3 mm.      24MB/s Max teorici (bus ISA equivalente)

PC Card Type II    =  16-bit  68 pin  5.0 mm.      24MB/s Max teorici (bus ISA equivalente)

PC Card Type III   =  16-bit  68 pin  10.5 mm.     24MB/s Max teorici (bus ISA equivalente)

CardBus Type II   =  32-bit   3,3 Volt   33 MHz. 132MB/s Max teorici (bus PCI equivalente)

PC Card/CardBus Throughput theoretical maximums are as follows:

16-bit I/O Transfers (255 ns Minimum cycle)
* Byte mode: 3.92 Mbytes/sec
* Word mode: 7.84 Mbytes/sec

16-bit Memory Transfers (100 ns Minimum cycle)
* Byte mode: 10 Mbytes/sec
* Word mode: 20 Mbytes/sec

CardBus (32 bit burst mode)
* Byte mode:      33 Mbytes/sec
* Word mode:     66 Mbytes/sec
* DWord mode: 132 Mbytes/sec

Please note that actual throughput may be substantially less than the theoretical maximums of the interface.

fonte: http://www.pcmcia.org/pccard.htm  -  prova pratica 

ExpressCard   =  54 mm   250MB/s Max teorici (bus PCI Express equivalente) 1,5 Volt

ExpressCard   =  34 mm   250MB/s Max teorici (bus PCI Express equivalente) 1,5 Volt

CardBus         =  54 mm   132MB/s Max teorici (bus PCI equivalente) 32-bit   3,3 Volt   33 MHz.