Memory
Dolphin: N/A. Dolphin's graphics chip alone will feature up to 16Mb of embedded DRAM though.
PlayStation 2: 32Mb Direct Rambus RAM
Dreamcast: 16Mb (plus 8Mb Video RAM, 2Mb Sound RAM)
Nintendo 64: 4Mb (+parity) Rambus D-RAM (expandable to 8Mb)
PlayStation: 2Mb (plus 1Mb Video RAM, 512kb Sound RAM)

Memory Bus Bandwidth
Dolphin: 3.2 Gb/s (Gigabytes per second)
PlayStation 2: 3.2 Gb/s (Gigabytes per second)
Dreamcast: 800 Mb/s (Megabytes per second)
Nintendo 64: 500 Mb/s (Megabytes per second) or about 0.5 Gb/s
PlayStation: 132 Mb/s (Megabytes per second)

Software Format
Dolphin: DVD, 4.7 Gb capacity
PlayStation 2: DVD, 4.7 Gb capacity
Dreamcast: Propriety CD, 1 Gb capacity
Nintendo 64: Cartridge, 64Mb capacity (so far)
PlayStation: CD, 650 Mb capacity

Will Dolphin play N64 cartridges?
No, obviously. The console will utilise a Matsushita-manufactured DVD-ROM for games as large as 4.7 Gb. The next-generation console will not be backwardly compatible with N64 games for three major reasons:
1. Dolphin's internal architecture is entirely different from that of the N64.
2. Dolphin is a DVD-based console.
3. Backwards compatibility is not important enough to justify a significant increase in the price of the console in order to implement it.

Will Dolphin be able to play DVD movies?
Although it is suspected that the console will indeed be able to play DVD movies, Nintendo have not confirmed this feature as yet.

How does Nintendo's planned N64 add-on device 64DD fit in, if it all?
As far as we know, it doesn't. It's likely that Nintendo will incorporate some of the DD's talked-about features into Dolphin, but that's as far as it goes. The 64DD is still on schedule to launch in Japan "soon," with no word of a US or European release. Just how much weight Nintendo will actually throw behind the device is debatable, especially since it has been all but shunned by developers and only has a handful of titles to show for its numerous delays. It's not out of the question to assume that Nintendo will carry the DD's anticipated writability options over to Dolphin, at least to some degree.

Will the Dolphin have a modem?
Absolutely. Although Nintendo have not officially announced the specifics in relation to their Internet/Network strategies for Dolphin, they did recently confirm that they are in the works. That's good because, put simply, the company must include support for a modem if Dolphin is to compete with Sega and Sony's machines. An announcement regarding Dolphin's modem technology is expected to be made in a few months.

Will the modem come packaged with the system?
Unknown at this time. It should be noted, however, that Sega recently confirmed Dreamcast will launch in the US with a modem. We ask that you bear that in mind.