How fast ADSL an Amiga 1200 can handle? (Router-> NIC-> PCMCIA port)

[Trev]

And it is, of course, more complicated than that. Data rates use powers of ten, so 10 Mbps = 10,000,000 bps = 1,250,000 bytes per second. Throughput in TCP/IP is a ratio of receive window size to latency, bounded by bandwidth.

For example, a default AmiTCP configuration with a receive window of 4,096 bytes has a maximum transatlantic (~45ms latency) throughput of 728,177 bps = ~89 kilobytes per second. To approach the theoretical maximum of 10 Mbps, you need a receive window size of 56,940 bytes (always a multiple of the TCP MSS of 1,460 bytes).

Transamerican latency is ~85ms, so you'd need a receive window size of 128,480 bytes (64,240 bytes scaled once) to reach 10 Mbps. I don't know off the top of my head if AmiTCP supports window scaling.

None of these numbers takes into account system speed and application and stack processing time.

[Trev]

Both should be idle unless a packet is sent or received or some other monitored interrupt is triggered. Received packets should only be sent to the protocol stack if there's a pending I/O request; otherwise, the ISR will drop/ignore the packet.

[Trev]

With a 10 Mbps interface? Exactly the same speed. With a 100 Mbps interface? The upper bound is higher, assuming your peripheral bus provides enough bandwidth, but the same basic rules re: actual throughput still apply. I don't think any classic Amiga system, regardless of processor, can process data quickly enough for a 1 Gbps interface. A G-Rex on a Blizzard PPC might reach half that if the system was doing nothing but pushing raw Ethernet frames. Anything faster than that is obviously out of the question unless you build a custom interface with a very, very, very large buffer.