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The example in the article is of a functional cloned part that has half as many pins, and needs only 1 external oscillator instead of 2. Author does not decap

The example in the article is of a functional cloned part that has half as many pins, and needs only 1 external oscillator instead of 2. Author does not decap the chip, but the implication is that there was indeed some real engineering that went into the design of the clone.

thrownaway2424 13y ago
Well, maybe. The original has 47 power pins, more than the counterfeit has any pins. It's likely that the original designers included these to improve noise margins in various parts of the chip. It's also likely that the 32-pin version has rather worse problems with power and ground noise. It _is_ possible, of course, that the original has excessive margins and the counterfeit one is a tighter design. We'd have to see the eye diagrams on both sides to be sure.
- userbinator 13y ago
  But all of that speculation is not comparable to actually seeing the clone work in real-world situations. I would've liked to see the OP do a benchmark on transfer rates between the original and the clone. (Unless he aleady did one and didn't find any difference.)
  - rsynnott 13y ago
    From the post: "When I ran a TCP throughput test with iperf, they both performed well. The Apple adapter measured throughput of 94.3Mbps. The cheap adapter measured 87.4Mbps. By comparison, the builtin ethernet on my laptop measured 94.8Mbps (after being set from gigabit to 100Mbps.)" So, there is a difference, but it's relatively small (and possibly acceptable for the things people use ultra-cheap ethernet adaptors for).
    - userbinator 13y ago
      Sorry, didn't see that (just dived right into the teardown. :) So it's a ~7% difference, indicating that it's not a straight clone but different silicon with a compatible interface.
    - thrownaway2424 13y ago
      It might work well when attached to another device with high (i.e. industry-normal) noise margins. I'd be quite interested to see the performance of two adapters connected together, or connected with a cable wrapped 10 times around a pencil.
    - foobarian 13y ago
      I would've liked to see a UDP based packet loss report, and also at a couple of different packet sizes. The throughput drop could be due to packet loss, maybe from more noisy circuitry, or it could be due to a bottleneck on the USB side of things. Smaller packets are good at finding those because they generate more events per unit time. I saw this with a bunch of crappy WiFi dongles. The radio can run at the 54Mbps or whatever but the USB interface tops out at 20.
      - deleted 13y ago
        [deleted]

thrownaway2424 13y ago

Well, maybe. The original has 47 power pins, more than the counterfeit has any pins. It's likely that the original designers included these to improve noise margins in various parts of the chip. It's also likely that the 32-pin version has rather worse problems with power and ground noise. It _is_ possible, of course, that the original has excessive margins and the counterfeit one is a tighter design. We'd have to see the eye diagrams on both sides to be sure.

userbinator 13y ago
But all of that speculation is not comparable to actually seeing the clone work in real-world situations. I would've liked to see the OP do a benchmark on transfer rates between the original and the clone. (Unless he aleady did one and didn't find any difference.)
- rsynnott 13y ago
  From the post: "When I ran a TCP throughput test with iperf, they both performed well. The Apple adapter measured throughput of 94.3Mbps. The cheap adapter measured 87.4Mbps. By comparison, the builtin ethernet on my laptop measured 94.8Mbps (after being set from gigabit to 100Mbps.)" So, there is a difference, but it's relatively small (and possibly acceptable for the things people use ultra-cheap ethernet adaptors for).
  - userbinator 13y ago
    Sorry, didn't see that (just dived right into the teardown. :) So it's a ~7% difference, indicating that it's not a straight clone but different silicon with a compatible interface.
  - thrownaway2424 13y ago
    It might work well when attached to another device with high (i.e. industry-normal) noise margins. I'd be quite interested to see the performance of two adapters connected together, or connected with a cable wrapped 10 times around a pencil.
  - foobarian 13y ago
    I would've liked to see a UDP based packet loss report, and also at a couple of different packet sizes. The throughput drop could be due to packet loss, maybe from more noisy circuitry, or it could be due to a bottleneck on the USB side of things. Smaller packets are good at finding those because they generate more events per unit time. I saw this with a bunch of crappy WiFi dongles. The radio can run at the 54Mbps or whatever but the USB interface tops out at 20.
    - deleted 13y ago
      [deleted]