15 ms·
Anatomy of a cheap USB-to-Ethernet adapter
- catch23 13y agoGood article. It reminds me of the stories Wozniak would tell about his chip reduction techniques back when microchips were really expensive.
- gresrun 13y agoWe have used a similar dongle at our company for a 2nd ethernet adapter on our Foxconn-built boxes and found out that they usually don't have unique MAC addresses. This made our lives very difficult because Cobranet audio network uses level-2 addressing. We eventually found a supplier with real MAC addresses.
- nitrogen 13y agoWere you able to get reliable performance sending CobraNet over USB Ethernet adapters? I once wrote a simple audio recording program for the Linux console for diagnosing CobraNet issues, but haven't tried it over a USB adapter.
- userbinator 13y agoYou know it is usually pretty trivial to assign whatever MAC you want to them. (I have an unbranded Android phone that assigns a random MAC address every time I turn WiFi on/off. Apparently this happens since they didn't bother to initialise the EEPROM and just left it at all zeroes. But this means being harder to track, so I consider it more a feature than a bug...)
- rahimnathwani 13y agoDoes it have a legit IMEI? I've read about phones with IMEI set to all zeroes and/or configurable in a secret menu. What model is the phone?
- rahimnathwani 13y agoTo clarify, my interest in whether the IMEI is zeroed and/or programmable is about how the various mobile networks use IMEI, particularly: - China Unicom uses them to detect continued use of subsidized handsets on their network (and will send the customer a text if they're not using it (eg if they've sold their subsidized phone) - I believe T-mobile USA use IMEI to limit access to their 'free data for life' promotion to specific tablet models - Several UK mobile networks have different data tariffs for phones vs. tablets vs. dongles vs. mi-fi devices I'm wondering whether there is any/widespread use of these android devices to bypass restrictions and, eg use a cheaper tablet data plan on a mobile phone with tethering to multiple devices.
- Of_Prometheus 13y agoI've always wondered about the value vs. cost of official products compared with unofficial ones. I always assumed a part of what you were paying for is the brand name, which may be true without knowing just how much of the Apple version's higher price is justified by the extra components/pins, official chip, and protective cover (although I'd think it's a lot). Considering that the difference between the two appears to be higher susceptibility to electrical interference as well as risk of malfunction, and compatibility with non-Apple hardware, the cheaper adapter seems to have much higher value for money. On a technical level, the ingenuity of the people tasked with squeezing comparable performance at 20% of the cost is remarkable - at least to this layman.
- 14113 13y agoThis is interesting - and more importantly, is there any part of the ethernet standard they don't support? I only ask, as at my university there were a number of networks that students simply couldn't connect to if they used any ethernet adaptors. Oddly enough, thunderbolt adaptors, and ethernet on the motherboard worked fine, just USB adaptors didn't work.
- hafflelog 13y agoIf there is a part of the standard they don't support, it's a bug in the component.
- rhizome 13y agoonce upon a time there were chipsets that didn't play well with autonegotiated switch ports.
- nknighthb 13y agoThere have been times in the past when I've found almost every USB ethernet adapter available on the market to be of a single chipset. If one very common chip at that time had a poor interaction with your school's switches, boom. Most of the time, the cheap no-name electronics I've encountered have been pretty feature-complete, or even feature-laden, and any bugs were usually minor annoyances rather than fatal flaws. But the quality control is a crapshoot, so a good chunk of them tend to be DOA. Of the ones that work fine at the start, many will fail in the following weeks, months, and years at much higher rates than you'd expect.
- Eduardo3rd 13y agoOP isn't alone - I find these parts dissections fascinating as well. Posts like these show you how and why hardware is becoming a comodity. It's going to be a very interesting century.
- selectodude 13y agoI'm equally impressed by the Apple adapter. They make expensive stuff, but they legitimately don't cut corners. It's nice to see there's still one consumer electronics company that still does that.
- Vecrios 13y agoWhat do you mean by "[Apple] don't cut corners"? Serious question.
- deleted 13y ago[deleted]
- pndmnm 13y agoAs one possible example, see Ken Shirriff's teardowns of a cheap USB power adapter: http://www.righto.com/2012/03/inside-cheap-phone-charger-and-why-you.html http://www.righto.com/2012/03/inside-cheap-phone-charger-and... And an Apple adapter: http://www.righto.com/2012/05/apple-iphone-charger-teardown-quality.html http://www.righto.com/2012/05/apple-iphone-charger-teardown-...
- learc83 13y agoMost of that had nothing to do with Apple not cutting corners. The Apple device is UL listed, so they can't cut the same corners the Chinese manufacturer can. The same is true of any UL listed USB power adapter.
- wyager 13y agoVery few UL power adapters are as good as the ones Apple makes. I ran a bunch of my USB charger "cubes" at medium load and looked at their output on my o-scope one time. Most of the UL listed adapters had way more noise than the Apple one, even at just 500mA. There was one other manufacturer's charger that was as good as the Apple charger, but I can't remember off the top of my head who it was... I think it might have been HP or Asus or something.
- 13y ago
- chenster 13y agoVery interesting study. Somehow in the back of my head, it still whispers "You get what you paid for".
- kalleboo 13y agoIt's just a shame that it looks like your options are paying $3 for a part that cost $2 to make, or $30 for a part that cost $6 to make
- chenster 13y agoIf so, why don't they make an exact clone of the Apple one at $6 cost and sell it at $15, or even $10? The identical thing but at much better price. Win-win.
- jacob019 13y agoI'm in this business. It's really tough to market based on quality without having a big name, but it's always easy to market based on price. So a few companies offer quality parts at high prices while hundreds of smaller companies fight it out for the low price.
- giovannibajo1 13y agoBecause nobody will buy them because there is no way you can convey the fact that being an exact clone gives more "quality" than being a cheap knockoff. It's already a hard sell a $300 android phone from a $100 android phone, though you would say there is infinitely more differences between the two, compared to two usb-ethernet adapters. Some people will buy Apple just because it's Apple and they want "original" stuff; others will buy Apple because they read these articles and know that the parts are high quality; others will buy the cheapest one they can find among amazon, ebay, monoprice and korean websites (probably laughing at those who buy Apple parts). I don't think there's an easy market for "non-Apple and midprice".
- chockablock 13y ago
- aroch 13y ago>I’d love to learn more about these secretive industries and the engineers who work in them. Isn't it pretty well known that 1) they aren't secretive and 2) they don't actually design their own hardware. They start off by producing the legitimate item, in the factory that's contracted by the company who designed the product. If the product is successful or easily fits in their existing knockoff fabs, they plans are basically copied over
- wtallis 13y agoWhile that does happen, not all knockoffs are just counterfeits made to the approximate specs of the original. There are a ton of knockoffs that have radically different internals that required significant engineering effort to design.
- chockablock 13y agoThe 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 agoWell, 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 agoBut 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.)
- jrockway 13y agoI appreciate the shielding Apple added, especially with two resonators in the HF band. The shielding is, BTW, probably to prevent the device from causing interference, not to prevent other devices from interfering with it. (It's not a radio, after all.) Note that if you do choose to buy the cheaper one without any shielding, it's your responsibility (in the US) to prevent it from interfering with licensed users of the RF spectrum. (In this case, 25m shortwave broadcasters on 12MHz and government-run time-transfer services, like WWV and WWVH, on 25MHz.) If your device is particularly annoying to some shortwave listener, expect to get a letter from the FCC telling you to shut the thing off. (I looked up a few of the letters, and I really appreciate the politeness from the government: http://www.arrl.org/files/file/Part%2015%20Letters/04-06-24-Battery%20Charger.pdf http://www.arrl.org/files/file/Part%2015%20Letters/04-06-24-... "There are several simple and inexpensive steps that can be taken to eliminate interference from battery chargers, and we would be glad to send them to you if needed.")
- streetnigga 13y agoThe complainant even provided the fix (Toroid cores, often seen as those lumps on USB cables) for free, installed and everything. In response the emitting neighbor went and... "You apparently discarded the toroid devices, tossing them in Mr. (deleted) yard. The devices were simple and non-intrusive, and we can envision no reason whatsoever for you not to continue using them, other than a desire to be uncooperative." Dabbling in RTL-SDR for a bit quickly brought me up against the interference monster, and since the USB sticks are typically powered by bus if no direct power modifications are done one of those sources of interference was hooked right into the receiver. Toroid cores either clipped on or looped were indeed the answer for quieting the cable. This doesn't help much if the interfering device is emitting really badly off the board itself though so manufactures shielding their devices as a standard is rather welcome.
- jrockway 13y agoA few letters in, the guy was still being a jerk about it: http://www.arrl.org/files/file/Part%2015%20Letters/04-09-29-Battery%20Charger.pdf http://www.arrl.org/files/file/Part%2015%20Letters/04-09-29-...
- noonespecial 13y agoThe cheap one: looks like we're running without containment, just not enough to cook us.
- naner 13y agoWe use a ton of USB adapters where I work and are using them all day long with several different systems. A few months ago we got a batch of cheap adapters and one noticeable difference was the cheap ones get really hot compared to the more expensive name brand adapters. Appear to work OK, though.
- mdisraeli 13y agoAccording to Bunnie's investigation into microSD cards[1], that low serial number probably indicates that the components were produced on a "ghost shift", when a rogue worker comes in at night and runs the plant off the books [1] http://www.bunniestudios.com/blog/?page_id=1022 http://www.bunniestudios.com/blog/?page_id=1022
- hayksaakian 13y agoGreat read. thanks for the link.
- userbinator 13y agoThe lack of shielding is rarely any problem. Two oscillators is not better than one, since PLLs can generate the required clocks (480MHz = 25 / 5 x 96, 100MHz = 25 x 4, 125MHz = 25 x 5); SMSC has some USB/Ethernet solutions that use the same 25MHz frequency. > The Windows drivers are the exact same digitally signed ones that Microsoft distributes through Windows Update AFAIK there is a standard device class for "USB ethernet controllers", so any chipset that conforms to it will work fine with the standard drivers. As for the unmarked chip - many IC companies are not averse to creating custom designs for a specific customer (and marking it however you want) if you're willing to buy enough. I don't think it's ASIX since they don't have the single 25MHz clock source; more willing to bet on Microchip or SMSC.
- rsynnott 13y ago> I don't think it's ASIX since they don't have the single 25MHz clock source; more willing to bet on Microchip or SMSC. Note that it identifies itself to the system as ASIX, though. Of course, it could be that other companies actually have a license to make ASIX things...
- userbinator 13y agoUSB descriptors are programmed in the EEPROM, so they could've made it identify itself as anything they wanted. If you can dump the EEPROM, that can provide more clues - the configuration format does differ between manufacturers.
- angusgr 13y ago(Blog author here) You're spot on about the PLL stage, a few people on Reddit pointed the same thing out when I first posted it. Makes sense, although I still think it's interesting they added it internally to an otherwise (apparently) cloned design. You're also right that USB CDC does provide the option for a generic USB Ethernet device, however this silicon is ASIX-specific (not just the USB IDs.) ASIX's Windows drivers include their own system driver binaries, and the ASIX Linux driver has a lot of ASIX-specific stuff in it. I think it's kind of possible ASIX made this themselves as some kind of no-name branded unadvertised market segmentation effort. I can't understand what their rationale would be exactly but hardware companies do unusual things sometimes...
- bane 13y agoGreat writeup. So I guess the question is, is the one with the fruit on it worth $25 more? It seems like the cheap one is more "Wozniak" in approach.
- EpicEng 13y agoThe problems I have run into with the cheap versions of hardware like this is that they tend to fall apart. For example, my last mini-DVI to HDMI adapter performed just fine... until the glue holding the female end in broke loose. I glued it back, and then the plastic started to crack. The guts of it (the electrical bits) looked fine, worked properly, etc. It was the mechanical design that gave me problems. Replaced it with a (ridiculously expensive at $29.99) higher end version and that has lasted me quite some time.
- rsynnott 13y agoWell, note that the cheap one is somewhat slower in the iPerf test (though, for the sorts of things people use ultra-cheap ethernet adaptors for, this would rarely matter). Also, while I'm not sure if it's the case for this one, a lot of ultra-cheap network hardware has the same MAC address for _every device in existence_, which can cause entertaining issues.
- Tomdarkness 13y agoI recently purchased a Gigabit ethernet adapter for my rMBP. If you're fine with something a bit larger and are willing to go above "dirt cheap" I'd strongly recommend the Inateck HBU3VL3-4. It's made by a German company so I'm not sure how available it is over in the USA. It has an ASIX AX88179 which is a USB 3.0 to Gigabit chip and it my tests I was easily able to get around 800-900Mbps. It also has 3x USB 3.0 ports, so not only do you not lose your USB 3.0 port you gain 2 more. I've not dismantled it but it feels solidly built. Here in the UK I paid the same price as the Apple USB to Ethernet Adapter, which is only 100BASE-T and offers no hub.
- rsynnott 13y agoNote that Apple also make a Thunderbolt gigabit adaptor for the same price.
- darrenkopp 13y agoFantastic, I'm in the market for a USB gigabit ethernet adapter as the thunderbolt one from Apple (and all other thunderbolt adapters it would seem) disable the sleep on windows. I found this on Amazon in the US under the brand "Unitek." http://www.amazon.com/gp/product/B00EHDNAOE/ref=as_li_ss_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B00EHDNAOE&linkCode=as2&tag=diaryofamadma-20 http://www.amazon.com/gp/product/B00EHDNAOE/ref=as_li_ss_tl?...
- vdm 13y agoI use Plugable on Mac; great as well. http://plugable.com/products/usb3-e1000 http://plugable.com/products/usb3-e1000 http://www.amazon.co.uk/dp/B00AQM8586 http://www.amazon.co.uk/dp/B00AQM8586
- rahimnathwani 13y agoThe taobao link in the original post leads to a listing which does not specify the chipset or support for Mac. This suggests it's a cheaper chipset. The 4-5 best-selling cheap USB-to-Ethernet adapters on taobao use the RD9700 chipset, and can be had for 22RMB including shipping. The cheapest Asix 88772-based one I can find from a reliable seller is 25RMB including shipping. It seems like there is another 50 cents that can be cut from the design, although the RD9700 may not have an OSX driver: http://forums.macrumors.com/showthread.php?t=1450026 http://forums.macrumors.com/showthread.php?t=1450026
- userbinator 13y agoThe RD9700 is "USB 2.0" and what they don't tell you is that it's actallly "USB 2.0 (FS)", i.e. the 12Mbps full speed mode. It also comes in a 32-pin package, and comes from a shady-looking company (http://www.corechip-sz.com/ http://www.corechip-sz.com/ ) that has parts numbered 6872 and 6873, so the "RD6877" on the PCB of OP's clone suggests it might be a RD6877.
- rahimnathwani 13y agoWow, good spot! Does that mean the RD9700 devices on taobao (22RMB) are likely to work on OSX without additional drivers, as they pretend to be an Asix chipset? The speeds OP got are higher than 12Mbps, so I guess it's not an RD9700 in disguise. Just guessing. I'm about to order the 25RMB asix-type one.
- rahimnathwani 13y agoFor reference this is the one I'm going to order: USB网线转换器笔记本网卡以太网转网线 windows全通用型MAC免驱 http://tb.cn/nmLpZey http://tb.cn/nmLpZey
- rahimnathwani 13y agoI received my adapter. The windows driver (automatically downloaded from Microsoft) reports that it's not a genuine Asix chip. The message is the same as described in this document: http://www.asix.com.tw/FrootAttach/userguide/How_to_identify_Authentic_ASIX_USB-to-LAN_Products_v100.pdf http://www.asix.com.tw/FrootAttach/userguide/How_to_identify... It seems to work fine on a Mac, though.
- chrislaco 13y agoAnyone done a writeup like this, but for mdp -> dvi adapters... Apple vs Monoprice, etc?
- chockablock 13y agoMini DisplayPort -> single-link DVI-D is just a passive cable adapter, so a lot harder to screw up. (And even less reason for it to cost $29, but that seems to be Apple's default minimum price for an accessory.)
- analog31 13y agoAn old analog hacker rule of thumb is that if your product is going to emit RF, you'll find spurious RF on input and output terminals (including ground terminals), which you can check with a scope. Such a pre-test is cheaper than getting a field test done and failing. The scope test might be do-able on a comparison basis between the two designs. It's possible that Apple over-engineered their shielding. It's not necessarily a cloned design. The cheap part may simply implement standard protocols, and use the name of the Apple part to ensure driver compatibility without too much testing. Still, that seems rather under-handed if it's what it seems.
- mariuolo 13y agoLove that blog, thanks for pointing me at it.