Thanks for the great review !
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Linux Tests Of The QNINE M.2 NVMe SSD Enclosure To USB-C Adapter
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On the ASUS PRIME Z390A board, the 2nd M.2 slot can accept a properly keyed SATA SSD, but it will consume a resource from the onboard SATA controller. You have to enable it in the BIOS.
The JMicron NVMe to USB 3.1 Gen 2 controller uses 2 PCIe lanes (v3) to communicate with the SSD.
Based on Michael's tests, the adapter is fully using the maximum bandwidth available via the USB port and controller.
What I am concerned about is the 870EVO performance in the M.2 slot alone.
The Z390 has a very unique approach to USB control, especially between Gen 2 mode (where it needs to detect voltage on the C port) and Gen 1 and lower (A ports).
If it detects voltage on the C port it uses 20:f0, if it doesn't detect voltage it uses 20:f1 via the xDCI interface.
It sounds like Intel has essentially placed a USB switch and voltage detection determines the route on the PCIe bus.
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Originally posted by PCJohn View PostSurely, you was not IT guy that time.... USB was a huge step forward over connecting the things over serial (or even parallel) port. Installing drivers for serial devices was troublesome and painful. Configuring programs to use them required much of configuration: setting baud-rate, number of stop bits, etc.
Originally posted by PCJohn View PostUSB was a huge step forward. USB 2.0 was finally something reliable and fast enough for most of the things of that time (maybe, not for you). Firewire was there but did not get widespread use. I never had a single device. Complain or not, it never got widespread use in circles around me, same as SCSI disks. Anyway, I am happy that you are finally happy with USB 3.1.
But if 30 MB/s USB2 works for you, hey that's great for you. I'm just glad that after 23 years of waiting for v3.1, we finally have a USB that doesn't suck.Last edited by torsionbar28; 26 March 2019, 02:28 PM.
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Originally posted by torsionbar28 View PostSounds like you're confused here. RS232 devices do not require drivers.
Originally posted by torsionbar28 View PostTheir simplicity is why they are still in use today. Baud, data bits, parity, and stop are the only parameters. Not that you ever have to change them, as nearly everything uses 8/N/1. USB on the other hand, was a complicated cumbersome mess, where every device requires a driver, Windows users call this "driver hell". Remember when Bill Gates did a live demo of Windows 95? He plugged in a USB device and the whole OS crashed with BSOD, for the world to see. No such problems with RS232 serial. BTW my first PC was a Compaq 286 with 1200 baud modem...
Originally posted by torsionbar28 View PostIncorrect, most pro audio/video equipment was firewire only. Because USB 2.0 was so crappy and slow, high bandwidth devices all came in Firewire versions, for people who care about performance.
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Originally posted by PCJohn View PostI might be mistaken on this point, but how would you connect a printer?
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Originally posted by torsionbar28 View PostUSB 3.1 uses UASP for storage, so full SCSI command set is available. USB prior to 3.1 was junk, with junk protocols and implementations that were hit or miss on SMART. USB 3.1 fixes this mess finally.
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Originally posted by torsionbar28 View PostRS232 devices do not require drivers. Their simplicity is why they are still in use today. Baud, data bits, parity, and stop are the only parameters. Not that you ever have to change them, as nearly everything uses 8/N/1.
USB on the other hand, was a complicated cumbersome mess, where every device requires a driver,
Windows users call this "driver hell".
Remember when Bill Gates did a live demo of Windows 95? He plugged in a USB device and the whole OS crashed with BSOD, for the world to see. No such problems with RS232 serial.
Incorrect, most pro audio/video equipment was firewire only.
When you have large audio and video data to move around, USB2 was simply too slow.
Laptops had some EsataP ports https://en.wikipedia.org/wiki/ESATAp with combined esata and power for an external drive.
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Originally posted by torsionbar28 View PostMcDonalds restaurants are widespread. Widespread != good. Some folks prefer 'good'. For everyone else, there's the dollar menu.
The point was "Firewire was not widespread", and "most pro audio/video equipment" is still a niche so even if Firewire did rule in this niche (I was there so I remember it did), you can't say it's widespread.
Also don't try to make Firewire look like a fine choice for fine people, it was used only because it was faster.
Most of its very cool features have always been irrelevant (I'm probably the only one left that actually knows what you could do with it, daisy-chaining, devices writing and reading independently on other devices in the daisy chain, sharing a network through devices in the chain, and others).
That's why it basically stopped being developed as soon as eSata appeared, and dropped entirely as soon as USB finally catched up.
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(I understand this thread is nearly a year old, but this is the only such discussion on Phoronix, and hope this helps someone)
Originally posted by dwagner View PostYou don't really have to guess, since [the JMicron JMS583] is currently the only NVMe <-> USB 3.1gen2 chip on the market. German c't magazine recently tested two such external enclosures ... with similar results: The connection is simply unstable with all enclosures using this chip, and not only under Linux.
I guess we'll have to wait for the ASMedia ASM2364 chip to hit the market before expecting different results.
BTW, curiously enough there was a new controller type, the Realtek RTL9210 that I'd heard was supposed to be good, too- but it suffered from the same issues as the JMicron controller, and would get reset by the USB when the queue depth got too high. This, too must have been power related, as it also didn't do it when connected to my TB dock.
Thankfully Amazon has a generous return policy.
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