On Sun, Sep 12, 2021 at 03:43:17PM -0700, Keith Lofstrom wrote: > 870 QVO (4 bit NAND) $110 > 870 EVO (2 bit NAND) $160 > 860 PRO (1 bit) $200 ... at Newegg, also Amazon.
Turns out that BestBuy sells the 1TB 870 EVO for $150, so I bought two online from their nearby store. Sadly, curbside pickup requires a dodopaddle connected their website. I am spyware-averse and therefore de-dodo'ed, so I had to walk inside for two minutes (masked and shielded). Sigh. Retail store replenishment still incurs some freight transport and road risk, but vastly less than an individual UPS shipping box from Newegg in southern California. I'll put Mate Ubuntu LTS on the drive (or perhaps a light- weight Debian variant) and plug it into an old Thinkpad X61 Real Soon Now. ----- The retail box is 90g and 165x99x21 mm. The manual is 13g, 80% legalese in a dozen languages. The drive is 47g and 100x70x7 mm; it feels hollow. The case closes with three 5-pointed star Torx-like screws, two under the label; opening it for a look voids the 5 year warranty. So, I looked at someone else's drive innards instead: https://pcper.com/wp-content/uploads/2021/01/samsung-ssd-870-evo-1tb-review-on-kitguru-internal-1.jpg An amazingly small board. The rectangular gray package on the bottom is probably the memory, containing many stacked silicon films. The 2TB and 4TB versions have more memory packages and more films; here's the 4TB 870 QVO (4 bits per cell, twice as dense as EVO): https://pcper.com/wp-content/uploads/2020/07/samsung-ssd-870-qvo-4tb-review-on-kitguru-openenclosure-1023x640.png The two rows of 5/7 holes and the pad pair on the bottom may be for test probes and circuit-board-to-chip connectivity testing with IEEE 1149 boundary scan, the first go/nogo test for the board. I helped write and verify the IEEE 1149.4 analog boundary scan standard, also an extension for high speed timing test using low speed interconnect. Using the 1149 and the extension, every connection and discrete component can be tested, perhaps even the connections to the SATA plug on the left. The capacitance of those pins will be abnormally low if the traces or solder connections are open. I'd guess the rightwards-pointing internal test connector towards the center of the photo is for post-assembly burn-in test; imagine large test board with hundreds of these tiny boards plugged into it, testing and data-logging for days in a large temperature-cycling oven. Presumably 99.9% automated, with human technicians ungumming the works 0.1% of the time, and managers ungumming (or gumming) the technicians +/- 0.02% of the time. ---- Enough blovating, back to distro-wrangling. Keith -- Keith Lofstrom kei...@keithl.com
