On Wednesday 18 September 2019 12:58:25 Jonas Smedegaard wrote: > Quoting Gene Heskett (2019-09-18 18:20:43) > > > On Wednesday 18 September 2019 11:36:41 John Hasler wrote: > > > Jonas writes: > > > > Please demonstrate just one single example of dd being faster > > > > than cp to transfer a full raw image to a raw device! > > > > > > On modern systems you would probably need to be doing terabyte > > > transfers between disks on the same machine. Back in the days > > > when a megabyte was a lot dd was *much* faster. > > > > > > On an SD card I think that the write speed of the card is probably > > > the limiting factor. > > > > It is, and the makers lie a lot, taking advantage of the buffering > > to get thier 100 MBs rating for small writes. For gigabyte transfers > > I often see sub 20 MB/S toward the end. But you may want to steer > > clear of the 64GB+ cards, exfat is creeping into the sdhc arena, and > > I either have a defective NEW PNY 64GB, or this stretch install > > can't touch it because its exfat. I bought 2 recently, same exact > > part number, slightly different card gfx, the 85 meg rated one > > doesn't mention exfat, works, the 100 MB/S rated one mentions exfat > > and is untouchable. > > Regarding quality of SD cards, I trust advices from Thomas Kaiser. > > Here's his advice on which brands to trust: > > Only a few vendors on this planet run NAND flash memory fabs, only a > > few companies produce flash memory controllers and have the > > necessary know-how in house. And only a few combine their own NAND > > flash with their own controllers to their own retail products. > > That's the simple reason why at least I only buy SD cards from these > > 4 brands: Samsung, SanDisk, Toshiba, Transcend > > Above quote is from > https://forum.armbian.com/topic/954-sd-card-performance/page/3/?tab=co >mments#comment-49811 which is linked from front page intro to that > thread - as part of this more general advice + warning not to waste > time reading the whole > > thread: > > Warning: This whole thread is only about historical information now > > since it's 2018 and we can buy inexpensive and great performing A1 > > rated SD cards in the meantime. Buying anything else is a mistake so > > directly jump to the end of the thread for performance numbers and > > recommendations. > > On a related note, here's Kaiser's more detailed notes on A1/A2 > rating: > https://github.com/ThomasKaiser/Knowledge/blob/master/articles/A1_and_ >A2_rated_SD_cards.md > That also seems to be somewhat dated. And rather Sandisk promoting. So I bought another to see if they were still as bad as a year ago. About a buck cheaper than the other name brands. I don't have any left from the 3 or 4 I did have, having destroyed the last 32GB in the after install update of about 300 pkgs. So my preference has been not to buy any more SanDisk.
I was going to get another micro hdmi adapter but somebody bought the last one and its peg has been re-assigned to something else. So I'm stuck playing over an ssh login till whenever. > > - Jonas Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene>
