On Tue, 2023-06-27 at 15:31 -0400, Steven Friedrich wrote: > I want to know transfer statistics, i.e., max speed, min speed, avg > speed when I copy to/from a usb device to/from hdd/ssd. > Please enhance cp utility to provide this info. A cmdline switch could > request this report.
Hi, the Internet provides a lot of alternative Linux commands in reply to similar request's as yours. While you can get the wanted statistics, those statistic gain you absolutely nothing, they will confuse you, since such statistics do suffer from the same issue as a diff does, to check the integrity of backups. Files might or might not be cached. Benchmark tests are disputed, but there are certainly very good scientifically based tests. If you would use rsync instead of copy, you could get the wanted, but quite useless kB/s information. How to do good benchmark tests has to do a lot with the skills of the person doing the tests. Apart from the cache I provide another example later. > While shopping for usb cables, I discovered MOST USB cables are only > capable of usb 2.0 speeds (480 Mbps). I don't experience the same. IOW it probably depends where you go shopping for USB cables. > I need more info from utilities and widgets. > Can a usb driver detect the capabilities (transfer speed) of a usb > device/cable? Checking the quality of a cable is tricky what ever tools/"meters" you are using. It's possible to get reported information from a device, but you cannot trust this information. The f3 tool for example can be used to check if the reported size is correct or a fraud. However, back to the speed and another example that make good benchmark tests that difficult. USB3 unlikely is a bottleneck, more likely it's a HDD behind the USB controller. Only buy HDDs if the dealer provides information, if the HDD is a SMR or CMR. Note, the vendors started selling HDDs from the same series that once were CMR, since a long time ago as SMR. When using SMR the speed varies a lot. Testing SSD speed is also a topic on its own. What are you doing that SSD speed is that important to you? If SSDs should be a bottleneck, then maybe you need to change your workflow or your setup (file system, options, tmpfs etc.). > The industry is getting away with obfuscation. Yes and no, this is a topic on its own. Sometimes it's also related to consumers who don't want to learn the truth. If you buy the most expensive camera, but the cheapest lenses, the photos are much likely less good than those made with the cheapest camera, but the most expensive lenses. John and Jane consumer usually buy every now and than a new camera in a bundle with kit lenses, instead to keeping the old camera and buying decent lenses for the old camera. Regards, Ralf -- Ubuntu-devel-discuss mailing list Ubuntu-devel-discuss@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel-discuss
