Daniel Stenberg <dan...@haxx.se> 于2020年6月16日周二 下午10:50写道： > > On Tue, 16 Jun 2020, Hongyi Zhao wrote: > > >> Are these transfer speeds somewhat stable and reliable in repeated tests? > > > > I've conducted several tests at different times against this URL using both > > curl and IDM, though the speeds may vary each time, IDM always beats curl. > > The huge difference is what makes this so weird. I mean, I wouldn't be > surprised if a Windows-specific tool maybe can do transfers slightly faster > somehow when tickling the OS the right way, but I can't understand what would > make the difference that big. To me this smells like a setting/config > somewhere that needs to be tweaked or something, rather tham just a basic > software architectural mistake or overhead. > > Uh, but you compare against curl on Ubuntu?
Maybe I should have told the testing environments more clearly. Anyway, I describe again on the testing environments in a more detailed way as follows: All testings are done on Ubuntu 20.04. Curl is installed from the distro's repo. I'm a registered user of IDM, and the IDM latest version is run from within wine [1] git master version compiled by myself on Ubuntu 20.04. [1] Wine source code is cloned from here: https://source.winehq.org/git/wine.git > IDM is a Windows-only tool, right? Yes, but I run it from within wine on Ubuntu 20.04, as told above. > You're *sure* there aren't differences between the different system setups > that could explain for (parts of) this? Wouldn't it make more sense to compare > with curl running on the same Windows machine than runs IDM? I don't have machine which running Microsoft Windows, so I cannot do the testings on Windows machine. > > >> Do the same symptoms reproduce even if you don't use a SOCKS proxy? > > > > It seems this URL is banned for my location. Without using the socks5 proxy, > > the connection won't be established. > > If you try against other test servers/proxies, I presume you see similar > differences as well? I've tried with this URL (https://mirrors.tsinghua.edu.cn/ctan/systems/texlive/Images/texlive2020-20200406.iso) which don't be banned for my location without using any proxy, and the results is the same: IDM beats curl. > > >> From my dev machine in Sweden, my curl reached 30MB/s from this URL. > > > > Have you also tested with IDM for comparison just like I've done? > > I don't have a comparable Windows setup to test on. Also, this application is > a commercial one that isn't open source so I rather avoid it for that reason > too. > > BTW, if curl is slow then surely you could also get faster download speeds > with other transfer tools? Have you identified any such, that perhaps runs on > Linux? To be frank, it seems there is no other tool/library on Linux which can afford so many features as (lib)curl. I really feel so difficult for me to find an alternative one which support multi threading (in library mode), http(s)/socks4/5 proxies supporting, and so on. > > >> I'm not aware of any. Reading on the IDM site, it seems very content about > >> its use of multiple connections and ranges to download data. > > > > All these techniques can also be done with libcurl-multi which is one > > of the goals of this project: https://github.com/pyIDM/PyIDM > > I'm aware. I'm just trying to make sure that we compare apples with apples. > > > Interesting. IMO, the curl itself doesn't support multi threading technique, > > It's not so much a threading issue as multiple TCP connections Still interesting again. Is there any example for libcurl to establish multiple TCP connections within one threading? > that's going to make a difference. > > > and for IDM, I set the max. conn. number = 1 for testings. > > > > But here, you told `a single TCP stream `. I still cannot figure out how to > > check or ensure I'm meeting this condition. Any more hints? > > I can only think of using wireshark or something to verify what's going on > under the hood but I guess that we also have no actual reason to suspect that > "conn. number = 1" isn't actually limiting the number of connections to 1. So, here, by saying *connections*, you still refer to TCP connections, instead of the number of thread/process. Regards, -- Hongyi Zhao <hongyi.z...@gmail.com> ------------------------------------------------------------------- Unsubscribe: https://cool.haxx.se/list/listinfo/curl-library Etiquette: https://curl.haxx.se/mail/etiquette.html
