From: Tomek C. <tom...@gm...> - 2010-10-11 14:55:44
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Dear libusb developers, As you have great insight into USB transfers, please advise on optimal pendrive transfer size. Is it 10240 as stated in FreeBSD's announcement (I have seen 64k in other place)? # dd if=8.1-RELEASE-amd64-memstick.img of=/dev/da0 bs=10240 conv=sync Please advise, Tomek -- CeDeROM, SQ7MHZ, http://www.tomek.cedro.info |
From: Alan S. <st...@ro...> - 2010-10-14 17:08:16
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On Mon, 11 Oct 2010, Tomek CEDRO wrote: > Dear libusb developers, > > As you have great insight into USB transfers, please advise on optimal > pendrive transfer size. Is it 10240 as stated in FreeBSD's > announcement (I have seen 64k in other place)? > > # dd if=8.1-RELEASE-amd64-memstick.img of=/dev/da0 bs=10240 conv=sync The size you use in the dd command doesn't much matter. It affects only the transfers made between dd and the operating system, not the tranfers between the operating system and the pendrive. Alan Stern |
From: Tomek C. <tom...@gm...> - 2010-10-14 17:36:06
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On Thu, Oct 14, 2010 at 7:08 PM, Alan Stern <st...@ro...> wrote: > On Mon, 11 Oct 2010, Tomek CEDRO wrote: > >> Dear libusb developers, >> >> As you have great insight into USB transfers, please advise on optimal >> pendrive transfer size. Is it 10240 as stated in FreeBSD's >> announcement (I have seen 64k in other place)? >> >> # dd if=8.1-RELEASE-amd64-memstick.img of=/dev/da0 bs=10240 conv=sync > > The size you use in the dd command doesn't much matter. It affects > only the transfers made between dd and the operating system, not the > tranfers between the operating system and the pendrive. > > Alan Stern Hello Alan and thank you for your response! So there is no need to pass the "bs" parameter, as the OS will choose its own value anyway during the data transfer to the pendrive? Best regards, Tomek -- CeDeROM, SQ7MHZ, http://www.tomek.cedro.info |
From: Alan S. <st...@ro...> - 2010-10-14 17:42:04
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On Thu, 14 Oct 2010, Tomek CEDRO wrote: > On Thu, Oct 14, 2010 at 7:08 PM, Alan Stern <st...@ro...> wrote: > > On Mon, 11 Oct 2010, Tomek CEDRO wrote: > > > >> Dear libusb developers, > >> > >> As you have great insight into USB transfers, please advise on optimal > >> pendrive transfer size. Is it 10240 as stated in FreeBSD's > >> announcement (I have seen 64k in other place)? > >> > >> # dd if=8.1-RELEASE-amd64-memstick.img of=/dev/da0 bs=10240 conv=sync > > > > The size you use in the dd command doesn't much matter. Â It affects > > only the transfers made between dd and the operating system, not the > > tranfers between the operating system and the pendrive. > > > > Alan Stern > > Hello Alan and thank you for your response! So there is no need to > pass the "bs" parameter, as the OS will choose its own value anyway > during the data transfer to the pendrive? Yes, the OS will choose its own value during the data transfer to the pendrive. However the "bs" parameter you specify _does_ affect the transfers between dd and the OS, so you might want to use something larger than the default. Alan Stern |