Wikipedia:Reference desk/Archives/Computing/2017 December 9

= December 9 =

USB Hub
I have a new, powered, USB Hub, and though I know that it is plugged into a power outlet and is plugged into the back of my Apple Desk-Top, none of the "keys" (or whatever they are called) show-up on the 'Desktop', does anyone have any ideas as to why please?194.126.80.63 (talk) 00:45, 9 December 2017 (UTC)
 * I know very little about Macs and I am not sure what you mean when you say "keys", but I think that if you (for example) connect an external hard drive to that USB hub the drive will show up on the desktop, but the USB hub itself does not. Its just a bunch of empty extra USB ports, and they are only displayed on the desktop if you connect something to them. &#40;&#40;&#40;The Quixotic Potato&#41;&#41;&#41; (talk) 00:54, 9 December 2017 (UTC)
 * I know a bit more about Macs, and your understanding is correct. Also, not all hard drives can be powered via USB, not even via a powered hub - for most 3.5" drives, you still need an external power supply, or they won't turn on (and won't show up). --Stephan Schulz (talk) 00:59, 9 December 2017 (UTC)

Thanks for this, but each of the connections on the Hub have a portable programme 'key' plugged in and it is those that I should expect to show up on the "Desktop". Sorry not to remember what these portable "keys" are properly called! (Memory Stick is it?) — Preceding unsigned comment added by 194.126.80.63 (talk) 07:28, 9 December 2017 (UTC)
 * Each USB flash drive should show up as a separate drive on the desktop. If they are not showing after a short delay then perhaps there is a faulty connection somewhere?    D b f i r s   08:22, 9 December 2017 (UTC)
 * Can you try connecting your keyboard or mouse to the USB hub? After a few seconds delay the keyboard LEDs will come on, and the mouse's LED will come on (assuming it's on optical mouse). LongHairedFop (talk) 11:33, 9 December 2017 (UTC)
 * In addition to what LongHairedFop has suggested, you should also try plugging these "keys" into the exact same port the hub is plugged into and make sure they all work. Nil Einne (talk) 12:14, 9 December 2017 (UTC)

Thanks again, yes all the Memory Sticks work independently when connected into the computor, but don't work when reinstalled into the 'Cerulian' Hub. The Power Light is 'on' on the hub so it is not a power problem.;just weird! — Preceding unsigned comment added by 194.126.80.63 (talk) 15:53, 9 December 2017 (UTC)
 * So you did try the hub with something else like a keyboard or mouse and this worked? If so, final question, did you try with only one stick plugged into the hub? Nil Einne (talk) 06:51, 10 December 2017 (UTC)

Yes, and the individual Memory Sticks when plugged directly into the computor backside, work fine, but not when put into the Hub. — Preceding unsigned comment added by 194.126.80.63 (talk) 07:49, 10 December 2017 (UTC)
 * Does your hub work with any other devices (such as keyboard or mouse)? Have you tried it on a different computer?    D b f i r s   15:43, 10 December 2017 (UTC)

I do not have access to another compute194.126.80.63 (talk) 07:52, 11 December 2017 (UTC)r unfortunately, and yes I tried with just one Memory Stick and that don't work either. I will give up I think and throw it out of the window. Many thanks for your interest.194.126.80.63 (talk) 07:52, 11 December 2017 (UTC)
 * You could take the hub to your local library and try it there. Have you tried your keyboard or mouse through the hub?    D b f i r s   08:06, 11 December 2017 (UTC)

No but thanks for the idea, but both keyboard and mouse work wirelessly. My local library would not welcome me I don't think!194.126.80.63 (talk) 10:42, 12 December 2017 (UTC)
 * Is there a dongle for keyboard or mouse? Try moving it to the hub. LongHairedFop (talk) 20:19, 12 December 2017 (UTC)

No,there is no dongle.194.126.80.63 (talk) 07:08, 13 December 2017 (UTC)

Optimum number of threads on BOINC Primegrid LLR
Doing LLR tests on BOINC's PrimeGrid project on an i7, what is the optinum number of threads to run on an i7? When eight threads are running, the estimated time remaining doesn't decrease much. (I asked over there and didn't get a reply.) Bubba73 You talkin' to me? 20:19, 9 December 2017 (UTC)
 * The optimal time in FPU intensive tasks is usually equal to the number of physical cores - 4 in this case. Ruslik_ Zero 20:50, 9 December 2017 (UTC)
 * Does this help? &#40;&#40;&#40;The Quixotic Potato&#41;&#41;&#41; (talk) 20:52, 9 December 2017 (UTC)


 * Yes, it does. Thanks to both of you! Bubba73 You talkin' to me? 21:24, 9 December 2017 (UTC)