Wikipedia:Reference desk/Archives/Computing/2013 April 10

= April 10 =

External HD hot and not spinning down
One of my four external drives is hot and not spinning down when not in use. Utilities that read S.M.A.R.T. data show it at 67-72C at various times, which is too hot. The others spin down, but not this one. Is there a way to tell it to spin down when not in use? Bubba73 You talkin' to me? 02:58, 10 April 2013 (UTC)


 * If you don’t mind all your disks spinning down after the same interval of not being used, you can try using Windows’ own power options. Otherwise, you might have to rely on random third party apps. ¦ Reisio (talk) 03:16, 10 April 2013 (UTC)


 * I don't want the internal drives spinning down. That temperature is cause for concern, isn't it?  Bubba73 You talkin' to me? 03:31, 10 April 2013 (UTC)


 * Yes, I think so. You can always remove the case and point a fan at it, then unplug the HD when not in use.  Not an elegant solution, but it should keep it alive at least long enough to copy anything vital off it. StuRat (talk) 03:38, 10 April 2013 (UTC)


 * Of the two links you gave, the HDDScan zip file doesn't have an executable file in it. HotSwap starts up but doesn't do anything.  Bubba73 You talkin' to me? 03:44, 10 April 2013 (UTC)


 * You could try sdparm or hdparm. ¦ Reisio (talk) 03:48, 10 April 2013 (UTC)


 * I contacted Seagate tech support. Bubba73 You talkin' to me? 04:46, 10 April 2013 (UTC)


 * I contacted Seagate a few months ago to RMA a dying disk within its warranty period. The whole process went like this:
 * I raised the ticket
 * They asked me to run their own SMART utility (because they don't trust third party tools)
 * That reported the same scary SMART data that other utilities already had (the disk had thousands of 0x05 reallocations)
 * They emailed me an RMA label. I had to package the thing myself and post it, at my expense, to their facility (which for Europe is adjacent to Schipol Airport)
 * Because the disk still had data on it, I bought a new disk, dd copied the dying disk to it, and the dd blanked the bad one. The trouble with modern disks is that they're so gigantic that those dd operations took about 11 hours.
 * On receipt, they confirmed the disk was indeed bad, and mailed me a reconditioned one of the same specification as the previous one. I think it took about 11 days from my sending the bad to receiving the good. They didn't reimburse me for the postage sending the bad drive.
 * -- Finlay McWalterჷTalk 10:45, 10 April 2013 (UTC)


 * BTW, this is the external drive that I was making the Carbonite mirror image to (see problems above). But Carbonite said that the external drive was not the problem.  (However, it might be.)  Bubba73 You talkin' to me? 03:46, 10 April 2013 (UTC)


 * The temperature would be a cause of concern if it's correct. While I haven't used that many external HDs, I have my doubts whether it is. That's a very high temperature for a HD even locked up on a sealed case with no airflow I have doubts it's likely to get that high unless perhaps your ambient temperature is 50 degrees C. It could easily be either a defective sensor or buggy software or firmware. Unfortunately since it's external I presume you can't open it up to feel the HD casing (while the sensor is internal, if it was really that high you should feel it to some extent as the temperature differential shouldn't be that high). What is the temperature reported when just powered up after being off for a long time? Edit: However I have found some other reports of similar temperatures although again it's unclear if the temperatures are correct. (The statement by the user that the transfer rate had dropped from 100MB/s to 60MB/s after about an hour doesn't exactly inspire confidence that they know what they're talking about. The transfer rate drop almost definitely has nothing to do with the temperature but the fact that the middle of the HD is slower then the beginning. In addition, it doesn't sound like they understood the importance of backups.) Nil Einne (talk) 05:56, 10 April 2013 (UTC)


 * Two separate programs reported those high temperatures and I could feel that it was hotter than the others. I could also feel that it was running and not spinning down.  Seagate tech support told me how to set it to spin down using their software. It was set to spin down after 15 minutes of inactivity, but it wasn't doing it.  I changed it to 3 minutes and it is doing it. Now it is showing 47C. Bubba73 You talkin' to me? 15:35, 10 April 2013 (UTC)


 * Good. Those symptoms make me think that there is just some disk activity every 10 minutes or so, causing it to never hit the 15 minute threshold.  This would be most likely if this is the drive containing the active operating system.  However, that temp seems too high even when it is running, so I think you've just found a workaround, not actually fixed the problem.  I'd still want to remove the case to limit heat damage.  StuRat (talk) 15:59, 10 April 2013 (UTC)


 * Right now CrystalDiskInfo is showing it at 46C and my other external drives at 44C, so that seems OK. The internal drives are cooler, at 35 & 38C.  I think somewhere around 53-55C is considered too hot.  Bubba73 You talkin' to me? 16:17, 10 April 2013 (UTC)


 * Yes, but if you start using the drive, say to copy lots of files, I bet it will heat up to the danger zone again. StuRat (talk) 16:48, 10 April 2013 (UTC)


 * Yes, something isn't right. I set it to spin down, and that did work.  But later I noticed that it was spinning again.  After about a half hour of inactivity, it is still spinning and now the temp is up to 54C and in the yellow zone.  I'm going to try to track it down and see if it is something wrong with the drive or something about using it for the Carbonite mirror image, although I've had that turned off since yesterday. Bubba73 You talkin' to me? 17:33, 10 April 2013 (UTC)


 * some sort of indexing for windows or another search function? Gzuckier (talk) 18:55, 10 April 2013 (UTC)


 * Possibly, but I have indexing off except for my C drive. I believe the drive is defective.  I have another Seagate external, and running it continuously gets it no hotter than 45C.  Bubba73 You talkin' to me? 19:20, 10 April 2013 (UTC)

Why didn't Google's Street View service cover all streets in Kansas like they did in so many other states?
Look here, there are only 2 or 3 streets in Concordia, Kansas that Street View covers. However, in many other places in the US, all streets are.

Why did Google's Street View fleet get neglectful in Kansas?

Moreover, was that a one-time project or will they send out another fleet of Street View cars in order to cover the roads that they didn't the first time? Is there any way to know whether they will come around Kansas again to map the streets that they didn't earlier? Thanks. --70.179.161.230 (talk) 07:12, 10 April 2013 (UTC)


 * [] has the answer. It doesn't cover all the US yet. OsmanRF34 (talk) 11:45, 10 April 2013 (UTC)


 * They probably prioritized places people would be more likely to actually want a street view of. I know they’ve been by my own house two or three times over the years already, though, so it doesn’t really make complete sense that they haven’t been by all those. I imagine that’s all contract work, though, so however much interest/personnel are available for it in whatever location is probably a factor. They could also already have all the data but for whatever reason haven’t incorporated it yet. ¦ Reisio (talk) 14:44, 10 April 2013 (UTC)

Optical disc drive no longer reads DVDs of any kind but can still read CDs
I have a Windows XP computer with an internal optical disc drive (it's a DVD-RAM drive made by LG). Up until very recently, it was able to read and write to both CDs and DVDs, but I noticed yesterday that it is no longer able to read DVD media of any kind (video or data). It can still read CDs, but after a DVD has been inserted (and removed) it is no longer able to read a CD until the computer is restarted (which seems odd if it's a hardware problem).

Should I just buy a new disc drive or is this behaviour potentially linked to a software problem? The drive in question is at least five years old at this point and new drives are cheap, but I'd rather not throw the old drive away unless necessary. Any comments would be appreciated. 142.20.133.199 (talk) 13:43, 10 April 2013 (UTC)


 * If you can boot from USB (or another CD/DVD drive on the same box), you could boot up a live OS and try to play with the drive in question, potentially ruling out a hardware issue (or confirming one). ¦ Reisio (talk) 15:03, 10 April 2013 (UTC)


 * It could very well be a hardware issue, since bits are more closely packed on a DVD than a CD. Therefore, if it's accuracy is off a little bit, it will miss the DVD bits, but still find the CD bits.  You might try a CD cleaner, in case some schmutz on the read head is the problem. StuRat (talk) 17:42, 10 April 2013 (UTC)
 * CD and DVD drives use different laser diodes. Probably the laser diode that is needed to read/write DVDs stopped working. Ruslik_ Zero 18:52, 10 April 2013 (UTC)

Virus causing password requirement?
Is there a virus that affects Windows 7 that causes the computer to require an administrative password to start it? (It's my computer-illiterate mother's computer, not mine, mind you, so "lrn2linux" comments to /dev/null.) If so, and if it changes the admin password, what would it change it to? — Jeremy  v^_^v  Bori! 18:38, 10 April 2013 (UTC)


 * It may be Ransomware (malware). -- Finlay McWalterჷTalk 18:51, 10 April 2013 (UTC)
 * It isn't giving a number or any other means to contact. All it's doing is asking for a password to boot into Windows. — Jeremy  v^_^v  Bori! 18:52, 10 April 2013 (UTC)
 * Isn't that the usual behavior of Windows 7? Could you give a clearer description of exactly what you are seeing? Looie496 (talk) 18:59, 10 April 2013 (UTC)
 * When one attempts to boot up, a window pops up which indicates that a password is needed to finish booting up the OS. (i.e. it doesn't go into the login screen.) As my mother is computer illiterate, this isn't something she would have been able to set up herself. It gives you three attempts at the password before it restarts. — Jeremy  v^_^v  Bori! 19:01, 10 April 2013 (UTC)
 * Could you say what model of computer it is, and the exact wording of the text you see? I'm trying to figure out whether this is a BIOS password or something else. Looie496 (talk) 19:21, 10 April 2013 (UTC)
 * It is a Dell Inspiron desktop (model number escapes me), and the text of the box is "This computer is configured to require a password in order to start up. Enter the Startup Password below." — Jeremy  v^_^v  Bori! 19:25, 10 April 2013 (UTC)
 * On a similar note, the administrator password is not set up in the BIOS, so it's not BIOS-related. — Jeremy  v^_^v  Bori! 19:33, 10 April 2013 (UTC)
 * A search for those messages shows nothing relating to Windows 7 but numerous reports involving Windows XP. Apparently it is possible to set up XP to require a System Password, but there is also malware that does it.  If it is malware, probably the only solution is to restore the system. Looie496 (talk) 19:54, 10 April 2013 (UTC)
 * Okay, and how would I go about doing that if I can't even access the operating system? — Jeremy  v^_^v  Bori! 19:58, 10 April 2013 (UTC)
 * You need to have a disk you can boot from. If you don't have a system restore disk, things become challenging.  Is this actually perhaps XP, by the way? Looie496 (talk) 20:02, 10 April 2013 (UTC)
 * No, it's Win7. Not XP. — Jeremy  v^_^v  Bori! 20:05, 10 April 2013 (UTC)


 * You may need to take it to an electronics place like Best Buy or something similar, where they will have boot disks, if you don't have one, and reset the password. RNealK (talk) 22:24, 10 April 2013 (UTC)

Downgrading Windows 7 from 64-bit to 32-bit
As far as I can tell, 64-bit Windows 7 does nothing useful for me, and just hogs a lot of memory. So, if I wanted to switch back to 32-bit, would I have to uninstall and reinstall the O/S, then reinstall every app for it ? Or can I just set a flag somewhere to have to work in 32-bit mode ? StuRat (talk) 18:55, 10 April 2013 (UTC)


 * You’d have to reinstall. I suggest you don’t (unless to switch to a better OS! :p). ¦ Reisio (talk) 19:07, 10 April 2013 (UTC)


 * I wouldn't do it either. The 64-bit Windows manages your memory better, for one thing.  For instance, if you have 4GB of RAM, I think 32-bit Windows only has access to 3 to 3.5GB of it whereas 64-bit Windows gets all of it.  Someone correct me if I'm wrong. (And some software functions better in the 64-bit version.)  Bubba73 You talkin' to me? 19:15, 10 April 2013 (UTC)


 * Yes, but I only have 2GB of RAM, and it seems pegged out near 100% all the time under 64-bit mode, while that should be plenty for 32-bit.


 * What software functions better in 64-bit mode ? StuRat (talk) 19:42, 10 April 2013 (UTC)


 * Theoretically anything available as 64-bit builds; realistically, ATM, in measurements you might actually care about: more server-oriented software. ¦ Reisio (talk) 20:03, 10 April 2013 (UTC)


 * You will have to reinstall to go 64->32. 2Gb is the very bottom end of MicroSoft's stated requirements for Windows7/64 (ref), with 1Gb for WIndows7/32. If you can at all manage it, new memory is almost certainly cheaper than your time. -- Finlay McWalterჷTalk 21:19, 10 April 2013 (UTC)


 * Yes, going up to at least 4GB is a lot better way to go. Except for one laptop with only 2GB, I've had 4GB in every machine that would take it, going back years.  I now have 16GB.  The 32-bit Windows maxes out at 3-3.5GB, depending on your system.  I think 4GB per CPU is a good figure. Bubba73 You talkin' to me? 23:09, 10 April 2013 (UTC)


 * I'm not really convinced. 64-bit mode apparently doubles the memory requirements, yet offers very little in return, except for the ability to use the extra memory which it requires.  To me that's like saying "Get the Chevy Suburban !  Sure, it burns twice as much gasoline, but you need to get it for the gas tank, which is twice the size !" StuRat (talk) 00:37, 11 April 2013 (UTC)


 * If your computer can handle 4GB of RAM and it has open slots, you can add 2GB from Crucial.com for under $40. If you have to pull out the memory you have to go up to 4GB, you can do it for about $72.  I recommend going up to 4GB, at least.  Look at it this way: MS says the 32-bit version needs 1GB and the 64-bit version needs 2GB.  If you only have 2GB, you need more for your apps.  The more memory you have, the better performance.  Also, consider with 2GB and the 32-bit version taking 1GB, that leaves only 1GB for your apps (and disc cache).  With the 64-bit version and 4GB of RAM, you have 2GB for your apps.  Bubba73 You talkin' to me? 00:59, 11 April 2013 (UTC)


 * But don't 64-bit apps also require twice as much memory ? StuRat (talk) 06:31, 11 April 2013 (UTC)


 * Is your computer actually running like it is under memory pressure? Just because you are near the limit doesn't mean that it is actively using all that memory, and it can probably effortlessly swap out big chunks of it when there is a demand for more use. It might just be making good use of all your memory, making sure that the programs your using are using as much physical memory as possible. Of course, if your drive is constantly going crazy managing your swap, then you need to do something about it, but I'm just pointing out that high memory usage isn't alway a symptom of not having enough RAM. I had 4GB system at home that always ran near the limit, but it suffered no obvious performance hit when I borrowed 2GB of the RAM for another system.
 * Also, 64-bit apps don't take twice as much memory, the instructions and data are all the same size except for pointers, which will be 64-bit. 38.111.64.107 (talk) 12:00, 11 April 2013 (UTC)


 * Yes, it has lots of lag, presumably when swapping memory in and out of paging space. StuRat (talk) 16:14, 11 April 2013 (UTC)


 * Right, 64-bit programs don't require twice as much memory. As he says, pointers are 64 bits instead of 32.  But for integers, the programmer has a choice of 64, 32, 16, or 8 bits.  In the programming system I use, 32 bits is still the default for an integer, so the programmer doesn't normally use a 64-bit integer, unless it is needed.  Bubba73 You talkin' to me? 15:20, 11 April 2013 (UTC)


 * So then, why exactly are the memory requirements for the 64-bit version of Win 7 twice that of the 32-bit version ? Does the 64-bit version use only the first 32 bits of every pointer, wasting the other 32 bits, at least until I go past 3 or 3.5 GB of RAM ? StuRat (talk) 16:14, 11 April 2013 (UTC)


 * The first part - I don't really know, but Microsoft recommends 2GB minimum for 64-bit and 1GB for 32-bit, but I don't know if it really takes twice as much. (It might be that 1GB simply isn't enough for 64-bit, so 2GB is the next larger size.)  Second part, as far as I know, in 64-bit software, all pointers are 64 bits, even if only 32 bits are required.  That does waste some memory, but really not that much since it applies only to pointers.  And if you do have access to the additional memory, it can make things run a lot more efficiently.  (Whether or not it actually does depends.  In my tests, 64-bit programs run a little slower than their 32-bit counterparts unless they specifically take advantage of the 64-bit stuff - then they are substantially faster.)  Bubba73 You talkin' to me? 16:25, 11 April 2013 (UTC)


 * It doesn't sound like the 64-bit implementation is very good. I'd have expected all the pointers to continue to be 32 bits (or even less), except where the software can actually gain some advantage by using 64 bits.  To do otherwise seems as inefficient a use of memory as if I wrote my programs with all double word reals, regardless of what precision is actually needed. StuRat (talk) 04:40, 12 April 2013 (UTC)


 * I'm not very knowledgeable about this, but having 64-bit pointers allows the data the which it is pointing to be anywhere in the address space. I think that would allow it to run anywhere in the memory of machines that have more than 4GB of memory.  (Someone correct me if this is wrong.) We has 32-bit pointers long before PCs had 2GB or more of RAM.  A 64-bit pointer might be pointing to thousands, millions, or billions of bytes of data, so the extra four bytes for the pointer is negligible.  Bubba73 You talkin' to me? 04:59, 12 April 2013 (UTC)


 * I would expect logic like this (assuming 8 bit bytes) to fire up when the O/S boots:

if    (RAM > 2^32) then POINTER_SIZE = 40 elseif (RAM > 2^24) then POINTER_SIZE = 32 elseif (RAM > 2^16) then POINTER_SIZE = 24 elseif (RAM > 2^8) then POINTER_SIZE = 16 else POINTER_SIZE = 8


 * Is there some reason operating systems can't do that ?


 * Also, 64 bits seems rather excessive, as that allows for some 2^64 or 18.4 million TB. I don't see us getting PCs with that much RAM anytime soon.  40 bits allows for over one TB of RAM, which should be sufficient for the time being. StuRat (talk) 19:11, 12 April 2013 (UTC)


 * I'm also pretty sure that we will never have 264 bytes of RAM. But the path to memory is 64 bits wide, so it might as well get 64 bits.  Also, the size of the pointer is embedded (hard coded) in the software.  Bubba73 You talkin' to me? 01:51, 13 April 2013 (UTC)


 * Back to 32- vs. 64-bit programs - just about all modern chess engines for Windows have 32- and 64-bit versions, and the 64-bit versions are somewhat stronger - clearly enough stronger to make it worthwhile. Bubba73 You talkin' to me? 02:45, 13 April 2013 (UTC)

Person of Interest (TV series)
In Person of Interest (TV series), there is a Machine, which monitors global communications, CCTV, etc, to determine terrorist threats, as well as premedidated murders. My question is, how feasible is this in real life. How much space would it take? -mattbuck (Talk) 20:56, 10 April 2013 (UTC)


 * It already exists. The National Security Agency runs it, in the US.  It's not a single machine, but many.  Of course, it can't actually predict the future, as it does in the show.  I believe part of the set-up for that show is that there is info the NSA isn't concerned with, like potential murders, as that's not their job.  This is why it gets farmed out to the characters on that show, supposedly, to do something about it.  (In the show, they might call it the "CIA", instead of "NSA", as people are more familiar with the CIA.  The NSA has done an excellent job of keeping a low profile.) StuRat (talk) 20:59, 10 April 2013 (UTC)
 * Are you talking about Echelon? Note that our article is full of "citation needed", and the more "reliable" refs are full of speculation. Nobody really knows what Echelon can or cannot do. But it probably cannot monitor CCTV mentioned by the OP (assuming wired, no broadcast), and it probably cannot read your email if you use PGP. SemanticMantis (talk) 21:12, 10 April 2013 (UTC)


 * Outside of acquiring the cameras and access to all communications, etc., the bottleneck isn’t space or hardware, but software, and just having a large set of data to infer from. ¦ Reisio (talk) 21:09, 10 April 2013 (UTC)


 * Communications: ECHELON sending data to Trailblazer. In some countries automatic number plate recognition is centralised too. Some CCTV is centralised, much isn't. I doubt there's much real-time facial recognition yet, but it's a mostly solved problem, so the problem of integrating that with centralised CCTV and harvesting the result (being able to track a given person as they walk around a city) is a problem of organisation, scale, and legality (not really technology). TV, as usual, follows precedes reality (except for those curious blips that TV graphics still make, even though real computers stopped doing that in about 1980). We're not quite in the panopticon yet. The NSA article StuRat linked makes some statements about budgets and real estate, from which you can infer something of the scale of current efforts. -- Finlay McWalterჷTalk 21:14, 10 April 2013 (UTC)


 * Also relevant is Carnivore_(software). SemanticMantis (talk) 22:31, 10 April 2013 (UTC)

text files older than 10 minutes
From the command line on Windows I need to scan a directory for .txt files that are older than 10 minutes and execute a program if any are found. I have most of the common unix programs available to use. Thank you for your help. 92.233.64.26 (talk) 23:56, 10 April 2013 (UTC)


 * I think this will work, but I haven't tested it. It should find all files with .txt in the current directory that have not been modified in the past 10 minutes. For each of those files it will run FOO.   find . -name "*.txt"  -depth 1 -mtime 10 m -exec FOO {} \;   RudolfRed (talk) 01:19, 11 April 2013 (UTC)
 * Minor fix for the modification time: I suppose for -depth 1 you meant -maxdepth 1 ; I don't know if that restriction (to files contained directly) is desired. For brevity, you can use \*.txt (on Windows, I believe you needn't quote the pattern at all); on modern versions of find you can omit the . for the working directory.  --Tardis (talk) 13:52, 11 April 2013 (UTC)
 * Thanks for the corrections. It depends on which version of "unix programs" the OP is using.  I was reading the man page for BSD find when I wrote my answer.  GNU find has the syntax you suggested.  RudolfRed (talk) 15:57, 11 April 2013 (UTC)

Thanks 92.233.64.26 (talk) 15:29, 11 April 2013 (UTC)