Wikipedia:Reference desk/Archives/Computing/2013 June 9

= June 9 =

Identities
I look at a blog page, and scroll down to "comments", and it says "Sign in with", and there follow the logos of, among others, facebook, twitter, and google. I click on google. I enter my login information. Then it says "Post as X", but intstead of my name, it was my wife's name where the "X" appears. I log out, then try the same with facebook. Same result. This was on a home computer used by both of us. But last week I got the same result on an on-campus computer never before used by either of us. I've spent the past two hours trying to figure out how to correct this, in particular looking through some of google's pages. No luck. What's going on and what can be done about it? Michael Hardy (talk) 01:04, 9 June 2013 (UTC)

Computer crash (beep + black screen + computer comes back with no sound)
Recently having issues with my computer since ever I started gaming once again. Basically a black screen crash happens followed by a "beep" from my computer, but the screen comes back thereafter, but with no sound. I cleaned the insides a few days ago, so I don't think that it's an overheating issue. 40 celcius doesn't seem that high to me, my old rig frequently topped 60s without crashing; maybe the BIOS has a low threshold before it launches a protective measure?

Specs taken from Speecy shortly after an occurrence: 24.201.128.254 (talk) 03:30, 9 June 2013 (UTC)
 * Microsoft Windows 7 Home Premium 64-bit SP1
 * Intel Core i7 3770 @ 3.40GHz	37 °C Ivy Bridge 22nm Technology
 * 16,0GB Dual-Channel DDR3 @ 733MHz (11-11-11-28)
 * ASUSTeK COMPUTER INC. CM6870 (LGA1155)	36 °C
 * ASUS VH242H (1920x1080@60Hz) 2048MB GeForce GTX 660 (EVGA)	40 °C
 * 233GB Samsung SSD 840 Series ATA Device (SSD)	36 °C
 * 1863GB Seagate ST2000DL003-9VT166 ATA Device (SATA)	42 °C
 * ATAPI BD E DH12E3SH ATA Devic
 * NVIDIA High Definition Audio
 * PSU ROSEWILL|RX750-S-B 750W RT


 * The no sound makes me wonder if there's a problem with the speakers. Does it have external or internal speakers ? Are there any other problems with the sound, like static ? StuRat (talk) 15:00, 9 June 2013 (UTC)


 * I agree with StuRat's notion that it's probably a speaker problem. I believe I had this same (or similar) problem on an XP machine a few years back. What do you do to get the sound back? IIRC all I had to do was a reboot. --Yellow1996 (talk) 17:27, 9 June 2013 (UTC)

The sound comes from the monitor, which is an ASUS VH236H 23-Inch Full-HD LCD. — Preceding unsigned comment added by 24.201.128.254 (talk) 21:39, 9 June 2013 (UTC)


 * I wondered about that. I suspect the problem is actually in your monitor, not in your computer.  LCD monitors can be pretty flaky beasts sometimes.  Are you sure you've connected the audio from your computer to the monitor properly? Looie496 (talk) 14:03, 10 June 2013 (UTC)

It's a single HDMI cable that feeds both the audio and the video. Maybe that's the source of the problem? I just switched it with the one of my PS3 (higher quality), just to try. 24.201.128.254 (talk) 21:53, 10 June 2013 (UTC)


 * So, did the PS3 cable fix the problem? --Yellow1996 (talk) 01:21, 11 June 2013 (UTC)

No idea, only ever happens when I play games. 24.201.128.254 (talk) 03:13, 11 June 2013 (UTC)


 * Maybe not the cable itself, but an intermittent connection at one end. Does the cable appear loose at either end ? StuRat (talk) 03:21, 11 June 2013 (UTC)

Just crashed on me. I don't think it's the connection, otherwise it would happen outside of games. Eisenikov (talk) 18:15, 11 June 2013 (UTC)

Could it be because the monitor is running under Nvidia drivers, and my headset on Realtek, and there's somehow a conflict? On a side note, I just ran Windows Memory Diagnostic and nothing came up. Eisenikov (talk) 18:28, 11 June 2013 (UTC)


 * It could be; but I think it could still be a connection issue. Maybe it only triggers a crash when playing games because it's heavier on the connection? Just a guess, though. Also, strange about the WMD. --Yellow1996 (talk) 01:20, 12 June 2013 (UTC)

I just ordered a pair of Z623s, we'll see if it's an audio issue. Eisenikov (talk) 21:32, 12 June 2013 (UTC)

I ran memtest+ and it found nothing after three passes. I also reinstalled my Nvidia drivers, and so far after three hours of gaming, there was no crash. Eisenikov (talk) 20:03, 13 June 2013 (UTC)


 * That's good to hear. Hopefully the driver reinstallation has fixed the problem. --Yellow1996 (talk) 01:26, 15 June 2013 (UTC)

How can I download a book from Google books?
I am neither able to preview the full book nor download the book from Google books. How can I download a book from Google books? 106.212.100.220 (talk) 11:47, 9 June 2013 (UTC)
 * If you can't preview the whole book, you will not be able to download it for free. Depending on the book, you might be able to buy an electronic version of it from Google Play or another source. Looie496 (talk) 14:11, 9 June 2013 (UTC)

Use and abuse of open source software
If open source software is so amazing, why are companies still able to sell software? I mean not maintenance contracts or consulting or customization, but software as such. And second, being open source, doesn't mean that anyone can adapt it maliciously too? OsmanRF34 (talk) 13:18, 9 June 2013 (UTC)
 * Lots of commercial software is superior to open source equivalents, because the developers, knowing that they can make money if the software works well, put more effort into it. Also the customer support for commercial software is generally superior.  Regarding malicious changes, that can certainly happen, but most open source software is distributed in the form of source code rather than precompiled binaries, so malicious changes are hard to conceal. Looie496 (talk) 14:09, 9 June 2013 (UTC)


 * Exactly. Also; being the big companies that they (usually) are, they can have a very big budget on their software projects, often yielding better results than the open source equivalents. --Yellow1996 (talk) 17:31, 9 June 2013 (UTC)


 * Also, many companies offer very specific and specialized software of which there are simply no open source equivalents available. 77.101.52.130 (talk) 17:34, 9 June 2013 (UTC)


 * From the buyer perspective, for big companies/government agencies where software cost is not a big issue going with the well known commercial software might be an easier, less risky (in the view of the decision maker) choice than some unknown/obscure (in view of decision maker) open source equivalent, even if it is equal or superior. Also people being used to a certain software product might be reluctant to learn a different product. Also compatibility issues could be relevant (sometimes created by the producers of commercial software themselves; who make it unnecessarily difficult for open source programmers to copy the commercial product). bamse (talk) 21:14, 9 June 2013 (UTC)


 * “If open source software is so amazing, why are companies still able to sell software?”
 * Mass ignorance. Give it time. ¦ Reisio (talk) 18:23, 10 June 2013 (UTC)


 * It's not an all-or-nothing situation. Open source software can be great, and useful, and successful, without completely eliminating for-profit closed source products. For instance, open source browsers have absolutely displaced closed source browsers over the past several years . Another great example of displacement is supercomputer OS, see the graph at Usage_share_of_operating_systems. Recently, there has been much discussion of Adobe's proposed subscription model, and several smaller companies will likely switch to free/open source alternatives. Just google those terms if you want to read more about that. (p.s. I added some indentation to previous answers to make things more readable/clear) SemanticMantis (talk) 19:54, 10 June 2013 (UTC)


 * Some niches are dominated by FOSS:
 * Image processing (GIMP, although "photoshopped" sounds better than GIMPed)
 * Fractal calculation (FractInt, until UltraFractal came up and demonstrated "superior performance" (on a Pentium II compared to FractInt on a 386SX)... to be fair it should be mentioned that UF is more user-friendly (a point which FOSS is usually lacking), and Chaos Pro as a free UF clone is gaining on UF
 * As already mentioned, browsers in general
 * LAMP (Linux, Apache, MySQL, PHP), another package which is heavy on networking (web server)
 * But, even without malicious changes, commercial software is more standardized. There may be a new standard every ~3 years (Word 95/97/2k/2k3/2k7) but at least not with each major recompile. You don't have anyone's word that one build can even read the other build's files, an issue which can at the worst case kill your business. 217.255.154.201 (talk) 06:59, 13 June 2013 (UTC)
 * There's also the network effect - sometimes somethings remain popular just because they are popular. For instance, because Microsoft Office is the most popular office suite by a long way, many people will buy it simply because they already use it elsewhere and are used to it, exchange files in its file-format, etc.  None of these things are insurmountable, but sometimes its easier to just go with the flow.   d avid p rior  t/c 17:42, 13 June 2013 (UTC)

Blogs?
I want to have another go at keeping a blog, but as things are, I have a wide range of different interests, and truth is, I find some of them just a little embarassing, at least around people that aren't into the same thing, I am tempted to post details on all of them to the same blog, and arrange them with categories and tags, but I am not sure, a little nervous about how it would go. on the other hand, I doubt I would have enough worth saying to maintain a decent blog on each separate topic. any ideas what else I could do? Also, suppose I created separate blogs under the same username, how easy would it be for readers of one to find the others?

213.104.128.16 (talk) 15:17, 9 June 2013 (UTC)


 * Readers will easily be able to find the others if you make use of a magical device known as a "link". Regarding the rest, it's not our function here to give advice. Looie496 (talk) 15:32, 9 June 2013 (UTC)


 * ok, fair enough. what if I don't want them to find the others, do blog sites automatically link blogs by the same creator anywhere? 213.104.128.16 (talk) 15:39, 9 June 2013 (UTC)


 * If you use the same screen name, I bet people can find your other posts, yes. I suggest a different screen name for the embarrassing posts or, even better, a different screen name at a different blog site.  There might still be a way to track them down using your I/P address, but that seems unlikely. StuRat (talk) 15:53, 9 June 2013 (UTC)


 * ah, ok. though, it's not so much that I never want anyone to see them, it's nothing serious, just would rather minimise the number of people that stumble onto them by accident 213.104.128.16 (talk) —Preceding undated comment added 15:59, 9 June 2013 (UTC)


 * Then you should definitely use a different screen name (or, better yet, a different blog hosting service) for each blog. Or, if you want things easier to manage, you could just pick the topic/interest you think you could write the most about then only do a blog on that; but it's completely up to you. Good luck! --Yellow1996 (talk) 17:36, 9 June 2013 (UTC)


 * Try an 80/20 rule. Make a list of all the topics you want to write about. Pick one for your Big Topic that will be 80% of your posts. Then pick a Small Topic or collection of smaller topics that will comprise the remaining 20%. Try to have a small topic that pairs with the big topic, so fans of your 80% topic are not scared off by the other stuff. For example, science and technology, law and politics, food and wine, but not sex and birdwatching (although I would like to see such a blog). If you have too many topics that don't pair well together, break them into separate blogs following the same pattern. It's up to you whether you link between them. Fletcher (talk) 19:52, 10 June 2013 (UTC)

How to add blacklist to Gmail ?
That is, how do I create a list of addresses which I want to block from sending me email ? StuRat (talk) 15:49, 9 June 2013 (UTC)


 * I believe all you can do is create a filter that deletes anything received from those addresses.
 * Click on the "cog" button and select "settings". Click on the "Filters" tab.  At the bottom, select "create new filter".  Add the unwanted addresses into the form.  Click on "Create filter from this search" and in the actions list select "Delete".  Rojomoke (talk) 17:20, 9 June 2013 (UTC)


 * You can use and operators in the from line (I think there are instructions for making complicated rules, but if I remember right they're hard to find in the google help) so you could combine a lot of blacklisted addresses into one. I assume there's some limit on the filters so you might need multiple ones. Shadowjams (talk) 18:38, 9 June 2013 (UTC)


 * Stu, I do the above filter thing with my Gmail. My school's faculty thinks nothing of sending everyone in the school an email about everything from class registration reminders to intramural team sports to lost calculators. So most of the school faculty is blacklisted in Gmail by creating a filter as advised above.  You can create one filter and just separate all the email addresses with OR, e.g. Billy@kidd.com OR Casandra@chimera.org OR Salma@hollywood.gov.  Dismas |(talk) 06:11, 10 June 2013 (UTC)

Thanks all. The filter works as you described, so now I know how to add a blacklist to Gmail ! StuRat (talk) 03:12, 11 June 2013 (UTC)

YouTube Downloader (yeah, I know...)
I know I've probably read this 1,000,000,000,000 times in the archives, but I cannot remember any names; and I would like to know what the current popular tools are. So my question is: what is the best (no spyware/adware/scareware/spammy/etc) way to download videos off of YouTube (for archival purposes, of course.) Thanks! --Yellow1996 (talk) 18:01, 9 June 2013 (UTC)
 * I think the most popular way to do that is by installing RealPlayer, which gives you download links on Youtube videos. Looie496 (talk) 18:26, 9 June 2013 (UTC)


 * Thanks for the quick response, Looie. I'll keep that in mind, though I'd rather not have to install yet another media player! (I have too many...) I'm also open to FireFox addons even though I'm an IE user. --Yellow1996 (talk) 18:34, 9 June 2013 (UTC)


 * Firefox extensions DownloadHelper and NetVideoHunter will do it, as will VLC media player and the command line youtube-dl program. -- Finlay McWalterჷTalk 18:40, 9 June 2013 (UTC)


 * Cool! I have VLC! :) And I'll also check out those extensions; thanks so much, Finlay! :) --Yellow1996 (talk) 18:42, 9 June 2013 (UTC)


 * It (DownloadHelper) worked perfectly!!! Thanks again! :) --Yellow1996 (talk) 18:58, 9 June 2013 (UTC)
 * If you have Java and are willing and able to run a Java applet there are plenty of popular websites like KeepVid . Nil Einne (talk) 20:20, 9 June 2013 (UTC)
 * This is off topic, but you should disable Java in the browser if you can, since its security model is broken and basically unfixable; see Java (software platform). At the least you should run something like NoScript in whitelist mode and only allow Java applets that you trust. -- BenRG 06:05, 10 June 2013 (UTC)


 * Well, I'm primarily an IE user, so NoScript isn't really an option. I don't know if I have Java disabled or not - I remember hearing about all the security holes so I started denying the updates quite a while ago...but how would I check to see if I have it disabled? --Yellow1996 (talk) 01:25, 11 June 2013 (UTC)

JDownloader77.101.52.130 (talk) 22:02, 9 June 2013 (UTC)
 * We're going off topic here, but denying the updates is unequivocally the worst thing you could possibly do in response to worries about a security risk. Either disable it, or keep it up to date. Looie496 (talk) 02:00, 11 June 2013 (UTC)


 * Okay, I've disabled the Java extensions in IE. --Yellow1996 (talk) 01:22, 12 June 2013 (UTC)

RAM question
I upgraded my laptop to 16 GB memory, which it turns out is more than I needed. Often I have well over 8 GB free and zero page outs. Does this mean one of my RAM sticks is basically unused most of the time, or does the OS distribute data evenly throughout the available RAM? Thanks. — Preceding unsigned comment added by 98.110.138.92 (talk) 21:15, 9 June 2013 (UTC)


 * The correct answer to this question depends on many factors: the most important factors are the exact type of operating system, and the exact type of CPU (In 2013, most laptop memory controllers are integrated on the CPU) ; and in some cases, also depending on the type of RAM. "In general," the operating system is smart enough to allocate the RAM according to the "most efficient" method.
 * For example, if you have a 3rd-generation Intel Core CPU, and if your operating system is intelligent in its physical memory allocation, your CPU can power off some of your RAM and some of your CPU's logic to save energy (Intel 3rd Generation Core Data Sheet, §4.3 (IMC Power Management). If your operating system is cooperative and aware of this hardware's capabilities, chances are good that it allocates physical memory in consideration of such details.
 * In other cases, your operating systems may choose to allocate memory according to speed or performance optimizations; for maximum memory throughput performance or minimum cache-latency, or some other metrics, it is advantageous to strafe across multiple physical memory units. If so, your operating system will set up the memory controller to use both "sticks" of RAM, even when accessing contiguous virtual memory.
 * If you have a general purpose operating system, you will never see or worry about these details; the designer of the system will make the "best" choice(s) for you - balancing power, performance, stability, and anything else - according to what works best "for most users." Only very specialized operating systems expose these sorts of low-level details to the computer operator.  Nimur (talk) 22:13, 9 June 2013 (UTC)


 * Thanks. I'm running OS X on a Core i5. Knowing that I overbought, I was wondering if one of my sticks is a "benchwarmer", rarely used. Obviously a very complicated subject. That's an interesting point that memory could be dynamically powered down to save energy, didn't know that. 98.110.138.92 (talk) 22:22, 9 June 2013 (UTC)
 * I think what Nimur wrote is inaccurate. RAM can be put in a lower power state when the processor isn't reading or writing it, but it still holds its data during that time (section 4.3.2.3 of the document Nimur linked mentions that the DRAM refresh cycle still happens, and the purpose of that is to preserve the data).
 * All major OSes will use all of your RAM since there's no advantage to leaving it unused. Memory not needed for other purposes is either used for disk cache or pre-zeroed so that future allocation requests can be satisfied more quickly. Both of these improve performance to some extent, though you're probably in the zone of diminishing returns. -- BenRG 05:52, 10 June 2013 (UTC)
 * BenRG, exactly what did I write that you believe is inaccurate? If I misspoke or made an error on a specific detail, I would prefer to correct that detail.  But after reviewing my comments, I did not find any obvious error or inaccuracy.  Perhaps you are unfamiliar with the terminology used to describe DDR3 power management?  If so, I can point you towards some useful tech notes.   For example, here is Micron TN4615 on DDR3L.  And here is TN4714 on precharge powerdown for DDR2.  Here is a tutorial from Hynix on basic operation of SDRAM.  Here is the power statemachine for Samsung DDR memory.  I am not aware of any DDR device that performs self-refresh while clock enable is low.  This is the lowest power-state that a DDR3 device provides.
 * To be further specific, some Intel memory controllers also allow per-channel DLL control. On these devices, the memory is powered down and communication with the memory-part is terminated.  Do you have reason to believe data is preserved in the memory while the system is in this state?
 * The points I made above were fairly simple: an operating system can strategically manage memory and can shut down parts of the memory and memory controller - including all or part of a SODIMM, and if you need more complicated details on how this works, you can find them in these references. Nimur (talk) 06:46, 10 June 2013 (UTC)
 * See section 4.3.2.3 of the first document you linked, which says "If dynamic power down is enabled, all ranks are powered up before doing a refresh cycle and all ranks are powered down at the end of refresh." In principle you could stop refreshing the RAM and lose the data, but I don't think any major OS does so, at least on the standard PC architecture. It's more efficient to use all available RAM for disk cache because swapping is so expensive. I did find this page about new support for memory power management in Linux in mid-2011, but I don't think it's talking about PCs (one of the comments says there's no way to do it on x86). -- BenRG 08:54, 10 June 2013 (UTC)
 * Perhaps you are confused as you are repeatedly quoting §4.3.2.3: dynamic power down - one specific mode of operation - is a description of only one possible mode - it is not a general description of every other power management mode.  You're quoting one sentence describing one power-mode in one processor-family datasheet.  If you read elsewhere in the same datasheet and any of the other links I provided, you'll find descriptions of different power management modes.  The first line of the first reterence I provided: "The main memory is power managed during normal operation and in low-power ACPI Cx states."  The rest of the section describes each other type of power-saving available on this particular platform.  Several of these memory power management modes, including active power-down, and pre-charge power-down, and DLL power-down, can be used while the processor is active (in C0).  As described above, in such modes, the memory is not refreshed when CKE is low.  Nimur (talk) 15:11, 10 June 2013 (UTC)