Wikipedia:Reference desk/Archives/Computing/2009 July 30

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July 30[edit]

Compressed HTTP[edit]

In compressed HTTP, can transmission begin while compression is still in progress, and can decompression begin while downloading is still in progress? If so, what software actually does this? NeonMerlin 00:31, 30 July 2009 (UTC)

HTTP compression - yes and yes, sort of. It's not actually separate software, exactly, that does the compression/decompression. It's usually just a built-in feature, although it might be a specific library or plugin that the browser/server uses. Instead of compressing the files, then sending the compressed file, it usually gets streamed to the compression module which compresses it, then sent over the internet, received by the browser, which streams the compressed data to the decompressing module as it receives it, which then streams the uncompressed data to the rest of the browser. AFAIK. The links in the http compression article might help more. Indeterminate (talk) 01:35, 30 July 2009 (UTC)

difference between core 2 duo and dual core[edit]

Could anyone explain to me in what way core 2 duo processor is different from a dual core processor ? srini 05:02, 30 July 2009 (UTC) —Preceding unsigned comment added by Srini279 (talkcontribs)

Bear with me - there is some confusing terminology here. Intel has released CPUs under the brand names "Core 2 Duo" and "Dual-Core". "Dual core" can also be a generic technical description, which has nothing to do with the brand-name.
The term "dual core" can mean any system that has two CPU cores. A CPU "core" is the basic instruction processing pipe - so two cores means that the CPU can simultaneously process two instructions in the same clock cycle (rather, it has an entirely duplicated instruction pipeline, including fetch, decode, and execution logic). "Intel Core" is also a brand-name for a certain microarchitecture, designed by Intel. "Dual Core" refers to the brand name of certain Intel CPUs that use that architecture. The Core 2 Duo is a higher performance CPU than the Pentium Dual Core, because it uses a newer microarchitecture, the "Intel Core Architecture, version 2" - "Core 2". Core 2 Duo means that the CPU has two Core-2 cores. In my opinion, the marketing teams intentionally made the names confusing to obfuscate easy decision-making on the part of the consumer (but I'm a bit of a cynic). Pay close attention to whether "Core" is capitalized or not; and Dual-Core vs. dual core - this should help differentiate between descriptive vs. "brand-name" usage.
Take a look at Pentium Dual-Core and Core 2 Duo for technical overviews of the Intel CPU series/brands. Also see dual core (for the generic term) and how it is understood by computer architects. The technical details of the different Intel CPU series are a bit dense for a beginner; your best bet is to read these articles and also take a look at the different processors in each series]. But briefly, all Core 2 CPUs are 64 bit CPUs built with newer technology; the Pentium Dual-Core is sort of a souped up Pentium D (which is a souped up Pentium 4). The lowest-end processors in both series actually do not have two cores. Nimur (talk) 05:30, 30 July 2009 (UTC)
The second last statement isn't accurate. Pentium Dual-Cores have all been Core based, either 32 bit Core or 64 bit Core 2. They've had cut down cache and reduced FSB. Nil Einne (talk)
Are you sure? Can you find a specific Pentium Dual-Core processor that used the Core 2 architecture? Nimur (talk) 02:00, 3 August 2009 (UTC)
I'd just like to point out a small technical inaccuracy in the above explanation: "can simultaneously process two instructions" is not technically correct. At least in the Intel case, each of these two cores is superscalar, and hence it would be more technically correct to write "can simultaneously process two different instruction sequences", or similar, as each of the cores may at each time process more than one instruction that follow on each other. (talk) 16:43, 5 August 2009 (UTC)

Lenovo Laptop[edit]

I will be purchasing a laptop within the next two weeks and wondered if anyone had any experience with Lenovo. I had not heard of this company prior to reading an ad in the paper, and I did know if they were a good manufacturer of laptops. If anyone has any strong preferences for laptops, please let me know that as well. Thanks. --Think Fast (talk) 05:55, 30 July 2009 (UTC)

Lenovo is the Chinese company which bought the PC division from IBM. They now own the rights to manufacture ThinkPads, and in my opinion, they continue to produce fine quality, sturdy computers. Every mobile computer I have ever purchased (in fact, every mobile computer I have ever used for business, too) has been either an IBM or Lenovo system; I currently use an Lenovo IdeaPad S10e mobile computer for portable computing. In the next few days, a story about my unconventional uses for my ThinkPads may be appearing on the Lenovo website; I'll keep you posted if they decide to publish it... Nimur (talk) 06:07, 30 July 2009 (UTC)
What is that? can you tell us, the cylinder bottom right looks vaguely like a thermolysis chamber but the metal plates on the end are about 2" thick. Is it safe/legal? (talk) 09:15, 30 July 2009 (UTC)
Rocket Powered -Nimur (talk) 16:21, 3 August 2009 (UTC)
Looks like I'm late for this one, but I'll stick my two cents here. The only two laptop companies I never heard anything bad about are Lenovo and ASUS. I've been selling computers for about two years. Mxvxnyxvxn (talk) 22:09, 5 August 2009 (UTC)

Vista and USB flash drive[edit]

I'm new to Windows Vista and I just plugged my USB flash drive into my laptop whereupon Windows asked whether I wanted to scan the disk for errors that may have been caused by not waiting for file writes to complete. I elected to perform the scan but after a long period of scanning (about 30 minutes or so), no progress had been made at all, according to the progress meter. I note that when starting certain systems up with the flash drive already plugged in, Windows also asks to scan it and then seemingly makes no progress. Is it sensible to scan flash drives for errors in this way and if so, should it take such a long time? ----Seans Potato Business 06:48, 30 July 2009 (UTC)

As I understand it (most) flash controllers automatically isolate any bad(broken) sectors and remove them from the usuable memory - so there should be no need to scan for errors, also since it does work I would suggest not to use it.
However I seem to remember reading that vista has specific support for flash drives - so it should know what it's doing - which in a bit contradictory - I'll see if I can find out more, or maybe someone else will have the answer. (talk) 09:43, 30 July 2009 (UTC)
Bad sectors aren't the real issue here. The issue is potential file system errors because writing to the flash disk may not be complete. This is more likely to be a problem if the file system is FAT, which it probably is Nil Einne (talk) 19:40, 2 August 2009 (UTC)
I usually go ahead and run the scan, but if it looks like it's going to take a long time I just cancel it. If you eject/unmount the drive properly before pulling it out, this sort of thing shouldn't come up in the future. If the last files you copied over or edited on the flash drive weren't that important, you can probably skip the disk scan. But keep in mind, if it comes up a lot, it could be an indication that the drive is reaching the end of its useful life. Probably nothing though. Indeterminate (talk) 10:57, 30 July 2009 (UTC)
I skip these scans and have noticed no ill effects. Of course, your mileage may vary. Tempshill (talk) 19:31, 30 July 2009 (UTC)

Advantages and Disadvantages of Window Vista Ultimate[edit]

Can anyone tell me what is the advantages and disadvantages of window vista ultimate ? wait for your reply ya~ tq —Preceding unsigned comment added by Bebezaii (talkcontribs) 11:50, 30 July 2009 (UTC)

Advantages and disadvantages of WVU as compared with what, exactly? -- Hoary (talk) 12:11, 30 July 2009 (UTC)
In comparison to other vista editions see (talk) 13:09, 30 July 2009 (UTC)
The only disadvantage compared to other Vista editions is that it is more expensive, and maybe you won't really use the extra stuff you are paying for. (See the comparison link above.) -- (talk) 14:02, 30 July 2009 (UTC)
It probably takes up more disk space too. (a few percent perhaps?) - I haven't got any exact figures on that... (talk) 14:33, 30 July 2009 (UTC)
I think the correct answer is not very much when compared to Windows Vista Professional Edition. Rjwilmsi 20:38, 31 July 2009 (UTC)

A freeware suite for Windows XP[edit]

I've already got OpenOffice installed. What other free software is worth installing for the general user please? (talk) 12:01, 30 July 2009 (UTC)

I find OpenOffice Calc agonizingly slow for the kind of work I most often want to do with it and have taken to using Gnumeric instead. In my case it's not for Windows XP or indeed Windows anything, but I suppose that the "platform" doesn't matter. Other free software for Windows? IrfanView, and of course some alternative to Internet Explorer (I have found K-meleon a lot faster than Firefox). And the Gimp. -- Hoary (talk) 12:09, 30 July 2009 (UTC)
What does the general user want to be able to do? And do you mean free gratis or free libre? Algebraist 12:19, 30 July 2009 (UTC)
This list might be of interest to you: 40 free Windows apps. — QuantumEleven 12:23, 30 July 2009 (UTC)
VLC media player to play audio and video; Mozilla Firefox to browse the web (and/or Google Chrome); Mozilla Thunderbird for email; GIMP for editing pictures; Inkscape to edit diagrams, maps, posters etc.; Adobe Reader or Foxit Reader to read PDF files and FreePDF-xp to create them; AVG free for anti virus; Audacity to edit sound files and Avidemux to edit video; TUGZip to read and write zip files and the like; InfraRecorder to burn CDs and DVDs; Spotify to listen to music online; uTorrent for bittorrenting; Filezilla for FTP; Spybot search and destroy to fight spyware; Scribus for desktop publishing; emule for file sharing; and Google Earth and NASA Worldwind for maps and stuff. -- Finlay McWalter Talk 12:50, 30 July 2009 (UTC)
HandBrake+DVD Decrypter to backup your legally owned DVDs; Password safe to store your passwords. -- Finlay McWalterTalk 12:58, 30 July 2009 (UTC)
Celestia is a fun science toy. It's a really slick 3D astronomy simulator that lets you fly around the universe (accurately representing distances, if not travel-times). Nimur (talk) 15:05, 30 July 2009 (UTC)

For audio and video I would suggest Media Player Classic with ffdshow // 21:55, 30 July 2009 (UTC)

Mp3tag for tagging MP3 files; TeamViewer for remote desktop; Recuva for file recovery; MyPhoneExplorer for my Sony phone (the Sony app sux); CDBurnerXP for CD/DVD authoring; GSpot to identify video codecs. ---— Gadget850 (Ed) talk 22:28, 30 July 2009 (UTC)
If you use facebook or twitter a lot, flock is a browser you might want to try. If you want to rip your CD collection and move your music to your PC, you will find Exact Audio Copy useful, possibly in combination with the FLAC software. If you want to tag mp3 files, and hate iTunes and similar programs that want to take charge of your entire media collection, foobar2000 might be the media player for you. I wasn't aware of Mp3tag, thanks Gadget850, I will want to try that one out. If you want to compress and decompress files and folders, 7-zip is useful. I wasn't aware of TUGZip either, thanks Finlay McWalter, I'll try that one out too! --NorwegianBlue talk 17:38, 31 July 2009 (UTC)

Solaris Operating System[edit]

Can anyone tell me what is Solaris Operating System?? What is the functionality of it? —Preceding unsigned comment added by Bebezaii (talkcontribs) 14:16, 30 July 2009 (UTC)

Solaris (operating system). --LarryMac | Talk 14:21, 30 July 2009 (UTC)
See also Comparison of operating systems and (if you're a technical type) Comparison of operating system kernels. -- (talk) 20:25, 30 July 2009 (UTC)
Solaris is the largest (by market-share) true Unix platform that is commercially marketed. Unix is the operating system which inspired Linux; Solaris is one version that is designed and marketed by Sun Microsystems. Solaris had particularly strong support for Sun's hardware (espcially the SPARC processor series); it was primarily designed to support extremely high-end server and mainfraim systems, though its most recent incarnations are suitable for use on desktop and personal workstations as well.
Because of recent business changes (Sun was acquired by Oracle Corporation), as well as the increasing popularity of free Linux (and Unix systems like OpenBSD), it is not clear what the future holds for Solaris. Most of the system was released as OpenSolaris, a free, free version, in 2007; it is very likely that for this reason some incarnations of Solaris will continue to live on in enterprise environments. Nimur (talk) 01:22, 31 July 2009 (UTC)

Cost of video streaming[edit]

Recently, I read that one hour of video streaming costs 0,25c. Is that correct? Since I am constantly in YouTube, I have caused them cost of some thousand dollars...--Quest09 (talk) 18:34, 30 July 2009 (UTC)

Uh, what? The cost of the bandwidth, of course, might be counted but that's almost infinitesimal for a site as large as Youtube. I've never heard of a site charging $0.25 per hour for streaming video, although it sounds like a plausible business model. But despite what they charge, no, it doesn't cost a webmaster 25 cents to stream an hour of video. ZS 18:47, 30 July 2009 (UTC)
Since YouTube has advertising on their pages (and in their videos), you're not costing them the full cost of streaming video to you. Ideally, they should be making more money from showing you the advertisements than it costs to stream the video. I recall hearing that the YouTube division of Google is not yet profitable (that is, their total costs are more than their total revenues), but I'm sure they're looking into ways of narrowing that gap. -- (talk) 20:23, 30 July 2009 (UTC)
It really depends on how you want to measure costs. In some sense, the enterprise scale system costs a fixed amount to operate, whether it is serving a video or sitting idly and warming a server room. However, this is not actually an accurate representation of the way that enterprise business data centers work in 2009 - a modern content delivery network can be outsourced, and can bill based on actual usage statistics. The price point that a CDN will charge an organization is going to vary widely depending on what is actually contractually delivered. (You can think of this as renting a percentage of a data center for each second that it is being used; and closely monitoring to make sure that every moment, you only rent as many servers as you actually use). I believe that Google does not choose to outsource, but instead runs its own CDN and data centers internally; that means it is harder to put a precise number on their costs. Even if such a number exists, it is highly proprietary market data, so it is unlikely that the estimates you hear quoted are accurate. Nimur (talk) 01:29, 31 July 2009 (UTC)
What if it really was .25 cents (as in, a quarter of a penny) as the OP originally stated... -- (talk) 17:10, 31 July 2009 (UTC)

I just came up an advertisement for http:// streamapi dot com / One hour of 256 kbit costs 5c and one hour of "Full HD" costs 20c. Of course, that's just some random advertisement I saw. It is a white-label solution so it probably as expensive as it gets. Kushal (talk) 20:00, 31 July 2009 (UTC)

Note that these estimates vary by a factor of about 100x (20 cents to 0.25 cents) - that gives you an idea of the uncertainty in price estimation! In either case, the original poster brings up the valid point - your "free online viewing" experience is being heavily subsidized by somebody else. Is Google losing money on the video transactions? Or are they recuperating their losses by charging advertisers? If so, are advertisers really returning on their investment at such a steep price? These are all valid questions; but if you consider the cost of operating a television broadcast antenna, cable television network, etc., you might get some perspective. For the last fifty or hundred years, people have been paying top dollar to influence mass media. This sends up a red flag of paranoia in me - why is it so important that I see these people's productions, that they will spend so much money on them? Nimur (talk) 00:01, 1 August 2009 (UTC)

Yes, I said 0.25 cents, that makes 4 hours for 1 cent. Apparently, this estimation is not far from the truth. --Quest09 (talk) 19:03, 1 August 2009 (UTC)