Wikipedia:Reference desk/Archives/Computing/2014 January 24

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January 24

Why are these seemingly identical scanners priced so differently?

I'm looking for a new scanner for the office and I've found what I consider to be a decently-priced scanner on eBay, listed from two sellers: [1] [2]. Why is one $50 but the other is $120?

Also, will these scanners work right outside of the box, i.e. some assembley may be required, but assuming they deliver what they promise, I can plug it into the computer and start scanning documents? It's the "no software included" caveat in particular I'm tentative about. --Ye Olde Luke (talk) 00:49, 24 January 2014 (UTC)

The most obvious explanation for wildly different prices on an auction site for what appear to be two near-identical examples of the same thing is different strategies for reaching a high closing price, perhaps combined with different levels of optimism about that closing price.

Is additional software needed, and if so, is it unavailable by legally free-of-charge downloading? Well, google the matter and see. (You'll need to specify your operating system.) Morenoodles (talk) 01:17, 24 January 2014 (UTC)

Pricing on eBay often has no rationale. But the $50 one is from a batch of six. --  Gadget850 ^talk 01:25, 24 January 2014 (UTC)

"AMD Unsupported Hardware" warning

On a computer with an AMD A4-6300 APU, Radeon R7 240 video card and Linux Mint 16, after installing fglrx, I get a watermark in the bottom right corner of the screen saying "AMD Unsupported Hardware". The APU and video card aren't a supported Dual Graphics pair, but I didn't consider this a problem when buying them because the computer is intended to use both GPUs to run OpenCL tasks experimentally (probably via INRIA's StarPU and modified versions of it) for a master's thesis, rather than for graphics. Would the lack of Dual Graphics compatibility explain the Unsupported Hardware warning assuming nothing else is wrong? Will it affect my ability to use both GPUs separately for OpenCL? NeonMerlin 00:55, 24 January 2014 (UTC)

In case it makes a difference, fglrxinfo's output includes "OpenGL renderer string: AMD Radeon HD 8500 series", even though I believe both the integrated and discrete GPUs are newer than that. NeonMerlin 01:08, 24 January 2014 (UTC)

And in case this makes a difference, the output to the monitor is running through the video card, since the system failed to output video from the APU through the onboard VGA port during installation. (Only one monitor, an LCD at 1280x1024x60Hz with 24-bit color, is connected.) NeonMerlin 01:23, 24 January 2014 (UTC)

Have you tried downloading directly from AMD? [[3]] From what I've seen with some searching is that their latest release is newer than what is shipping with the fglrx package, but I haven't really dug into it much, so I could have missed something. I haven't done Linux+AMD graphics in 8 years or so, so I probably won't be any more help on this one. Katie R (talk) 13:11, 24 January 2014 (UTC)

Question regarding email

If emails are received in frequent intervals in spam folder each from a different mailid and I receive it as forwarded copy and it contains explicit content .The emails are without any attachment and contain a url part of which is dl.dropboxusercontent.com and the rest is number is a user id .The emailids as I can make out are from domains as diverse as Russia,Mexico,France,Japan,USA and many others.By the way I have not clicked on the url.I want to find out the source(s) of these mysterious emails.Can they affect my computer system in a harmful way even when I have not clicked on the link dl.dropboxusercontent.com.I want to know who are sending these emails? What is their intention.Do they want to the infect unsuspecting users computers through viruses.Please someone shed light onthis topic.Thanks.117.194.236.155 (talk) 05:05, 24 January 2014 (UTC)

Firstly, DO NOT CLICK THE LINK. It should go without saying, but it's worth stating the obvious sometimes. Secondly, the source may well be a botnet which is being used to send the emails out, making the actual origin almost impossible to trace. Most likely, it's a virus, and they are relying on people being stupid enough to click the link (send an email to enough people, and one or two of them will be tired, not thinkin straight, and expecting a file from someone else, or just have more curiosity than internet safety knowledge). As for affecting you if you do not click the link, unless there's a vulnerability in the program you use to access your mail, this isn't possible. MChesterMC (talk) 09:30, 24 January 2014 (UTC)

Windows Vista SystemSoundsService, TMM, UserTask, and SystemTask: does anyone without a security clearance know why they rewrite the entire hard drive?

It's been quite a while since Windows Vista first came out. But I've never seen anything that much improves on the comments of irate bloggers like [4]. These four tasks are scheduled to run quite frequently by Vista, and interfere with performance if something like Windows Defender happens to run at the same time. Looking at the Task Scheduler, Task Manager/performance data, it appears that on an old system they read a nominally 40 GB hard drive at 20 MB/sec, and take roughly half an hour to read (via a service) and write (via System), which works out to essentially the entire hard drive. Now this sounds suspicious, and the bloggers on the net seem to favor two conspiratorial explanations, to which I'll add a third:

• I. It's malware infection

• I. (a) It's digital rights management

• II. It's the NSA.

Looking up these things on Microsoft I get the manual [5] which does not really explain how it is that TMM would need to go through the entire hard drive. For SystemTask and UserTask they have only the vague blurb (identical for both):

This scheduled task runs when you start the computer and after you modify the scheduled task. This scheduled task helps manage digital identities such as certificates, keys, and credentials for users and for the computer. This scheduled task also enables enrollment, roaming, and other services.

Can anyone provide information to explain what these are doing with the disk, or at least to evaluate the suspicious explanations? Thanks. Wnt (talk) 13:47, 24 January 2014 (UTC)

The "bloggers on the net" are just a bunch of random people who like to say exciting things to attract readers, and the one you linked is obviously not very technically savvy—for example, he seems to think that running defrag at low priority would prevent it slowing down his system, which is unlikely since defrag is normally disk-bound and the process priority only affects CPU scheduling. He apparently doesn't know how to determine the priority of a running process, since he says he just assumes they're running at normal priority because they're bogging down his system. And then at the bottom of the post you find out that disabling all of those scheduled tasks didn't actually fix the performance problem that he'd originally blamed on them. So I'm not sure what the point of the whole thing is supposed to be. Also, he didn't say anything about any tasks reading/writing the disk at 20 MB/s, which seems to be your main concern.

Getting back to that, I'm pretty sure it's not normal for these processes to read 20MB/s from the disk for extended periods of time, and I'm even more sure it's not normal for them to write that much. My best guess is that they aren't, and you misinterpreted whatever led you to think otherwise. For example, you said the reading and writing were happening in different processes, at the same rate. If they were also happening at the same time, then it was likely IPC between those processes and not disk access at all. Also, if those 20-megabyte numbers were from the "I/O Read Bytes" and "I/O Write Bytes" columns of Task Manager, those columns are totals over the lifetime of the process, not per second. If that doesn't answer your question, please provide more details about where you got the 20MB/s from. -- BenRG (talk) 00:57, 25 January 2014 (UTC)

Ooops, it was B/min, sorry! And no, These numbers come from the "Reliability and performance manager" / "Resource Monitor" (the first being what you say to open, the second being what the window is titled). The disk in this instance was indeed reported at 100% capacity for nearly half an hour, though, and it was the one category that was consistently maxed out while the computer was showing very sluggish performance. Wnt (talk) 01:16, 25 January 2014 (UTC)