Wikipedia:Reference desk/Archives/Computing/2009 March 20

= March 20 =

SLI in 8x?
Hi,

I remember reading on a motherboard specification (don't fully recall the model, but it was a cheaper Foxconn one) had 2 16x PCIE slots, but mentioned that using SLI would run both slots as 8x... Doesnt that defeat the purpose of using SLI? Or does the bus speed not matter as much as the combined computing power?

TIA PrinzPH (talk) 01:05, 20 March 2009 (UTC)


 * Well, there are many things going on when measuring graphics performance - bandwidth into the card is only one of them So, sure, you lose out on the amount of data you can send to the card per second...but if you are trying to (say) drive three high-resolution monitors from the system, the limiting factor is more likely to be the rate that the system can push pixels - not the rate that vertex data can be fed to the GPU.  So in that case, doubling your pixel throughput rate by using SLI is more than worth the cost of reduced geometric complexity.  It's a tricky business - a lot depends on how you are using the card - and what software you are using.  SteveBaker (talk) 04:35, 20 March 2009 (UTC)


 * Thanks for the response. I was looking at it strictly from a gaming standpoint. How does it affect a title like Crysis for example. 119.92.84.120 (talk) 11:24, 20 March 2009 (UTC) Forgot to login :s PrinzPH (talk) 11:26, 20 March 2009 (UTC)


 * I assumed you were talking about games. But as I said "it depends" - mostly it depends on whether you're running multiple monitors at high resolution or not.  But still - no two  games are alike.  It's tough to know in general. SteveBaker (talk) 02:05, 21 March 2009 (UTC)


 * It also depends on whether you're referring to PCIe 2.0 or 1.1 slots (and cards). If the slot is PCIe 2.0 then 8x will already have the same bandwidth as 16x with PCIe 1.1. However from what I've seen in general, 8x is generally enough for most cards including with SLI with a minimal performance hit. Probably PCIe 1.1 at 8x is no longer enough for the top gen cards and it's been a while since I've really looked in to it; not that it's something I've looked in too much ever (since SLI has always seemed a dumb thing to me, only worth it if you're talking about the absolute top cards or perhaps situations like SB discusses with multiple monitors). Edit: This although slightly old may be of interest Nil Einne (talk) 12:18, 23 March 2009 (UTC)

Turning off a computer on a network via dos
Are there a set of DOS commands that can turn off a computer other that the one being used on a network? SHUTDOWN attempts to give help but I can't make much scene from it. -- penubag  (talk) 05:45, 20 March 2009 (UTC)
 * Just to confirm, is this DOS within Windows? Also what operating system is running on the computer you are trying to shutdown? If both are running Windows then yes the "shutdown" command will work: shutdown /m \\COMPUTER /s /t 30 /c "Shutting down" /f /d 0:0 would shut down COMPUTER (change the name) with a 30 second warning and force applications to close (/f). The /c is the comment to display on the machine and /d is the reason code just for logging purposes (0:0 is unplanned other). You will however need to have access on the other machine so if it says access denied you could send a net use \\COMPUTER /user:domain\username first to authenticate it. Hope this is of some help! ZX81  talk  11:01, 20 March 2009 (UTC)


 * Yeah, from what I can tell, you can use the "shutdown" command to turn off a computer on the network. For example, if the computer's name was PENUBAG, you could type "shutdown -s -f -m \\PENUBAG" to turn it off. ("-s" is the command to shut down, "-f" forces all programs to terminate -- otherwise, all it takes is an open document in Notepad to hang the process -- and "-m \\PENUBAG" is the command to the remote computer.) I'm not sure about what kinds of access rights this would require to work, though. You probably need to be a network administrator, and of course you'd need to be in the same LAN with the target computer. -- Captain Disdain (talk) 11:04, 20 March 2009 (UTC)


 * ...huh, didn't get an edit conflict. Had I know that ZX81 was on the case as well as he was, I wouldn't have posted my response at all! -- Captain Disdain (talk) 11:05, 20 March 2009 (UTC)


 * I'm running MS Vista and the target is an MS XP, which are connected by a LAN. Both ZX81's and Captain Disdain's method returns "Access Denied. (5)". ZX81, could you elaborate more on the "net use" command? Would I do this on the Vista? The target computer's name is DININGROOM so is this correct? net use \\DININGROOM /user:domain\Kevin (Kevin is my username on the target). Thank you for your help so far. -- penubag  (talk) 22:50, 20 March 2009 (UTC)


 * I have actually tried this command and fell foul of the access rights. In the end I downloaded a remote boot/shutdown utility.  I would provide a link, but can't remember what it was called.  I found it by googling for "remote boot" or "network boot" (the shutdown bit usually came as a bonus with these remote utilities).  Astronaut (talk) 12:47, 20 March 2009 (UTC)


 * You may want to check out PsShutdown, a tool which is part of PsTools. I also use PsExec frequently. ←  Spidern  →  15:48, 20 March 2009 (UTC)
 * I downloaded this on my Vista but it doesn't seem to work. The help file (Pstools.chm) says "Navigation to the page was canceled" and any of the .exe files briefly show the command line before closing without any noticeable effect. -- penubag  (talk) 22:50, 20 March 2009 (UTC)
 * The PsTools utilities are all for use on the command line and they all expect parameters (so they can be used in scripts etc if needed) which is why you see them popup and vanish so quickly. If you open up a command prompt and run them from that you'll be able to read the text and see the parameters you need to specify. Regarding the .chm help file, it's likely you need to unblock it - see here for more information on that. ZX81  talk  04:17, 21 March 2009 (UTC)
 * Sorry, I'm not that well versed in all this but when I typed psshutdown.exe in the command line it says psshutdown.exe isn't a recognized command. Could elaborate on that bit? Thanks, ZX81 -- penubag  (talk) 06:08, 21 March 2009 (UTC)
 * Well, in order to run a program, you have to be in the folder where that program is located. You can also copy the program to a folder in your path, like C:\WINDOWS, and then you'll be able to evoke it anywhere. You use the cd command to change directories (folders). But it's not as if any of this will actually work, because you need to disable most of the safeguards against attack on the other machine first. For example, if the firewall is on the victim's machine, turn it off (or at least open a hole for NetBIOS). Likewise, if you want to evoke the net use command, you need to share the root drive of the victim's machine, from the victim's machine. You also need to type secpol.msc in the search or run box on the victim's machine, then go to Local Policies, then User rights assignment and allow "everyone" (literally, that's the user name) to access the computer, shut down the system, etc. In other words, you need to make the computer a sitting duck on the network. This is what some viruses do, so just make sure you don't have anything important on that computer before you do this (like tax returns) because it's about 20 minutes before a vulnerable networked machine is "owned" by a worm nowadays. If I understand you correctly, you also have a router (or switch). Some routers will help protect you against external threats (using their default configuration), so just be careful not to connect directly to the Internet.--K;;m5m k;;m5m (talk) 11:51, 21 March 2009 (UTC)
 * I hate to directly disagree with another Wikipedian, but because of the security implications of this I feel I should say something. There's really no need to allow "everyone" access and it would be far more secure to create an admin user on that remote machine (if one doesn't already exist) so you have a specific username/password, but if it is a home network the user may not mind this lack of security. Likewise you don't need to create an open share on the root of the drive, if file sharing is turned on then Windows itself will already share the root of the drives as hidden admin shares like \\computer\C$ and only users with admin access on the machine will be able to access it. Finally, the net use command doesn't need to be used to map a drive which I think was what you meant with regarding to sharing the drive, you can use it simply use it as in my example above to authenticate to the remote computer (so that you can perform other activities like shutting it down). ZX81  talk  13:45, 21 March 2009 (UTC)

Really? You don't need to share the drive? You just wrote "C$", which is the root of the drive. I turn off sharing and this is what happens: C:\> net use \\192.168.1.101\ipc$ System error 67 has occured.

The network name cannot be found.

C:\> net use \\192.168.1.101\C$ System error 67 has occured.

The network name cannot be found. So, now I right-click on the drive and select Properties, then Sharing and create a share: C:\> net use \\192.168.1.101\ipc$ The command completed successfully.

C:\> net use \\192.168.1.101\C$ The command completed successfully. And no, it's going to be difficult to get complete access to that computer if the username on the local machine is different from that on the remote machine. Hence, you allow everyone access. And this is with "Simple file sharing" disabled, given you need to edit the ACLs to specify what they can access, anyway.--K;;m5m k;;m5m (talk) 14:58, 21 March 2009 (UTC)
 * Sorry, but I'm not really sure what point you're trying to make. As I said above if folder sharing is turned on then Windows itself creates the hidden shares (and from your examples you've demonstrated this). "net use" isn't used ONLY to access a specific share and you can leave the share name off if you just want to authenticate with the computer itself net use \\COMPUTER /user:domain\username and that's what this question was about (turning off a remote computer - once you've authenticated to it). You've started talking about access lists on the filesystem and folder shares and I don't see how that's related or required. ZX81  talk  15:18, 21 March 2009 (UTC)
 * Whichever method he chooses, it's not as simple as executing a net use command. He'll have to allow other users to shut down his computer via the secpol.msc snap-in or via the registry. Settings for the firewall, services.msc, sharing, and ncpa.cpl (to enable netBIOS) also usually have to be tweaked. I'm not sure if we'll be able to walk him through the steps to allow a specific account, but you can try.--K;;m5m k;;m5m (talk) 15:46, 21 March 2009 (UTC)
 * The original poster has already confirmed that the error message they get is "Access denied" so we know there's no firewall/connectivity issue and likewise we know NetBIOS is turned on to be getting that error (the Windows default) so the problem is purely an authentication one and with all due respect you seem to be making it over complicated. By default Windows allows local administrators to shut the computer down so there's really no need to change any of the policies IF the user has administrator access on that remote machine and although it's an assumption, if this is a home network they more than likely do. Penubag, you wrote above about "Kevin" being your username on the XP machine to be shutdown, I assume that Kevin has admin rights (and isn't a limited user) do they also will have a password? (built in XP security stops authenticating over the network with a blank password so you will need to give them one). If so you can use the following: net use \\DININGROOM /user:DININGROOM\Kevin If needed it will prompt for the password or optionally you can add the password on the end of the net use command and it will return The command completed successfully. if it worked. After this you should be able to re-run the shutdown command without a problem. ZX81  talk  16:46, 21 March 2009 (UTC)
 * Thanks guys for all your help so far. Yes, I am and administrator on both computers and not a limited user. I tried what you said net use \\DININGROOM /user:DININGROOM\Kevin but the command line returns: "System error 1219 has occurred. Multiple connections to a server or shared resource by the same user, using more than one user name, are not allowed. Disconnect all previous connections to the server or shared resource and try again." Perhaps this is because my user name on the Vista is Kevin Duke and not Kevin? I don't know. I appreciate your support.-- penubag  (talk) 23:56, 21 March 2009 (UTC)
 * Yes it's because the Vista machine has already tried to access the XP computer since you last rebooted (probably via filesharing?) so it's already picked up the "Kevin Duke" name. If it's an option the easiest way to fix this would be just create an additional user on the XP machine called "Kevin Duke" with the same password as you use on the Vista machine. It doesn't have to actually be logged in/used, it merely has to exist. ZX81  talk  00:52, 22 March 2009 (UTC)
 * I renamed my XP name from Kevin to Kevin Duke so now I have the same names and passwords on both computers, but the same problem persists. I've already tried restarting both computers. net use \\DININGROOM /user:DININGROOM\Kevin_Duke returns the same "System error  1219..." but this time it took much longer if that means anything. Do I need to enter a password? I also tried combining both the commands on one line in this image and File:Net use cmd.png tried showing some net use syntax which shows a password. I really appreciate your support so far. -- penubag  (talk) 04:03, 22 March 2009 (UTC)
 * No I'm afraid you can't combine the net use/shutdown command together, but can you confirm the username is Kevin Duke or Kevin_Duke? (you originally wrote with a space, but now you're using an underscore - Assuming it's a space it'll need to be in quotes and possibly the computer name in the username is throwing it out so. Two more things to try:
 * net use \\DININGROOM /user:"Kevin Duke"
 * net use \\192.168.1.1 /user:"Kevin Duke"
 * You'll need to replace 192.168.1.1 with whatever the IP address is of your XP machine and it should prompt you for a password if needed (or you can put it on the end of the command). Likewise if the IP address works you can just use \\192.168.1.1 in the shutdown command. Hope this helps more. ZX81  talk  18:24, 23 March 2009 (UTC)

I think I know what may be the problem. My account on the XP is Kevin and on the Vista is Kevin Duke. I renamed my XP to Kevin Duke but renaming and account doesn't change the directory or other system files(?). I've had much problem with this in the past and remembered about it now. So even if I rename my account, the directories don't change (see below). But if the directories not changing doesn't have to do with anything this is what I get on the command line File:Netuse shutdown denied.png. -- penubag  (talk) 23:25, 23 March 2009 (UTC) I just tried this on my XP trying to connect to the Vista and it works. But when it prompts for a password I can't input any text. Why's that? The only key that works is the Enter key and all that returns is "bad password". It might just be that I need to input the password in the same line as the command, but I wonder why this works on the XP and not the vista. Could it be security settings on the XP? -- penubag  (talk) 01:29, 24 March 2009 (UTC)

Li-ion battery
Is it healthy to leave a li-ion battery (as for a laptop) plugged in at all times when not in use and only unplugged when away from a power source as long as it's kept cool? Our Wikipedia article says to recharge often and to avoid complete discharge, which is the complete opposite ideology I've had with Nickel-cadmium.-- penubag  (talk) 05:53, 20 March 2009 (UTC)


 * This depends heavily on the design of the laptop. Each of the following designs are valid and exist:
 * Laptop always uses the battery. Plugging it in only causes the battery to charge up slightly faster than you discharge it by using it.  So, leaving it plugged in all the time is just charging it while you discharge it.
 * Laptop will disconnect the battery completely while you have it turned on and plugged in. It only charges the battery if you turn off the computer and plug it in.  So, leaving it plugged in and on all the time has nothing to do with the battery.
 * When plugged in and turned on, power comes from the wall outlet to run the computer. Some power is split away to charge the battery as needed.  When the battery is fully charged, it just stops charging it.
 * Since I have no way to know what kind of laptop you have, I have no way to know how it is designed. What I can say is that any respectable charger will not overcharge your battery.  So, once it is charged, leaving it plugged in does nothing except waste a few watts of electricity. --  k a i n a w &trade; 15:25, 20 March 2009 (UTC)
 * I'm using a Dell Studio laptop and when I plug it in the battery status says "idle" instead of "discharging". So how would you interpret this? Would it be reasonable to leave this plugged in and charging for weeks on end without discharging a little? -- penubag  (talk) 22:56, 20 March 2009 (UTC)
 * As kainaw mentioned above we have no way to know how it was designed, but personally I would suspect that due it is constantly being "topped" up to make sure it remains fully charged. Although it's more a workaround than answering your question, you could always just remove the battery and run the laptop without it? Most laptops that are plugged in will run quite happily without one and if anything it'll be a little cooler without the heat from the battery charging. If you do decide to do this for long periods of time I would recommend making sure the battery level is around 50% to help extend the life of the battery - There's more information about this in our Lithium-ion article. ZX81  talk  04:31, 21 March 2009 (UTC)
 * If working without a battery, beware that a power outage (or carelessly pulling the plug) may lose your work in progress. Certes (talk) 13:32, 21 March 2009 (UTC)

"Looking glass" for SMS routing
Hi,

I'd like to know if there's a service similar to the Looking Glass services provided on the IPv4/IPv6 Internet, but for SMS routing instead. If not, how can I discover how a SMS is routed from its source to its destination? I'm aware that there are SMTP-to-SMS gateways, but I'd like to know how a new CLEC telephone provider would implement SMS into, say, an existing VoIP system. (The internal part of the CLEC's implementation is assumed to be a simple SMS-to-SMTP mailbox.)

Props to those who can shed some insight. Thanks for all who read this.

jdstroy (talk) 15:41, 20 March 2009 (UTC)


 * To clarify, here are examples of two Looking Glass servers: Level 3 LG, Qwest LG jdstroy (talk) 19:01, 20 March 2009 (UTC)


 * Assuming lookingglass is little more than a BGP aware traceroute-like utility, I doubt it. Once SMS goes from the phone or user to the cell phone network, it's proprietary. Unlike TCP there's no sendback (as far as I understand) making SMS a lot more like UDP. Then again, I know very little about SMS so maybe someone out there's done this. Shadowjams (talk) 04:29, 25 March 2009 (UTC)

Unbearable low screen resolution on Vista which is impossible to alter by normal methods. Help!
I was playing a full-screen game on my Vista laptop (you know, one of those games trhat changes your screen resolution), and got stuck in an infinite loop, which there was no way to get out of, due to a bug.

I pressed, but the screen resolution was too low to reach the task manager (because of that stupid screen Vista brings up with options no-one uses), so I logged off (it was either that or cancel).

Unfortunately, it retained the screen resolution settings of the game, which is the lowest I have ever seen. It has rendered my laptop almost completely unusable.

In fact - it's so bad, I can't get to the screen resolution settings in the control panel.

It works perfectly in safe mode, if that's any help, and startup repair doesn't change anything.

Is there any way out of this without losing all my files?

Please help! Den dodge  Talk Contribs 21:01, 20 March 2009 (UTC)


 * You can change your resolution even though you cannot see all windows on the screen. First, start the control panel by using Win+R, typing "control desktop" and pressing Enter. Now, press Tab six times, to select the "Screen settings" (or whatever it is called in English) option. Press Enter. Now you need to set focus to the resolution slider, by using Alt+AccCh, where AccCh is the underlined character in the slider's text label. Because I have a Swedish Vista, I do not know what character this is. However, you can press Tab a few times (probably two times is the right number), and hope you have focused the right control. Now, select the highest supported resolution by pressing End. Finally, press Enter. To be sure, it might be an idea to press Tab a third time after having pressed End, and then press End again, and Tab a fourth time, and End yet again, to make sure that the resolution slider really has been set to the right-most value. --Andreas Rejbrand (talk) 21:27, 20 March 2009 (UTC)


 * In English, the key combo to access the screen resolution slider is Alt+R. After that, simply press End then Enter to set the screen resolution to max supported.  Once you can see waht you are doing, you will probably have to go back and reset your video settings properly.
 * If that situation is repeated in future, bring up the Task Manager. Then press Alt-Space followed by "M", you should now be able to move the task manager around with the arrow keys to bring it into sight so you can resize, kill your game, and so on.  Astronaut (talk) 23:01, 20 March 2009 (UTC)


 * The other option is to just restart or alternatively if this isn't possible turn off (if your power button is set up turn off the computer this is a good way if you can't use the shutdown options in Windows) and then start back up your computer and then press F8 to get the boot options and select VGA mode rather then safe mode. You should go to 640x480 from which you can then change your resolution etc and it will stay when you restart (actually you may have to restart your computer after going to VGA mode before you can change the settings properly) Nil Einne (talk) 12:39, 23 March 2009 (UTC)

Old-header (Windows 1.0 and 2.0) bitmaps
Where can I find old Windows Bitmaps, using the old headers from Windows 1.0 and 2.0? I am writing a high-compatibility image viewer, and would like to test some old files. --Andreas Rejbrand (talk) 21:29, 20 March 2009 (UTC)