C# analog clock runs slow on some computers

C# analog clock runs slow on some computers

• SamuelNguyen

  Greets,
  
     When you say it "runs slow", I imagine that it isn't that it doesn't show the correct time, just that it seems to update a bit slower than other machines.  If that's the case, and you really want to investigate things at a lower level:
  
  a) examine the hardware that is installed on the comparable machines;
  b) examine the drivers used for that hardware installed on those machines; and
  c) examine if the same motherboard is used for a particular machine.
  
     Perhaps there is a driver that's spending a good bit of time in an interrupt handler somewhere either out of necessity or perhaps less than optimal design.  Also, there may be hardware requesting a bit more interrupts than it requires.  Not all hardware/drivers are created equal (nor how the motherboard itself relays the hardware to the CPU).
  
     I may be way off base with my suggestion that it may be a low-level driver/hardware issue, but it does seem delay can be introduced at a level that isn't necessarily apparent to the OS (aside from drivers).  I've seen early motherboards designed for a multiprocessor system actually run applications much slower than the single CPU motherboard.
  
  Regards,
  
  Joe
  

• James V

  Hi dk,
  
  As you said the Threading.Timer is used to get an interval.
  
  

  private void TimerOnTick(object obj) {

     this.Time = DateTime.Now;  //this.Time is a DateTime method within the class that does the graphics.

  }

  public void startStopTime(bool sst) {

  if(sst){

  // Create the delegate that invokes methods for the timer.

  TimerCallback timerDelegate = new TimerCallback(TimerOnTick);

  clkReady = true;

  clkTick = 0;

  this.timer1 = new System.Threading.Timer(new TimerCallback(timerDelegate), null, 0, this.ClockSpeed);

  }

  else {

     if(this.timer1 != null){

        this.timer1.Change(System.Threading.Timeout.Infinite,
                                             System.Threading.Timeout.Infinite);

       }

     clkReady = false;

  }

  }
  
  There is more, but I do not want to get into the details as this code has been checked out by Microsoft.  And I am fairly sure the problem is not in the code but rather the environment.
  
  Any other hints
  
  

  
  

• GT_MSDN

  oops!!..sorry about my outbust of steam in my last posting. It was a late night. 
  
  Thanks Joe for posting. It's great to get some response.
  
  I thought it might be hardware, but the computers I have tested vary as follows:
  This is the email I sent to Microsoft.
  

  ----------------------------------------------------------------------------
  Dear Engineer,

  Case Number:
  
  I have a problem with the System.Threading.Timer class (at least I think it might be this class) that I am using for my C#.NET analog clock program. The clock runs faster on some boxes than it does on others ie Intel box or AMD box.

  I have developed a smaller version which experiences the same problem and is attached. The start button will start the clock and the Bounce button will bounce the clock. Once you have hit the start button just hit the bounce button a few times. Then close the app and start again. To see the effect you need two different computers and click the buttons at the same time to see the marker move.

   

  Here are my results:

  1) Mobile Intel Pentium 4M, (Windows XP), 1733MHz(5x347) IBM Thinkpad laptop with ATI Mobility RADEON 7500 Video card - Woks fine

  2) AMD Duron XP, (Windows 2000), 1000Mhz(5x200) with Trident CyberBlade-i7 - works fine

  3) Mobile Intel Pentium IIIE, (Windows 2000), 1000MHz(10x100) with S3 Graphics Savage/IX 1014 video card - Works fime

  4) AMD Athlon XP-A, (Windows 2000), 1100MHz(5.5x200) with NVIDEA GeForce4 MX440 with AGP8X video card - Runs slow

  5) Intel Celeron 4A, 2400MHz(6x400) and onboard video SIS 315 - Runs Slow

  6) I have details of another box an old Dell Optiplex that works as well. Let me know if you need the specs for this.

  I thought maybe it could be a video card problem, but can't see any problems out there of this kind.

  Would be great if you could point me in the direction of what it might be to run slow on one box and not another

  I have attached the .exe file and the C# code file.
  
  
  ------------------------------------------------------------------------
  
  By the way the Dell Optiplex (no. 6) is a PII 300MHz with onboard ATI Tech 3D Rage Pro AGP.
  
  As you can see the computer hardware varies and note computer 4 runs slow whereas 6 runs ok. 
  
  

  
  

• Andrej Ruckij

  Uhm... Vijaye was correct.  Use the Timer to TELL your clock to update.  Use the system time to get the time.
  
  

• sjcrichton

  THanks for the posting dk.  Yes, I am using the timer to tell my clock to update and I am using the DateTime.NOW to get the time.  Just like Charles Petzold described in his book "Programming Microsoft Windows with C#".  However, I don't think Mr Petzold considered using it in conjunction over many computers at the same time when he designed his clock.   
  
  Still looking for a hint.
  
  regards
  
  

  
  

• Andrew Chapman

  Thanks dk, I will look at that option.  Another thought is that I might insert some code to do some timing checks on the processing of the display code.  If I then check these for the machines that are running normal against the machines that are running slow I may find something.
  
  I will leave this thread open for the moment in case anyone else may want to add a hint or suggestion.  Remember, hints or suggestions do not have to be accurate as brain storming is just getting ideas out there.
  
  
  

• Robert.Jack

  Sorry Joe, in relation to your question the clock runs fine and I am able to vary the speed by changing the timer.  The clock in the slow machine (or correct speed - not sure if the fast clock or the slow clock is the correct one) also runs fine and smoothly.  The actuall speed of the clock doesn't bother me too much, but I would like it to be approx the same on most computers.
  
  cheers
  

• Robert Accettura

  If you're using DateTime.NOW to get the time, then how are you "hav[ing] a problem with the System.Threading.Timer class"   I'm confused.  Can you post a short example that demonstrates the problem
  
  

• r1zky

  Thanks for posting.  It does not need to be accurate for my case as long as it moves roughly the same speed on multiple computers.  I do not believe the threading or paging is a problem here.  I am investigating the impact of video cards as they can draw resources from the cpu. Microsoft are looking into it, but they don't seem to have an answer yet.  So far, I have tested 6 different machines with varying cpu speeds and video cards.  It is not related to the cpu speed and does not seem to be related to the video card.  I am now trying to think of anything else. Like perhaps the service pack.  I am using the drawing2D class as well in this.
  
  Any other suggestions out there
  

• iscbaltazar

  So is DateTime.Now returning a time that is not the system time, or is the system clock somehow running slower when your code is running   I can't imagine the latter unless MS is messing with the clock setting inside their code. 
  
  If you are running on a machine that has an Internet connection you could try getting the time from a Web Service.  I believe there are some out there.  Hope this helps...
  
  

• tim00

  You can't construct a clock using the Timer class and expect it to be accurate.  Timers are only approximate - their firing interval depends on a ton of factors, like thread scheduling, paging, etc. 
  
  You can use a timer to redraw your clock - but you might want to fetch the system time from time to time to correct your clock.
  

• Slybacon

  Greets,
  
     I still have to ask, is it just that your clock is updating slowly or is it actually keeping incorrect time   Note: if it is just in the speed in which your analog clock updates (i.e., second hand doesn't sweep as smoothly) then I would still take a look at the hardware.
  
     Even though you may add your own checks to the time from the beginning to the end in your code, you still cannot account for all of the hardware interrupts that may have occurred on a particularly 'slow' system that may have inhibited your video driver updating your display.
  
     It may be something as simple as updating a video driver or just replacing horribly designed hardware.  Even still, it might be choosing a decent motherboard.  Again, I'm only making a guess here, but it smells like it's a hardware issue.
  
  Regards,
  
  Joe
  

• willis3000

  Well folks, I found something on my search.  I will keep looking.  This is an extract from a C# tutorial:
  
  ......introduce the Pen and the Brush objects. These objects are members of GDI+ library. GDI+ or GDI.NET is a graphics library that lets you draw on a form. Prior to .NET, C programmers were using GDI library to create breathtaking graphics. GDI.NET is in fact just a wrapper for GDI. GDI+ is a great platform for moderately complicated static graphs. However, it tends to be slow for moving images and not sophisticated enough for 3 dimensional graphics. On Windows NT platforms, GDI+ as well as GDI do not perform very well. The problem lies in the way GDI/GDI+ runs. Windows NT architecture accepts user input in so called user context and access graphics devices in system context. When GDI/GDI+ application runs on Windows NT based machine, it has to constantly wait for these context switches to occur. This makes GDI/GDI+ applications too slow for video game programming and fancy 3 D graphics. Microsoft recently released a highly optimized graphics platform - Managed DirectX.......
  
  
  Hmmm...could be a clue..still looking....

  
  

• mciv34

  Well I have some more interesting news on this one.  I inserted the time checks from when the clock starts to its first stop point.
  
  All the delays (nano seconds - nS) for the working computers are approx the same and all the delays for the slow computers are approx the same.
  
  ie ~ 16,000,000 nS for the working and ~ 20,000,000 nS for the slow.  Or it could be the other way around. ie the correct working speed could be the slower time.
  
  This has me a little dumb founded.  Microsoft has said that I should change the code to C++ to increase the efficiency and mentions links about timers(which are the basic ones).  They have been no use.  I sent the rep looking after me the small snippet of code and the exe file and they didn't even test it before they gave me there standard reply.  You would think that Microsoft would be interested in issues affecting there O/S.
  
  Changing the code will do no good in solving the delay difference between the different computers.  And the difference is the same for all the computers that are running slow(regardless of their video cards or on board video or CPU speed).
  
  Talk about frustration!
  
  Thanks to those who have commented so far.  Any one else feel free. You can even comment about Microsoft's help service if you like...:o)
  
  
  
• C# analog clock runs slow on some computers