I am involved with the development of a Windows application that has various screens. One of them takes ten seconds to appear with no spinner or other indication that the screen is loading. I consider this a serious performance issue but I seem to be the only one who is concerned.
Am I being overzealous? What is an acceptable amount of time to wait for a screen to appear?
This is old research but 10 seconds is bad:
http://www.useit.com/papers/responsetime.html
from the page:
The basic advice regarding response times has been about the same for thirty years [Miller 1968; Card et al. 1991]:
•0.1 second is about the limit for having the user feel that the system is reacting instantaneously, meaning that no special feedback is necessary except to display the result.
•1.0 second is about the limit for the user's flow of thought to stay uninterrupted, even though the user will notice the delay. Normally, no special feedback is necessary during delays of more than 0.1 but less than 1.0 second, but the user does lose the feeling of operating directly on the data.
•10 seconds is about the limit for keeping the user's attention focused on the dialogue. For longer delays, users will want to perform other tasks while waiting for the computer to finish, so they should be given feedback indicating when the computer expects to be done. Feedback during the delay is especially important if the response time is likely to be highly variable, since users will then not know what to expect.
More than two seconds without an hour-glass and I'm already pretty skeptical. Different people will have some different expectations but I would expect 10 seconds with no feedback to even acknowledge that I clicked a button or whatever would annoy almost anyone. Whether or not it matters to annoy your users is another question.
What do the intended users of this application think? If they're OK with it, then don't worry. Some applications that have to process lots of data, it's OK for a window-open command to have a bit of a delay before opening.
If it's possible to add a splash screen or a progress bar or something to indicate to the user that it's working that would be good. I usually try to add a progress indicator of some sort if my testing shows that a window regurlarly takes more than 2-4 seconds to appear.
We stick by a rule that it should take no more then 2 seconds for ANY feedback to appear for the user.
I said any feedback because there are times when it is not possible to load up the entire page within 2 seconds. You have to let users know what to expect after first 2 seconds.
Although DKnight cites good research in his answer, another thing to consider would be the performance requirements of the system. Are the users doing some kind of time-sensitive work or for some reason need quick requirements? If you can somehow ask the users what response times they would like to see, especially in terms of minimally acceptable times, that would be best. Performing usability testing with observation would also be good for overall usability, and if you see a user getting frustration with waiting after performing a specific action, then you know to revisit the performance of that portion of the system.
In terms of generalities, though, I would suspect that 10 seconds is indeed a long time. There are some long-running operations, and if this is indeed the case, it is important to provide cues to the user that the system is still working and to continue waiting.
I agree that 10 seconds are definitively too much. I worked for intranet applications in a Software House (used only internally by employees) and maximum delay while loading a page was 5 seconds. This was for me the limit.
However I saw other internal application, very complex indeed, but where loading time was something dramatic. In the worst situation, due to thousends of records/queries executed it took around 2 minutes! But this is of course too far away from the general context.
Therefore I would conclude saying that 3 or 4 seconds are the limit for providing a good response service.
This is not a performance issue as such, but a GUI issue. The user should be TOLD what the program does and if it takes longer than 1-2 seconds, a progress bar should be displayed.
That said, there might be a REASON for this, if it used to be fast, but that is not what you asked.
The typical problem with such applications is running out of physical memory so Disk I/O becomes the bottleneck for loading and swapping. It might also simply be that the datasets have grown so big that the O(N^3) algorithm now shines through.
