Response time at a computer

imageThere are tons to read about performance with computers on internet. Milliseconds, latency, priority, MBS, IOPS, paging, CPU%…
I can’t name them all. It is a science in itself.

But there would have been no performance issues what so ever, if nobody have had the guts to complain. So performance problems is about expectancy – expected service compared to received .

image I do this as I always I have done, and now the silly “thing” don’t let me go on, because it is busy doing something else compared to what I am used to. This is the situation where frustration is born, and some of us get so irritated that we complain, and then it sooner or mostly later becomes an issue, called a “performance problem”.


Problem? The response time in any computing situation could be split up in two parts, service time and queuing time.  The service time is what it takes to do what I ask for, which means some time with the CPU, and the time it takes for the disk to get or store some data and it may also include the time involved in getting or updating some information in another computer. There are basically three resources you ask for: CPU, some disk activity on your own computer and some activity from “out there”. If I always was priority one I would always have the same response time = service time, the time it takes for those silly machines to do what I asked for, i.e. what you expect most of the time. But what you always get is service time + queuing time, someone else seems to be more important than you are. So for one reason or another – you have to wait in some of these queues… So analysing performance problems, is analysing queues and waiting situations. In some cases it could be attacked by shrinking the service time, since all programs could always be improved in some way.

Could such analysis then be done by a silly computer? My first answer would be no. But I might be wrong… There are tools that work with both issues. If someone who knows how to analyse stuff like this could explain what they do, then it might be possible to at least make my own computer a useful tool helping to solve these types of issues, AI as it is called. The resources to investigate are only three, my own CPU and disk, and then these strange computers outside my desk. Find the reason and then apply corrective action, the first one is often the most tricky.

If your car is broken, and you just leave it and say, “There is a problem”… You give no explanation on where or why, you give the guy solving this problem a lot more to do… If you say “I have trouble with the windshield wiper when I push this button and this occurs…”. Then you have defined the problem much more narrow, and probably it is fixed when you pick up your car.

imageThe same story is true about response time problems, if you just say “I have a problem”, that might not be helpful enough to solve it. But if you instead say I have a problem with my disk, it don’t do what it has done earlier, you will give the guy you ship it to a much easier job. Or if you just hint him on that this problems occur when I do this… And then nothing happens, and it only happens when I visit this site on internet…

So – helping the guy trying to help you is always win – win!!