Decreasing performance of dev machine to match end-user's specs

I have a web application, and my users are complaining about performance. I have been able to narrow it down to JavaScript in IE6 issues, which I need to resolve. I have found the excellent dynaTrace AJAX tool, but my problem is that I don't have any issues on my dev machine.

The problem is that my users' computers are ancient, so timings which are barely noticable on my machine are perhaps 3-5 times longer on theirs, and suddenly the problem is a lot larger. Is it possible somehow to degrade the performance of my dev machine, or preferrably o开发者_运维技巧f a VM running on my dev machine, to the specs of my customers' computers?

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I don't know of any virtualization solutions that can do this, but I do know that the computer/CPU emulator Bochs allows you to specify a limit on the number of emulated instructions per second, which you can use to simulate slower CPUs.

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I am not sure if you can cpu bound it, but in VirutalBox or Parallel, you can bound the memory usage. I assume if you only give it about 128MB then it will be very slow. You can also limit the throughput on the network with a lot of tools. I guess the only thing I am not sure about is the CPU. That's tricky. Curious to know what you find. :)

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You could get a copy of VMWare Workstation and choke the CPU of your VM.

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With most virtual PC software you can limit the amount of RAM, but you are not able to set the CPU to a slower speed as it does not emulate a CPU, but uses the host CPU.

You could go with some emulation software like bochs that will let you setup an x89 processor environment.

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You may try Fossil Toys

* PC Speed
  PC CPU speed monitor / benchmark. With logging facility.
* Memory Load Test
  Test application/operating system behaviour under low memory conditions.
* CPU Load Test
  Test application/operating system behaviour under high CPU load conditions.

Although it doesn't simulate a specific CPU clock speed.