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?

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.

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. :)

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

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.

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.