CF 2021 slower than 2018?

Anyone find CF 2021 slower than 2018? I’ve tested apps running on CB4.1 so far, and found it on average almost 100% slower.

Nick, no. Definitely not. If anything, it has been faster.

There are SO many reasons you could experience pages being “slower” which could not have to do with CF itself, but your configuration. Here are at least a few questions to start to guide you to a solution:

  • are you saying you’ve confirmed this fastness of CF2018 and slowness of 2021 on the same machine/server?
  • have you confirmed the slowness of CF2021 by running it on some other machine/server?
  • have you configured the CF2018 and 2021 instances similarly, in terms of admin settings and especially the heap size?
  • are you fronting CF with a web server like IIS or Apache? Which, and using what means to connect it to CF? Do you get the same slowness if you call a page using CF’s built-in web server instead?
  • you indicate having used CommandBox. You could consider implementing CF some other way (on the same box), whether the full installer or the new CF2021 zip option, or using the Ortus or Adobe CF Docker image
  • if somehow none of the above help, then rather than guess at still more possibilities, have you used any sort of tool to diagnose WHERE the slowness is in the page request? FusionReactor can help here (free 14 day trial). Brad will be speaking on getting started with it on the Online CFMeetup this week

Thanks for the reply.

They’re on the same server, running on two different virtual machines with exactly the same specs. Both virtual machines were cloned from the same virtual machine that was running CF11. We simply upgraded one to CF18, and another to CF21.

I’ve checked and compared the CF settings, and tweaked them to be as similar to each other as possible. The min/max heap sizes are exactly the same.

Have you tested on both 18 and 21 and can confirm that 21 is equal or faster?

Again, yes I have. CF2021 has been faster in all tests, comparing identical code on the same machine, whether using commandbox or the full CF installer, and whether using an external web server like IIS or using CF’s built-in web server.

But I realize that won’t mean much if you feel you’re always seeing CF2021 being slower. And in that case, I stand by my last comment: you should get FR to know WHERE the time is (if indeed it even is in CF).

And I can help with that, if interested, via consulting ( You won’t pay for time you don’t find valuable. But perhaps your focus for now is just to see if others might confirm they’re seeing the same slowness as you. Let’s see.