Ok, first I'm pleased to say I've a telephone conference with an  
engineer at apple next week to discuss drawing performance issues.

Second: In the Apple MacIntel universal binary compatibility  
document  we find:
"Tip: The best solution is to convert your QuickDraw code to Quartz  
2D. QuickDraw was deprecated
starting in Mac OS X v10.4. For help with converting to Quartz 2D,  
see Quartz 2D Programming for
QuickDraw Developers."

This is a clue/command from Apple to convert to the quartz drawing  
environment going forward for applications that want to run
natively on MacIntel.

The 3.8.6b1 VM uses quickdraw and was tuned to reduce screen  
flushing, see a 3.8.5b1VM for how dismal the hilbert code could run.

Now a major complaint over the years is that os-x quartz drawing is  
slow as compared to os-9, this is show in your numbers of 7.8 versus 6.5
Apple's response is that Quartz extreme will address those problems,  
or you should use Open/GL for drawing.

As for picking which code to run based on operating system versions,  
this could be done, it makes support a bit harder, and for now I'm  
waiting to
see what apple says about our drawing problem.

On 18-Aug-05, at 12:53 PM, Tom Phoenix wrote:

> On 8/18/05, John M McIntosh <johnmci at smalltalkconsulting.com> wrote:
>
>> I've posted a mac vm 3.8.8b9
>>
>
>  10 timesRepeat: [Transcript show: (Time millisecondsToRun: [
>      | b |
>      b _ Pen new.
>      Display fillWhite.
>      b place:(Display boundingBox bottomLeft).
>      b hilbert: 7 side: 2]); cr]
>
> This runs in about 7.8 seconds per iteration. But it only takes about
> 6.5 seconds to run under 3.8.6Beta6. Is that because of the
> unavoidable changes, or is there some way to let machines which can
> run the older code do so?
>
> --Tom Phoenix
>
>
>

--
======================================================================== 
===
John M. McIntosh <johnmci at smalltalkconsulting.com> 1-800-477-2659
Corporate Smalltalk Consulting Ltd.  http://www.smalltalkconsulting.com
======================================================================== 
===