[R-SIG-Mac] performance difference GUI vs. terminal

[Simon Urbanek]

Joerg,

thanks you for the report.

On May 19, 2005, at 7:58 AM, joerg van den hoff wrote:

> I upgraded today from 2.0 to 2.1.0a on my G5.
> I'm using still mostly the command line interface to R, but of course
> the GUI is attractive, too, and better access to the quartz()  
> device is a big plus (I would of course say a BIG thank you to the  
> people who are engaged in this).
>
> but (as I already noted  under 2.0) there is a rather big  
> difference in performance when initiating the same calculations in  
> the GUI and the terminal, respectively.

You are right. Closer look at the issue using your example reveals:

in the GUI (2.1.0a release):
 > system.time({ sum <- 0; for (i in 1:1000000) sum <- sum+i })
[1]  5.50  1.34 10.41  0.00  0.00

console:
 > system.time({ sum <- 0; for (i in 1:1000000) sum <- sum+i })
[1] 3.00 0.06 3.35 0.00 0.00

As you can see the CPU running the GUI is not spent in R but  
somewhere else. Basically it gives other applications and/or system  
too much time (the disk use you mentioned is simply some other  
application than R). I have now changed the GUI such that it won't  
call the event loop too often. The timings improved indeed:

GUI (r1545):
 > system.time({ sum <- 0; for (i in 1:1000000) sum <- sum+i })
[1] 3.15 0.09 3.52 0.00 0.00

It's still slightly slower, because I'm using single-CPU machine and  
it has to handle user events, but the difference it not as big.  
Please fetch tonight's nightly build (1545) to get this speed up and  
tell me whether it works for you.

Cheers,
Simon