[plt-scheme] Appalling performance of DrScheme on Windows

From: Jens Axel Søgaard (jensaxel at soegaard.net)
Date: Tue Jun 20 01:20:47 EDT 2006

 > On Jun 19, 2006, at 6:31 PM, wooks wooks wrote:

 >> I am running DrScheme on Windows XP and I regularly experience
 >> abysmal response time running DrScheme.
 >> Usually its starts off ok but the longer its left running the worse
 >> the response time gets (especially if you leave a session idle for a
 >> long time). It is not uncommon for me to manage only 4 interactions 
 >> in an hour because DrScheme just hangs for ages before it will 
accept >> input.

wooks wooks wrote:

> 1. I am running a 1.3GHZ Celeron processor with 248MB of RAM (is that 
> the info you wanted).
> 2. DrScheme 301
> 2a Apart from installing the SimplyScheme teachpack - no (we've 
> discussed this before).
> 3. Just working my way through HTDP - on chapter 11 at the mo.

The key issue is RAM. Your computer is fast enough, but could
have more memory.

If Windows needs to swap it can be problematic - I have
experienced that in other programs than DrScheme on faster

Some thoughts:

  1. Do you happen to run other programs that use a lot of RAM?
     (On my computer Firefox eats a *lot* of RAM - especially
      the newer versions)
     Close them before starting DrScheme.

     PS: Can you make a screen dump of the "Job list" sorted
         after memory usage the next time a slow down occurs?

  2. Try DrScheme3m and see if there is a difference. There
     might be if you, like me, never closes DrScheme.

  3. Follow the advice from Microsoft for optimizing the swap file.
     * same initial and maximum size
     * defragment the drive with the swap file after resizing it,
       to make sure it is one continuous file.
     - at least twice the size of RAM (but make it times 4 or times 8)
     - place the swap file on a fast disk
     - place the swap file on a non-system disk (i.e. not C:)

  4. If you experience the slow down, then the cure is simple.
     Close DrScheme and open it again. It doesn't help to close
     and reopen tabs.

  5. Ad laptops after wakeup: Any problems are most likely still
     swap - Windows doesn't swap the entire program in at once.
     If the problem persists: Close and restart DrScheme again.

  6. Buy more RAM. It is money well spent.

Happy Scheming,
Jens Axel Søgaard

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