Re: Lilypond Speed

[Peter Chubb]

>>>>> "Han-Wen" == Han-Wen Nienhuys <address@hidden> writes:

Han-Wen> On Mon, Aug 31, 2009 at 8:03 PM, Peter
Han-Wen> Chubb<address@hidden> wrote:

>> I think you'll find the main difference is in size of L2/L3 cache,
>> and amount of RAM.  Lily (like many object-oriented programs) tends
>> to have quite a deep stack, and to use lots of memory --- which it
>> visits in what looks to the processor like random orders --- so
>> small caches generate lots of cache misses, which slows things
>> down.  If you run out of RAM and have to swap, things get even
>> worse.

Han-Wen> More importantly: LilyPond is single-threaded, so the number
Han-Wen> of cores is irrelevant.

That doesn't explain why going from the Core Duo to the Xeon
dropped the time from 11 minutes to 4 minutes.  The reason, as I said,
is the increased cache size.

--
Dr Peter Chubb          www.nicta.com.au    peter DOT chubb AT nicta.com.au
http://www.ertos.nicta.com.au           ERTOS within National ICT Australia