Looking forward to OpenOffice 2.1
Performance Gain of Factor 15 to 40
I knew the headline would draw your attention 
I’d love it (and you’d love us) if these numbers were for the entire application suite, but totally unspectacular they’re for the import of huge formula loaded MS-Excel documents into Calc, which is nice enough to be delighted anyway.. Down on the floor and back to the facts: when loading a quite big Excel document, I’m referring to 25 MB of size, more than 100 sheets, a million cells and hundredthousand formulas, formula cells unnecessarily broadcasted their initial recalculation state to all dependents. Building up this dirty tree took most of the time and by replacing it with a document wide simple chain mechanism for this case, loading times went down to a fraction. The metrics from two different machines for that document are:
Small one processor system: model name : Intel(R) Pentium(R) 4 CPU 1.80GHz cpu MHz : 1816.213 cache size : 256 KB bogomips : 3617.58 Mem free : 386488 kB (or somewhere near that) old performance : 39:08 minutes new performance : 2:37 minutes performance gain: factor 15 Two dual core processors system: model name : Dual Core AMD Opteron(tm) Processor 275 cpu MHz : 2194.038 cache size : 1024 KB bogomips : 4393.64 Mem free : 3388412 kB old performance : 27:58 minutes new performance : 0:43 minutes performance gain: factor 39
This is from issue 68960, targeted to OOo2.1
Taken from this blog post.