3-4x slowdown in performance between 1.6.5 and 1.8.1

Hi All,

I am wondering if anyone else can confirm this.

I have customers who have for a long time used HDF5-1.6.5. They recently
switched to 1.8.1 and are seeing a 3-4x slow down in I/O performance to
files in lustre filesystems. Note, I am talking about ONLY serial HDF5
here, not parallel. There is also a slowdown to standard ext3 and nfs
filesystems but not as pronounced.

Is anyone aware of any known, serious performance issues with 1.8.1?



Mark C. Miller, Lawrence Livermore National Laboratory
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