<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=us-ascii">
<META content="MSHTML 6.00.6000.16890" name=GENERATOR></HEAD>
<BODY>
<DIV><FONT face=Arial size=2><SPAN class=884391312-10112009>Hi
Dean</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=884391312-10112009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=884391312-10112009>In tests we've done
at BADC we have experienced 10-20x slowdown in write speed with NetCDF4
compression. Is this typical and are modelling centres aware that they can
expect a significant I/O bottleneck?</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=884391312-10112009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=884391312-10112009>This makes me think,
have we said CMIP5 data *must* be compressed? Is there a danger we will
get a higher volume of data than we expect because it will be uncompressed to
speed up the process at the modelling centres? How would we enforce NetCDF
compression -- presumably it would be discovered during
replication.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=884391312-10112009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN
class=884391312-10112009>Cheers,</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=884391312-10112009>Stephen.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV align=left><FONT face=Arial size=2>---</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>Stephen Pascoe +44 (0)1235
445980</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>British Atmospheric Data
Centre</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>Rutherford Appleton
Laboratory</FONT></DIV>
<DIV> </DIV>
<br><p>--
<BR>Scanned by iCritical.
</p>
<br></BODY></HTML>