MySQL on Solaris faster than on Linux?

Yahoo reports that MySQL on Solaris is faster than on Linux.

SANTA CLARA, Calif., April 21 /PRNewswire-FirstCall/ -- Sun Microsystems, Inc. (Nasdaq: SUNW - News) today announced new benchmark results involving the performance of the open source MySQL database running online transaction processing (OLTP) workload on 8-way Sun Fire(TM) V40z servers. The testing, which measured the performance of both read/write and read-only operations, showed that MySQL 5.0.18 running on the Solaris(TM) 10 Operating System (OS) executed the same functions up to 64 percent faster in read/write mode and up to 91 percent faster in read-only mode than when it ran on the Red Hat Enterprise Linux 4 Advanced Server Edition OS.

"MySQL and Sun have worked to optimize the performance of MySQL Network software certified for the Solaris 10 OS," said Zack Urlocker, vice president of marketing for MySQL AB. "This benchmark demonstrates Sun's continued leadership in delivering a world-class operating environment that provides excellent MySQL performance for our mutual enterprise customers."

I wonder if it means there were some changes to MySQL so it runs faster on Solaris?
In our internal tests MySQL on Linux (however older MySQL versions) was actually slightly faster than on Solaris - maybe we should re-check it. Unfortunately not much info on actual system tuning and disk config is reported (was ZFS used? how much IOs were generated, etc.).

Actual benchmark is here and official Sun announcement here.