Database test: 8-way Opteron

One can write long stories on the differences between Solaris and Linux, and the virtual infinity of the internet means that some people will in fact do just that. For instance, Dr. Nikolai Bezroukov has made a fundamental comparison listing advantages and disadvantages, but also the history and mutual influences. His conclusion is, in a nutshell, that Solaris has a lot of interesting features and is ahead in terms of architecture in a great deal of areas, but at the same time its commercial character - which has diminished but is still present - prevents it from enjoying the same name recognition as Linux. One of the claims being made is that Solaris scales better than Linux, especially where multithreading and open source databases are concerned. Our previous experience confirmed this hypothesis of Bezroukov: PostgreSQL ran 6% better on a double 2.4GHz Opteron and MySQL did 14% better than Linux.

When four or eight processors are used to compare Solaris and Linux, we see mixed results. There were already a few somewhat disappointing scores to be digested running MySQL 4.1.22 under Linux, moreover, these went down considerably with the transition from four to eight Opterons. The behaviour is different under Solaris: the peaks with small numbers of users are markedly higher than they are under Linux, but as soon as the load increases, performance diminishes quickly here, while under Linux this does not happen until the eight processor mark. Whether this is a good or a bad thing depends on the situation at hand, but actually neither of the two options look very favourable.


Under Linux, MySQL 5.0.32 behaves a good deal better than MySQL 4.1.22, but under Solaris it still exhibits strange behaviour. With four processors, the Solaris version beats the best results obtained under Linux (including the one with eight processors) but makes a poor showing on further upscaling, by falling back almost a quarter.

Scaling favourite PostgreSQL 8.2-dev behaves in an odd fashion: performance is virtually equal with four processors, but the Linux version wins 24% on the transition to eight processors while the Solaris version drops by 10%, allowing Linux to reach the finish line with a 38% advantage. It must be said that at Tweakers.net, we have a great deal more experience with Linux than with Solaris, but we do not think that the strange behaviour in the various databases can be attributed to spurious configurations: the installation of Solaris was done by people from Sun itself, and they subsequently provided us with a number of tips and tricks. A final check performed by Tweakers.net and Sun did not bring up an explanation either, but Sun will continue to look into the matter.