For what it’s worth…
When the Sun T2000s were released we did a performance comparison between our current platform, a Sun V240 (twin UltraSPARC IIIi 1.5 GHz) and a T2000 (T1 8 core 1 GHz). This was about 2 years ago.
At the time we were running IS 6.5 SP1 on JVM 1.4. (I didn’t do any Broker tests.)
The test I ran on both platforms was to open a flat file from the filesystem, transform it to XML, then convert it back to the same flat file format and write it out to the filesystem. I used 5k, 66k, 150k, and 480k sized flat files, and also varied sequential vs parallel vs different numbers of parallel. (For those interested, I used JMeter to trigger the services and capture results.)
Generally across the tests the T2000 performed better than the V240 - with some exceptions. As the file size increased the performance difference narrowed. In the case of the largest file, at sequential or two processing in parallel the V240 was better (more GHz). At 4 in parallel the platforms were even, at 10 the T2000 was better.
This shows that 2 cores at 1.5 GHz does better at a few big jobs than 8 cores at 1 GHz. And 8 cores at 1 GHz handles lots of little jobs better, but slows down as more grunt is required (transformation of increasingly larger files). Which gels with what swl stated.
THEN… it was recommended I try the 1.5 JVM (which at this point wasn’t supported by wM).
I re-ran the same tests. With the 5k and 480k files average processing time was cut by a third, and with the 66k and 150k files average processing time was halved.
Given that this question is about the T2… a quick reading of the spec.org SPECjbb2005 benchmarks points to the T2 having a little over double the performance of the T1 with regard to Java processing - I’d like to re-run the same tests again on a T2 to get some hard figures.