I might actually retract my results above.
The VM's I was running the tests on were ones I'd set up under VMware ESXi 3.5 update4. That version of VMware does not have any pre-sets for FreeBSD.
Today, I rebuilt my FreeBSD 8.0 VM from scratch, under VMware ESXi 4 Update 1. This time using the FreeBSD (64-bit) pre-set that's now available.
My results are currently averaging the following:
FreeBSD 8.0 built under ESXi 4- 910Mbit/ network throughput
- 19MB/s disk write speed
Apologies if this is now distracting for the topic, I just wanted to clear that up.