Dell just started shipping the "mark ii" 9-series boxes capable of taking the new quad-core Intel Xeon processor.
Unfortunately the older 9th generation are not compatible with the new quad core processors. Intel made some last minute design changes to the new chip that required Dell to revise their motherboard designs.
Look out for a "II" symbol on the front of your 9th gen boxes.
Quad-core will be available on the SC1430, 1900, 2900, 1950, 2950 and the 1955 blades.
Performance is said to be up to 60% better than a dual core system, which sort of puts 2-socket machines in "enterprise territory" for the first time. Sure, we got the 8-core Sun T1, but that is a quite niche market machine.
A 8-core Dell PowerEdge 2950 with dual quad core procesors, 8Gb RAM and a pair of 72Gb SAS disks costs just under £6000 ($10kUSD).
I'd love to do some JBoss benchmark on a mk2 1950.