Q: Passage: Servers: The VRTX chassis has 4 half-height slots available for Ivy-Bridge based PowerEdge blade servers. At launch the PE-M520 (Xeon E5-2400v2) and the PE-M620 (Xeon E5-2600v2) where the only two supported server blades, however the M520 was since discontinued. The same blades are used in the M1000e but for use in the VRTX they need to run specific configuration, using two PCIe 2.0 mezzanine cards per server. A conversion kit is available from Dell to allow moving a blade from a M1000e to VRTX chassis.

Question: Based on this passage, how many half height server modules can poweredge vrtx support?
Let's give stream of consciousness below
The important part for answering this question is: Servers: The VRTX chassis has 4 half-height slots available for Ivy-Bridge based PowerEdge blade servers. So the answer is 4.