2405 vs 5405z - Write Cache with BBU?

[stateless]

Putting together a basic 1U colo system for ESXi.

• Supermicro 5016T-MTF
• Xeon E5620
• 12GB RAM
• RAID10 - 4xSeagate Constellation ES SAS

I'm trying to decide between the 2405 and the 5405z. The 5405z is a 5405 with a BBU, there is no BBU option for the 2405. Both units are in the ESXi HCL, but my understanding at the moment is that raid monitoring for either the 2405 or 5405 is not straight forward. The 5405z is about 3x the price of the 2405.

How important for ESXi is the write cache in RAID10 mode? Does the 2405 have a write cache mode, even without the BBU? If the write cache is used without a BBU is this likely to cause issues with ESXi?

 

[archivalbackup]

Write cache makes a huge difference in write latency, and can reduce read latency by waiting to write until the disks are idle. If you use write cache, IMHO you must have a 72 hour battery backed cache, and UPS's on top of that. Write cache should be programmed to disable anytime the batteries fall below charge threshold.

I am not a big fan of SuperMicro in general, but that's past experience.