It may work but its not on the HCL for ESXi 4.
http://www.vmware.com/resources/compatibility/search.php
If you do have a problem and you call into VMware they may not support you. I have tried ESXi 4 with a PERC 6/i controller and it installed fine but would not boot after the install.
david
PERC 5i - internal SAS/SATA RAID controller
PERC 5e - external SAS/SATA RAID controller (in Dell used for connecting MD1000 or MD3000)
PERC 5i is very similar to PERC 6i (newer generation). The difference is that PERC 6i has memory integrated on the card and supports additionally RAID 6 and 60.
I have installed ESX 4 on PE2950 with PERC 5i (2 disk in RAID1) without any problems.
Good luck
Onsik
Following your suggestion......
I've just got 2 DELL PERC 5/i + BBU and 512 MB (Ebay €. 110,00 each one)
I've plugged in my ML115 G5 Quad Opteron with 4x 2048 MB Corsair DHX Dual-Path DDR2
Plugged 4 sata cable to 4 x 500 GB Barracuda
Switched on
2 minutes for configuring RAID (created only one datastore with max capacity available with speed format)
Booted with my ESXi 4.0 Build 164009 from my USB Pen Drive
System has been recognized immediatly (it seems that storage attached to PERC is Parallel SCSI even if it is SATA)
Now it's time to upload some vm's
Ciao.