Hardware and Software Compatibility List.

[BadIntentions]

http://patriotmemory.com/software/javelin_s4/Javelin-S4_Compatibility_List_V1_0_%20-20110701.pdf

The S4 has been tested with a large array of hardware, software, and remote devices. The PDF above goes into more detail.

[Patriot_Ben]

Seagate Barracuda LP 2TB SATA 6GB/S 3.5IN 12MS 5900RPM 64MB Hard Drive also confirmed (Credit seadooxp30)
http://www.patriotmemory.com/forums/showthread.php?8362-Seagate-Barracuda-LP-2TB-SATA-6GB-S-3.5IN-12MS-5900RPM-64MB-Hard-Drive

[HansSchulze]

Western Digital 2TB and 3TB SATA work well.
WDC WD30EZRX-00MMMB0 FW:80.00A80 Capacity:2794.52 GB
WDC WD20EADS-00S2B0 FW:01.00A01 Capacity:1863.02 GB
WDC WD20EARS-00MVWB0 FW:51.0AB51 Capacity:1863.02 GB

The following drive does not work well, causes timeouts on startup:
WDC WD2500KS-00MJB0 FW:? Capacity:250 GB

[Reverend]

Hitachi 4TB drives work without issue:

Hitachi HDS724040ALE6

[karl_jay]

It helps a lot!