Differences are as follows:
SBI-7425C-S3 : onboard SAS controller
SBI-7425C-T3 : onboard SATA controller
SBI-7425C-S3E : onboard SAS and onboard Infiniband (this blade is only supported on our just released blade enclosure SBE-714E Enterprise Blade enclosure)
The Enterprise Blade supports 14 blades, Infiniband, 2x 10Gb or 1Gb switch