I've installed the G-SPEED eS card, installed the drivers but the speed seems to be slow
Depending on your MacPro's slot speed settings the speed results can very, this setting can be modified by going Macintosh HD/System/Library/ExpansionSlotUtility ( can also be referred to PCI config utility) and modify the settings to have the slot that the raid controller card is in to run at 4 times instead of 1 time.
The following is the slot settings from top to bottom on our systems
Slot 4 - x4 - Atto Celerity FC - 42es
Slot 3 - x4 - AJA Kona 3 card
Slot 2 - x4 - G-SPEED eS raid controller card.
Slot 1 - x4 - NVIDIA GeForce 7300 GT - This can be different depending on your computer.