I've recently bought a MSI 790FX-GD70 AM3 board with which to build myself a new system. I've also got 2x Corsair Extreme Series X64 64GB SSDs which I want to put in RAID 0 as my boot drive. The Mobo has 8 SATA connectors - 2 controlled by a JMicron JMB322 controller which is where I pluged in the SSDs. I built the system up and all went well until I ran HD Tach on the drive and found the max throughput was about 130MB/s. This was a bit disappointing as a single drive is supposed to get about 210 MB/s. So I did a bit of experimenting. Undid the RAID and installed the OS on a single drive, booted and ran HD Tach - this time the result was about 115 MB/s. Next I Plugged the SATA lead into one of the ports controlled by the SB750 and the result was about 200 MB/s. This lead me to believe the JMB322 is only using SATA 1.5 even though www.jmicron.com/JMB322.html clearly states it's SATAII compatable. I can find nothing in the BIOS to switch over to using SATAII. Has anyone got any ideas as I'm a bit stumped now. I'd really rather use the RAID on this controller as no drivers are needed and the machine boots about 10-15 secs faster.
From the manual on MSI's 790FX-GD70 download page. It looks as if the JMB322 controller is tied into the main On-Chip ATA Device. As the manual states, its a Drive Booster (HW RAID) (for JMB322, SATA7~8)
It sounds as if the setting on the On-Chip ATA Device you have here is set to RAID or IDE. This might be confusing the JMB322 controller?
First, make sure all firmware is updated. Including the SSDs.
Go into the bios and look for: On-Chip ATA Devices
Press <Enter> to enter the sub-menu
Look for: RAID Mode
Take note of the options: This item allows you to configure SATA mode. Setting options: [RAID],[AHCI] or
Set to AHCI.
Reboot and test a single drive. If you get the performance that you expect then give raid 0 a shot.
This setting is independent of your JMB322 controller. I am pretty sure this also informs the JMB322 controller how to interpret the hard drive controller(s).
It could be also that the JMB322 controller needs a firmware update that is still in development? Integrated hardware is very dependent on the MB capabilities and bios firmware. So this is where I would begin to solve this problem.
I remember reading a review that the jmb322 controller doesn't have all the pci express lanes made available to it whereas the 750 chip does on an amd board. Also it is sharing some resource which further limits it's output.
It's still nice to have though.