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Hardware RAID problem

Last response: in Motherboards
October 16, 2009 8:03:14 AM

Hi All,

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 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.


More about : hardware raid problem

October 16, 2009 12:24:52 PM

Well the JMicron controller chips really are lackluster in their performance in everything as a whole. The JMicron chips are compatable with sataII but they will only operate @ SATA I specs. There is nowhere in the bios to "enable" sataII on the JMicron controller. A better faster solution IS the SB750 chipset if you want to be faster. You will have to install the drivers for it during the OS load as there is no way around it. (For raid 0) Boot speed is not the true measure of a system.
October 16, 2009 3:56:52 PM

Thanks for the quick reply!
After reading around a bit, it does seem that the JMicron chip is a bit pants! I guess I'll put the RAID onto the SB750 and 'suffer' the extra boot time :) 

10-15 secs doesn't sound much until you put it in the context of: BIOS load = 5sec + OS load = 10sec. Then it's nearly doubling the boot time!
October 19, 2009 2:59:39 AM

The JMicron JMB322 just can't have any decent throughput, simply because it's on a Pci-E single lane, which limits to 250MB/s theoretically and far less in fact.

Nowadays, disks (Hdd and Ssd) have throughputs exceeding most of the entry points to the chipset (unless you have a Pci-E 4x slot), so the only good place to connect a Raid-0 is the south bridge.

On a single disk, my Jmb363 isn't that bad... But its Bios subroutine adds extra 4s to the boot time in Ahci or Raid mode, so it's shut off now.