I wonder if JMB363 can support really full bandwidth of two SATA2 HDDs


SouthBridge of My motherboard is ICH8.

ICH8 doesn't support AHCI.

So, my motherboard has JMB363 storage controller.

JMB363 is a single chip, one-lane PCI Express to two-port SATA2 and one-port PATA Host Controller.

I connect four of my HDDs(two SATA2 and two IDE HDDs) to JMB363.

Bandwidth of one-lane PCI Express is 2.5Gbs. But, bandwidth of SATA2 is 3Gbs.

Theoretically, Full bandwidth of my four HDDs is 3+3+0.66+0.66 = 7.32 Gbs.

Surely, four HDDs hardly have an opportunity for Full speed operation simultaneously.

But, I think that one-lane PCI Express cannot cover the bandwidth of four Hdds.

Furthermore, can JMB363 handle I/O requests of four HDDs simultaneously?

I want to know about this.

Thank you.
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More about jmb363 support full bandwidth sata2 hdds
  1. Bandwidth of what? You're confusing the interface (SATA 3Gbps) with the speed of the drive. IF each drive can do no more than 125MB/s, then two disks on a PCIe x1 would be fast enough - since this offers 250MB/s for PCIe x1 gen1 and 500MB/s for PCIe x1 gen2.

    Besides i don't think you can use the PATA disks on the same RAID array. If you do, 4 devices on PCIe x1 is indeed a bottleneck. But likely you'll face other problems that cause you to not saturate the PCI-express interface.

    The real question is how efficient the RAID-drivers are; and i can tell you Windows software RAID does a better job. So if you don't need boot support; i'd recommend software RAID0 instead.
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