How many SATA devices can M55 support?

[gerchikov]

ThinkCentre M55 (8811-WDL) with the latest 2MKT49AUS BIOS runs fine when four SATA devices are connected (3 HDDs + DVD_ROM) but hangs at boot time when the fifth SATA HDD is connected.

When connected, all five devices are recognized correctly and show up in BIOS System Summary screen. All HDDs also show up correctly in BIOS RAID setup (RAID is enabled). POST, RAID and AMT startup screens all progress normally and complete successfully, but the system hangs right after it, when Windows logo (or Windows F8 menu) would appear otherwise. By "hangs" I mean that boot stops and the system does not respond to keyboard -- I waited for 15 minutes to make sure. Forced power-down (by pressing power button for ~5 sec) is the only way out.

If I disconnect *any* one of the five SATA devices, the system boots successfully and all four remaining devices are visible from OS and work correctly. If I hot-plug the fifth device while the system is up and running, the device is recognized by OS, installs and works correctly. So I can't blame the devices. Also, I can't boot from bootable USB stick or CD-ROM either, so it's probably not the OS. Seems like a BIOS problem.

Help, please!

[lead_org Microsoft MVP Contributor]

i have tried 4 sata devices in the m55 tower and that works correctly. If the fifth sata device is not working, then just stick with 4 sata devices. 

[gerchikov]

I am sorry, but this is not helpful. I know (and have mentioned) that four SATA devices work in M55. My question was how/if it's possible to make the fifth one work, *not* whether I should stick with four. There must be a reason for the five SATA connectors on M55 MB.