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My current setup runs on top of 2x Western Digital 2500KS drives on Raid-1, using the motherboard's 780G raid controller, on WinXP. Everything is fine, but the drives are a bit noisy.

I am considering buying 2x WD6400AARS disks which are the 640GB slower 'green' drives, but also feature the Advanced Formatting 4KB sectors. This means that for WinXP the partition will have to be aligned to work properly, else there is a performance penalty.

There are 2 questions here: The Green drives from WD are all slower and are (according to WD) susceptible to drop-out's from the controller. Has anyone any experience in this matter? Is there a possibility the controller will drop a drive? If so, can i do anything about it?

Secondly, western digital gives a utility to perform the alignment on the partition. The thing is, will the utility see the drives in question as the operating system only sees 1 logical disk?

I will be making the transition using a cloning tool (most probably norton ghost) unless i don't find a solution or a clear answer, in which case i'll just buy a win 7 license and make a clean install...

thx in advance

EDIT: a link to the reference as requested http://community.wdc.com/t5/Other-Internal-Drives/1-TB-WD10EARS-desynch-issues-in-RAID/td-p/11559;jsessionid=CCE4987D779323EBE952FFD7E82679F6

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If the manufacturer themselves suggests that the drives are likely to be problematical for RAID arrays (could you link to your reference for that information please, it could be useful to others) then do not use them in a RAID array.

I suspect that the problem will be the green features making the drive seem to pause when requests are made after it has been idle for a short while (because it is presumably being very aggressive about powering down when idle). RAID controllers may see this delay as a problem and drop the drive from the array. As it isn't actually a problem you should just be able to tell the RAID controller to mark the drive as OK and resync, but if the other drive drops the same way before the resync is complete you may end up with a completely corrupt array, with no one drive holding a completely correct copy of the data - and the resync could take some time (unless your controller uses write-intent-bitmaps or similar, the resync will involve copying the whole 640Gb from one drive to the other).

There have been problems like this with other ranges of drives in the past (certain revisions of Seagate's 1Tb range are some that I remember people having trouble with though I think their issues were resolved by firmware update) usually caused by the drives responding unusually slowly when they encounter certain recoverable error conditions.

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good advice. i have a new-ish pair of 1TB green drives (Seagates, IIRC) that i considered putting into a RAID config; this makes me even more glad i didn't. –  quack quixote Apr 15 '10 at 13:05

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