i have my own take on this, (have also spoken to some local "techs"), but am still not sure what exactly it's supposed to mean. calling wd tomorrow. i'm talking about the jumper setting note. haven't seen that before on a sata drive. what do you make of it ? i've read the page @ http://wdc.com/en/products/advancedformat/ and whilst i fully understand what is written, it's not clear what the performance gain is supposed to be or what the hell it does. because: i have it running under xp sp3. originally i did not see that note and simply installed it without a jumper (let alone use their software) just like all my previous sata drives. the bios saw it and the system did too. as far as i was concerned it worked. one of the 1st things i do when i get a new hdd is use hdtune to bench it. i did, and the results were what i'd expect. (see 2nd pic below) i also filled the hdd to nearly capacity (minus around 50gb) all is/was good. the data is there and seems ok. anyway, out of curiosity i shut down and jumpered it (7-8) upon boot into o/s the drive was erased (but that's cool as everything that i want to put on it is on my pc right now (on a 2tb baby), and on 8gb dl dvd discs as a 3rd backup - yeah i'm paranoid, so no drama at all.) and i had to use computer management to initialize it as a basic drive. in mere seconds i had it as a fresh 1.5tb drive again. ok let's bench it to see what this boost might be. after running the bench it was identical. rebooted, reformated tested again.. same performance. so best i can tell i don't see the point of jumpering it like they say, especially because......===> the reason for this drive is that in the next few days i'm gonna fill it up with "important" data and keep it offsite (parent's place) as one of my "secure" backups. so whilst i'm using xp today, and hopefully i'll never have to use this drive to "restore" the data, but if i do i assume by then i'll be using win7 or better and where does that leave me ? could that in itself cause problems ? since for vista/win7 it should be jumperless, does that mean if i use it jumpered in my current xp setup to backup to it but the restoring will take place in the future on win7 that could be degraded or cause data corruption issues or what ? (calling wd on their 1-800 number tomorrow, i must hear what they say about it.) in conclusion i have now had this drive under xp with and without the jumper, benched it under both setups and see no difference at all. i can copy to/from it, have filled it up, erased from it, run chkdsk /f on it, and all is/was/seems ok. is the jumpering a con of sorts or what ?? performance looks ok - anyone disputing this ?