Seagate Momentus XT Hybrid Drives

[Geeba]

Morning all,

Thought I would share my experience with the Seagate Momentus XT Hybrid drives.

Anyone thats not heard of them, they are traditional mechanical HDD's with a 4GB NAND flash cache and some clever learning software that is supposed to give SSD like performance with the capacity of an ordinary HDD.

http://www.seagate.com/gb/en/internal-h ... rid-drive/

As they are pretty reasonably priced at £59 for 500Gb I thought it might add a bit of welcome zip to the Xbox - initial test were good, the SATA adapter performed well - HD Tune Pro gave some really good figures through the adapter, so if the Xbox IDE interface is as it rumored to be all these years and indeed capable of ATA 100/133 then this baby would easily have the I/O side of things flat out! just as I like them!

The drive built fine, locked fine, the M/S Dash was fine, EvoX was fine... it was all looking great, very VERY quiet, and very cool..... until, you fully power off the xbox! then nothing, the XT Hybrid just ticks like a failing drive.

I thought this might of been a problem to do with the fact that my mate had dropped the drive (twice) getting it to me, but that was RMA'd and the new drive that replaced it failed at the exact same point, so my findings would point at these drives as being incompatible with the humble xbox.

I can only assume its something to do with the NAND cache and built in software

G.

[professor_jonny]

it probally is that the xbox does not commit the cache to drive bitmap or nand before the shutdown, but it could be that the drive floods the ide interface as it is too quick.

to find out you could power the hdd via an external source and connect up a ttl logic interface to the hdd then fire up hyperterminal on your pc and check for a flush when you press the power button and look for error's while copying stuff to and fro.

i did this my self to try figure out why you cant have a sata drive and no dvd drive fails to boot but i could not find any error codes relating to why.

checksum error between nand flash and drive bitmap is a likely cause and the drive will be searching the drive bitmap over and over the same datablock thinking there is an error.

[Geeba]

- not sure I'm going to do much more testing on the Hybrid drives... its already completely killed one drive.... wont unlock, PC fails to boot when its connected.

Its odd thou as SSD's which are faster again work ok...

[professor_jonny]

just a normal locked drive will cause my pc to not boot up. i have to connect my xbox drives after boot or it hangs the computer.

[2 Bunny]

Do these make a noticeable difference in performance on a computer versus a standard hard drive to any of you guys?

[professor_jonny]

yip they make a difference also work well in laptop save battery

[Geeba]

Go SSD IMO..... it doesn't feel that quick in my games rig... the older 10K Velociraptor feels alot faster.. they seem ok in reviews etc but I wasnt blown away like I was when I first went to SSD! .. not sure on battery saving thou as its technically a conventional HDD with a large/fast cache

[professor_jonny]

Go SSD IMO..... it doesn't feel that quick in my games rig... the older 10K Velociraptor feels alot faster.. they seem ok in reviews etc but I wasnt blown away like I was when I first went to SSD! .. not sure on battery saving thou as its technically a conventional HDD with a large/fast cache

it's not really the same as a write through cache method is updated to disk at the same time the cache is modified and the write back method drives comit to disk on cache change tracked by dirty bitmap on a typical ram based cache.

the actual hardware cache on a normal disk is mostly used for pre fetching and does bugger all in the write department.

On a hybrid there is not typical tracking of cache bitmap or need for write through as the drive retains it's cache as it is permanant storage it iss comitted to disk on cache filling up or some math calc based of prefetching.

drive writes are minimised reducing the run count and time of the spindle they save power but sure the ssd is the way to go but they are a good tie of between the expence of a ssd.

the 10k drives often have very fast seek times that make them feel snappy but they are not far off par with ssd's price wise.