Seagate Momentus XT ST95005620AS 500GB 7200 RPM 32MB Cache 2.5" SATA 3.0Gb/s with NCQ Solid State Hybrid Drive -Bare Drive

 

$99.99 after promo EMCZNPY49 (expires 1/5/2011)

 

That's the price I was waiting for, I'm ordering one.  Should work well for my digital DJ laptop.  If you aren't familiar with the drive, here's a great discussion of it:

 

Comparing the Seagate Momentus XT Hybrid drive, SSDs, and HDDs

I love this drive. I put it in my laptop and instantly felt a performance boost.

It's in the middle between a regular 7200RPM drive and an SSD.

I was planning on buying one to put as a cache drive - since most SSD are a bit too small or too expensive..is this a good idea?

I was planning on buying one to put as a cache drive - since most SSD are a bit too small or too expensive..is this a good idea?

 

IMO, I don't think it's worth the premium in this context.  I have this hybrid as my system drive in a workstation and it helps, but it "learns" your usage patterns over time with reboots... I'm not 100% sure what the algorithm is, but it seems the flash cache is not a basic MRU.  Writes to the disk never hit the flash memory, nor is it large enough to make a significant difference if you are regularly dealing with large media (4+ GB sized chunks). 

 

So I'd think what'd happen with the drive (at least in my most common use case):

1. An 8 GB video file gets written to the XT acting as unRAID cache.  No performance benefit over a standard HDD since data is going directly to spindled disk.

2. unRAID runs its normal cache->array transfer overnight.  No performance benefit, because this data is being read for the first time, and it's going away anyway from the cache drive once it's deleted.

 

If you write/read lots of small files regularly to your unRAID cache drive, then there may be a benefit.

 

If it's a small, low power drive you're looking for, you can always just buy a standard 2.5" HDD.

 

yup this drive is great. I have one in my Mac Book Pro. As Nyago123 noted, it learns your usage over time with reboots in between. I doubt one will be rebooting their unRAID server that often so I don't see a benefit in an unRAID system

 

J

As mentioned by other posts, this is not the best drive to use for unRAID unless your cache drive houses other permanent applications.

In my case I have hidden folders where I store, read & write files which stay on the cache all the time.

 

For normal unraid Cache usage, the cost is better spent on a drive with the equivalent size of your parity drive.

Then in an absolute worst case scenario, you can give up the cache drive and restore the failed drive with the cache drive while you have a replacement being delivered.

Recently put one of these in my macbook pro and I must say I'm happy with it,  very noticeable difference in boot times.

Back down to the $99 price:

 

Seagate Momentus XT ST95005620AS 500GB 7200 RPM 32MB Cache 2.5" SATA 3.0Gb/s with NCQ Solid State Hybrid Drive -Bare Drive

 

$5 off using promo code EMCKHKJ28, ends 2/7

 

I'm quite happy with the drive that I bought when it first went on sale.