Seagate 2nd Generation Momentus XT (750GB) Hybrid HDD Review
by Anand Lal Shimpi on December 13, 2011 12:51 AM EST- Posted in
- Storage
- Seagate
- Momentus XT
- Hybrid Drive
- HDDs
- SSHDs
Power Consumption and Drive Behavior
Our power consumption tests are really worst case scenario for the Momentus XT since the cache is hardly given time to work here. In these tests the Momentus XT looks to be in-line with other, similar drives. In normal use however you may see even better behavior from the drive. If data is being requested out of the drive's NAND cache, the rest of the Momentus XT can actually spin down to save power. In practice I did notice the Momentus XT spinning up and down much more aggressively than a traditional hard drive. I know this was a problem with the original drive where it was a bit too aggressive in the power management department. My advice to Seagate would be to be more conservative here, particularly while only caching reads. The Momentus XT has the ability to deliver great performance, I'd leave the power savings for a version of the drive with a bigger cache and the ability to cache reads and writes. Otherwise I feel that the Momentus XT will do a lot of spinning up and spinning down for little gain.
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Anand Lal Shimpi - Tuesday, December 13, 2011 - link
According to Seagate the drive is still 9.5mm thick, just like the non-caching Momentus drive. I took a pair of calipers to the drive as well as a regular Momentus and both came up at just under 9.5mm (although my calipers aren't the super accurate variety, there could be some play in the numbers there). Do you have a reference to the 9.7mm figure?Still digging into FAST boot. If it works the way I think it works, it should be able to cache boot data from multiple OSes. Will find out for sure soon...
Take care,
Anand
Anand Lal Shimpi - Thursday, December 15, 2011 - link
Seagate provided a response to your second question:"The Momentus XT will learn multiple boot activities and retain the boot information for them in the boot partition. There should be no problem optimizing 2 or 3 different boot scenarios, but more than that may degrade the performance of the last first boot activity learned."
It's my understanding that it's not too hard to determine when a system is booting, the access pattern is fairly unique. The boot optimization simply looks for that pattern and has a small amount of NAND set aside for data that fits that pattern. Multiple OSes should trigger the optimization, but once you get beyond a certain threshold you do risk evicting useful data from the cache.
Take care,
Anand
b_flat - Tuesday, December 13, 2011 - link
No mention of the reliability?Head to the Seagate Forums or visit Amazon.com to see a list of continual problems with this drive
b_flat - Tuesday, December 13, 2011 - link
Amazon.comhttp://www.amazon.com/Seagate-Momentus-Solid-Hybri...
Seagate Forums
http://forums.seagate.com/t5/Momentus-XT-Momentus-...
Anand Lal Shimpi - Tuesday, December 13, 2011 - link
I mentioned the reliability issues in the video but I've added them to the conclusion as well. For what it's worth, both the old and the new Momentus XT have done well in my testbeds but as we've seen with SSDs in the past, that doesn't mean much.Take care,
Anand
Jonijc - Tuesday, December 13, 2011 - link
Hmmm....I only 5 star reviews on the new one: http://www.amazon.com/Seagate-Momentus-7200RPM-Hyb...
And 4 stars on the 500GB older one.
http://www.amazon.com/Seagate-Momentus-Solid-Hybri...
j
kmmatney - Tuesday, December 13, 2011 - link
I've had a 500GB XT drive for about a year - working great in a desktop computer. The $99 price seems like a steal now.applestooranges - Tuesday, December 13, 2011 - link
C'mon, the first Seagate Hybrid (released over a year ago?) was pretty much a joke, barely better than a normal 7200 rpm HDD. Anybody/everybody in the know could see this, but it somehow got praise from certain reviewers. Now, they release basically the same "non-innovative" and "non-effective" design, and it somehow gets a passing grade?50% better than nothing is still nothing.
I could spend half this much on an OCZ cache drive + a 1 TB HDD, and get twice (or 3x) the performance and more capacity.
these HDD guys just don't get it... how many years will it take them...
Anand Lal Shimpi - Tuesday, December 13, 2011 - link
I wouldn't say it's barely better than a normal 7200RPM hard drive, our numbers alone prove that's the case. As I mentioned in the conclusion however, my preference is still for an SSD + hard drive where possible. The Momentus XT really addresses the niche where you can only have one 2.5" drive and you need more capacity than an SSD can offer for whatever reason. In that case it does a decent enough job, but even then my preference would be for an internal SSD + external mass storage.Take care,
Anand
JNo - Tuesday, December 13, 2011 - link
Hi,don't often comment but really want to mention some possibilities that many seem to lack awareness of.
Firstly, I've read no mention, let alone review, of OCZ's Synapse Cache SSD on anandtech or of the NVELO dataplex software that drives it. It allows an entire SSD to cache an HDD but seems better than Intel SRT to me as faster and fewer limitations (no need for Z68 mobo, no SSD size limits). You can almost get a 3TB HDD to bench close to SSD speeds. I think they're looking to release the software one day too so you won't even need the proprietary OCZ SSD. Reviews:
http://www.storagereview.com/ocz_synapse_cache_ssd...
http://www.storagereview.com/nvelo_drives_storage_...
Secondly, you can get cheap optical drive bay HDD adaptor for laptops nowadays (ebay) so you can slot a second SSD/HDD where the optical was. This allows classic boot SSD + data HDD combo in laptops without mSATA. In fact it's a reason for me to look for lappies *with* an optical drive even though I'd otherwise prefer not to have one. Obviously this solution won't work for ultrabooks etc but still much more preferable to the Seagate Momentus for me.