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
AnandTech Storage Bench 2011
Admittedly most of the benchmarks on the previous page really portray the Momentus XT in the best light possible. The workloads are light enough to mate well with the 8GB cache and none of them are really write intensive. Over time however you'll encounter more varied workloads, including those that are write intensive or those that only access data once or twice. In workloads that aren't perfectly tailored to the Momentus XT's cache, the honeymoon is over before it began. We'll start with our light storage bench:
Here overall performance is definitely higher than any of the 2.5" drive offerings, including last year's 500GB Momentus XT. However compared to the 3.5" Barracuda XT, the newer Momentus XT is tangibly slower over the course of our test. If you look at performance compared to the Intel SSD 510, there's simply no competition.
Our trace based Storage Bench suites were designed to really stress SSDs, thus being more write intensive than your typical client workload. Not being able to cache writes at this point, the Momentus XT is penalized (perhaps unfairly) in these benchmarks. The results are valid however - when it comes to writing or non-repetitive workloads, the Momentus XT will perform like a good 2.5" hard drive rather than in the realm of SSD performance.
Our Heavy Storage Bench workload is even more write intensive. Furthermore, having been recorded on a Windows 7 pre-SP1 install, we see some of the potential penalties from moving to a 4KB sector drive. Most writes are 4KB aligned in Windows 7, however pre-SP1 there were still some significant cases where alignment could be an issue. Here we see the 750GB/4KB Momentus XT actually fall behind the 500GB drive with 512B sectors because of this difference:
I included these results because if you formatted your drive with Windows 7 and later applied SP1 to the install, you may see this sort of performance regression when moving to a 4KB sector drive. The only way to avoid this is to reformat your drive using Windows 7 SP1 and install from a Windows 7 SP1 DVD/image. In place upgrades won't avoid the alignment issues that are exhibited here. For a greater understanding of why 4KB sectors are necessary and why alignment can be problematic on these drives, have a look at our coverage here.
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kyuu - Tuesday, December 13, 2011 - link
RAID0 does not "break" these drives. They work just fine, and you see the usual advantages of RAID0 and essentially will have a 1.5TB drive with 16GB of NAND cache.If you google, you will see plenty of reviews of the previous gen drive in RAID0.
Springfield45 - Tuesday, December 13, 2011 - link
Are these drives capable of supporting RAID arrays?If so, could an array of four of them in RAID 5 have an effective 24GB cache?
How would that effect performance?
kyuu - Tuesday, December 13, 2011 - link
1) Yes.2) Yes.
3) Google for reviews of the previous model in RAID0.
wharris1 - Tuesday, December 13, 2011 - link
I'm currently using the first XT in my laptop and have been very happy. Much snappier resumes and loading of chrome/email. Couldn't rationalize spending ~$4-500 for a decent sized SSD that might still get tight with all my pictures/media and the 500GB size for I believe around $150 was great. I do have a 240 GB OCZ vertex 3 in my desktop with a 2 GB WD black for storage but couldn't do that with my laptop, thus the XT was perfect. I also liked the prior poster's idea of using the new 750 GB XT as a desktop storage disk paired with a SSD, but at $245 seems a little expensive, but then, every HDD looks ridiculously expensive right now. Great review and I really like the overall price/GB/performance of these drives.RP94805 - Tuesday, December 18, 2012 - link
I agree with Current Owner...I actually have two of the 500 gig XTs - the first in my 6 year old duo-core notebook that I purchased when the XTs first came out (and yes that made a huge difference in keeping the computer usable for the last couple of years) and the second I just added to a brand new 14" i7 QM Notebook that I bought that had a regular 500 gig 5400 rpm drive as standard.
I bought the i7 and one of the few things I thought was limiting was the 5400 rpm drive - so since I needed the storage space and was happy with my first XT i looked to the 500 gig XT as it was only $50 on sale (timing was just right, at purchase there was mention of an additional $30 savings if purchased by 11.21.12.) This was by far the best $50 upgrade I could make to the system.
As to reliability, I have never encountered anything at all wrong about my first XT drive and it is still running strong - don't know if the very first batch were ok, then a bad batch, then "fixed" and that is what I bought now.
I definitely could not justify the additional $75-100 (on sale) for the additional size and slight increase in performance (and yes my i7 could make use of the Sata 6gb/sec speed of the newer model). Maybe in a year or two when prices drop the 750gig XT would then be a possible upgrade to my i7 notebook. But right now, I am a firm believer in the XTs over any 5400 rpm notebook drive and even to me the 7200 rpm notebook drives - the boot and shut down times are very SSD like (in my desktops I have the SSD + Large HDD setups) and for a business notebook where I frequently launch exactly the same applications (Excel, Access, PowerPoint, Chrome, etc) the application launch times are very fast.
beginner99 - Tuesday, December 13, 2011 - link
it costs 239. here in local currency.An intel 310 80 GB mSata costs 179.
A laptop usually already ships with a HDD and if it has an mSATA slot, buying the momentus xt makes no sense price and performance wise.
sheh - Tuesday, December 13, 2011 - link
What happens when the flash starts failing? Will the drive turn into a standard HDD, or become unusable? What's its life expectancy?Denithor - Tuesday, December 13, 2011 - link
It's SLC so with even a mediocre controller it's going to have a very long lifespan. Plus the fact that you aren't writing directly to the drive - it's writing only your most commonly used files and then reading them back multiple times - so as long as you're repetitive with your usage pattern there will be minimal writes and therefore wearing out shouldn't be an issue.kyuu - Tuesday, December 13, 2011 - link
The drive will essentially be a normal Momentus 2.5" 7200 RPM drive if the NAND ever fails for some reason. Everything in the cache is still on the hard drive.Keep in mind it's SLC NAND and you have a 5-year warranty, so, it's not really something to worry to much about.
sheh - Tuesday, December 13, 2011 - link
Did Seagate officially say anything on the matter?Yes, it's SLC (I tend to use drives more than 5 years), for reads only (for now), all the data remains also on the platters. But the drive will fail if the firmware wasn't coded to disable the caching mechanism when the flash starts failing. Doesn't seem likely it was ignored, but who knows.
It's not that I plan on getting one of these, but I'm curious nonetheless.