SSDs vs. Seagate SSHD (Momentus XT) - a discussion

[Ledgem]

About one and a half years ago I upgraded my MacBook Pro's stock 200 GB 5400 RPM hard drive to a Seagate Momentus XT 500 GB, 7200 RPM with 4 GB flash memory to function as the SSD portion, SATA II. The difference in speed was incredible, although I wasn't sure how much of the difference was due to the bump from 5400 RPM to 7200 RPM (which already makes a big difference) and how much was attributable to the hybrid SSD portion. I could see that using certain programs repeatedly, resulting in the drive "learning" and storing their data regions to the SSD, resulted in vastly improved performance - performance that then tumbled when they weren't used for a long time (such as switching between dominant web browsers for months at a time).

But I wanted more. There are videos of multiple programs opening instantly with a SSD, and there are plenty of benchmarks to show that SSDs are still faster than Seagate's hybrid drive solution. Some people claimed that SSDs still blew away the Momentus XT. About a week ago I came across a good sale on a 500 GB version of Samsung's 840 SSD line, and bought it. This is Samsung's consumer-grade SSD using TLC flash memory, which means reduced endurance compared with MLC (and of course SLC) and somewhat poorer performance. I've now been using the drive for about four days, and wanted to share some observations. I'd also be interested to hear others' experiences and thoughts. (Note: the Seagate Momentus XT line has now been rebranded as "Solid State Hard Drive," or SSHD. I'll refer to it as "Momentus XT" or "XT" throughout this post.)

It's one of the worst metrics but everyone always remarks on it: boot speed. Even though I only reboot once every week or three, this has been dramatically improved. Even after rebooting a few times so that the Momentus XT moved the relevant data to the SSD for faster performance my bootup time was still at least ten seconds. With the 840, the "loading wheel" on the boot screen displays for what seems like less than a second before disappearing. I haven't clocked it, but bootup time is less than ten seconds for certain. Logging into my account - which has a bunch of background programs that load at startup - is also much faster than the XT.

But this is where I find myself slightly disappointed, although I'll admit that my expectations might have been unrealistic. I've seen videos where people open multiple programs at once and the windows snap open before the programs have completed a single bounce on the OS X dock. While the 840 is faster than the XT (and there's no need to wait for the drive to "learn" your activities), it's not noticeably that much faster. My big test for this is loading Apple Mail, which has tens of thousands of messages dating back for years in its database. The Momentus XT would bring up the Mail window in a single bounce, but then would delay for two or four seconds while the messages were loaded. The Mail dock icon bounces two to three times with the 840, but when it's done bouncing the program is fully ready to go: all of the messages have been loaded. While I haven't used a watch to time it, I feel that the 840 is either barely faster or about the same as the XT when it comes to load times there.

This isn't to say that the drives are completely equal. Certain websites cause very brief pauses as a plugin was initialized; while the Momentus XT cut down on those pauses, the 840 has seemingly completely eliminated them. (Also, if you switched browsers then the pauses would become very apparent with the XT - at least, until a few uses, after which the drive would store the browser parts on the SSD.) Spotlight searching is near-instant with the 840, while the XT would still take a second or two to fully compile all results. Thumbnail loading in the Finder is faster with the 840, but not massively so - and it's not instant.

If you look over benchmarks, the 840 is far from being the worst performer. In benchmarks I've seen (specifically HotHardware's review) it fares very well in read performance tests, only lagging in write performance. For casual home use the read performance matters more, so this isn't a big issue.

Ultimately, what I'm noticing may be more noteworthy to the Momentus XT instead of critical of the Samsung 840. Perhaps it isn't that the Samsung 840 is poor or underperforming, but that the Momentus XT really is just that good. That would be all the more impressive considering that the 500 GB variant that I have is supposedly noticeably slower than the 750 GB variant that was released a bit after it (which doubles the on-board SSD capacity from 4 GB to 8 GB and supports SATA III). The Momentus XT certainly felt like a huge improvement over the 5400 RPM drive that came with my Macbook Pro, but perhaps that was close to as good as it gets for average, casual use, and the Samsung 840 can't offer much over that.

I have moved my Momentus XT over to my wife's computer. Originally I was thinking about finding a smaller-capacity SSD on sale and then replacing the Momentus XT yet again, but after these findings I don't feel the need to. SSDs will inevitably become faster and cheaper with time, and when I need to upgrade or replace my Samsung 840 I will carefully evaluate the performance of SSDs against the hybrid HDD/SSD offerings. I don't regret the purchase and still appreciate the little speed boosts, but at this point I would buy another Momentus XT over a SSD if I were performing an upgrade to a system. But who knows? After I spend more time with the 840 and get used to it I'll switch over to my wife's computer to see if it feels noticeably slower. Speed increases aren't appreciated quite as much as poor performance, after all!

For reference, these observations were all made on a late 2011 Macbook Pro, 2.2 GHz i7 with 16 GB of RAM running at 1600 MHz. I have external drives that occasionally slow down operating system and program operations. The Samsung 840 is running the latest firmware version (DXT07B0Q), has had a few optimizations made with Chameleon SSD Optimizer (TRIM enabled, NOATime disabled, local backups disabled, sleep mode A), and is filled roughly halfway to capacity (252 GB used, 247 GB free). I have used the Blackmagic Disk Speed Test to verify that my drive is operating similarly to others (write speed seems to go up to 330 MB/s, read speeds to 505 MB/s), but of course, these are raw speeds that don't indicate anything about the random read performance that impacted my observations.

TL;DR buying advice: For regular home use (random read/write activities predominate) there doesn't seem to be a major difference between the Seagate SSHD line and the Samsung 840. If your only needs are speed and storage space, either go with a SSHD drive (7200 RPM variant; I don't know how the new 5400 RPM drives fare) or pony up and get a higher-end SSD.

[Random32]

Don't worry. You'll eventually get used to the SSD and the extra few seconds that stuff takes to open on an HDD/SSD hybrid or HDD based machine will be painful.

Source: Experience.

As for upgrades and being cost conscious, I would also take a look at a few other options if you don't want to spend half of your budget when buying a new computer on solid state storage:
-Obvious, if you are on a desktop, just get a small SSD boot drive with a big HDD for storing stuff
-Some laptops support mSATA SSD's, which means you can do the same as above
-Or you can use the mSATA SSD as a cache. It would work like the Momentus XT, but you could have a larger SSD cache that makes more things snappier.

Also, SSDs also have advantages beyond speed. They are very durable compared to HDDs and lower in power consumption.

[Ledgem]

Originally Posted by Random32

Also, SSDs also have advantages beyond speed. They are very durable compared to HDDs and lower in power consumption.

This is true. I haven't encountered a laptop hard drive that would qualify as "loud" but SSDs also offer the benefit of being completely silent.

I figure that my wants are the same as the average consumer, though: storage space and drive speed. You're paying a premium for storage space at the moment, and it's done with the expectation (and hope) of receiving a huge speed boost. I'm just not convinced that the cost over the hybrid "SSHD" is justified by the comparatively small speed boost. It's also worth noting that the Seagate 750 GB variant of the Momentus XT (with doubled SSD capacity) is even faster than the 500 GB variant that I was using, according to user reviews. Now all of Seagate's newer SSHDs are using 8 GB on the SSD side. That should theoretically narrow the gap between the SSHD line and the Samsung 840 even further.

I'm sure there would still be noticeable differences (the raw read/write speeds will never be equaled by the SSHD), but for average use I'm not convinced. The Samsung 840 is fast, but the SSHDs kept up surprisingly well - and they were only about a third of the cost.

I'm bearing in mind that the 840 line is very much consumer-focused and that it's using TLC, instead of the more standard MLC. Despite what the benchmarks say, I'm wondering if other SSDs really are much faster in normal usage.

[sa547]

Thanks for the evaluation. As a Seagate user for more than a decade, makes me think about the interesting implications such a hybrid design could bring, but even then looks like I'll have to wait for the price drop (right now a Momentus XT 750gb costs a little more than a 2TB traditional drive, but I have to remind myself that several years ago 320gb drives were much more expensive).

[Random32]

Originally Posted by Ledgem

I'm just not convinced that the cost over the hybrid "SSHD" is justified by the comparatively small speed boost.

It's a lot of small speed boosts. Right now probably only some OS stuff and your most frequently accessed programs and files are on the SSD side. 8GB isn't much. As you mention, if you go for all SSD, everything will be that fast.

Yes that can translate to "stuff I use once in a blue moon will open quicker," but it can also translate to things that really take forever to load (games, etc) being a lot faster. Those things are much faster on bigger cache/all SSD since they aren't cached by the smaller cache since they are too big to fit.

I'm bearing in mind that the 840 line is very much consumer-focused and that it's using TLC, instead of the more standard MLC. Despite what the benchmarks say, I'm wondering if other SSDs really are much faster in normal usage.

Depends on what you call normal usage. Load times for small programs aren't going to get any more instant. Games will load faster though, and really disk restricted stuff like working with raw video will go much faster (provided the rest of your system can keep up).

[creb]

I assume most desktop users with SSD also have a normal HD or two as well. It's not like it's an either/or situation.

SSD for the OS, and the games you frequently play, HD for everything else.

I just swap games from one to the other as needed, rather than uninstall/re-install.

OS boot times and game load times are the types of things you'll want to tear your eyes out when dealing with them on a non-ssd drive, once you're used to the speed improvements. Windows 8, on my desktop, literally spends longer at the Bios screen than it does on actually loading the OS, though the whole process-from a cold-boot takes maybe five seconds. Edit: Ok, I just timed it. Starting from when the bios screen starts, 3.89 seconds. I actually think it takes longer for the power button to flip the switch and get the motherboard juiced.

Some games are more affected by load times than others, but most games that have load times do see a marked improvement. SWTOR on a normal HD could take 45+ seconds to load some of their bigger planets, but on a SSD takes 6-10 s. Huge improvement there, but WoW had little difference in load times, so you're not going to see improvements in everything. Those are probably the two extremes that I can think of, with most games falling somewhere inbetween.

Haven't met any normal programs that take long enough to load where being on a SSD matters all that much, so non-gamers probably have less use for using one. About the only program I use with any regular basis that did take more than 5 seconds to load on a normal 7200 rpm drive would be Photoshop, and there's definitely speedup there. The various office 13 applications open almost instantly (.5-1 second load times).

With the many factors contributing to performance, hard drive is obviously not the only factor, but all else being equal, I do think even a 128 GB SSD is worth the money (for a desktop at least; for laptops, as long as you're willing to use an external hard drive for storage purposes, I think an SSD is worth it there as well).

Oh, but I don't use OS X. If that makes any difference.

While I haven't used a "hybrid" drive, it's largely due to not seeing any logical point to doing so. I have a very difficult time believing you really get similar performance between one and an SSD. /shrug

[Ledgem]

Originally Posted by creb

While I haven't used a "hybrid" drive, it's largely due to not seeing any logical point to doing so. I have a very difficult time believing you really get similar performance between one and an SSD. /shrug

The results vary depending on which benchmark you read, with some showing that it's very close and others showing that there's a big difference. A lot of users talk about a hybrid being only halfway to a SSD, implying that the SSD should still blow away the hybrid drives. That's why I was so surprised when I swapped out my 500 GB Momentus XT with a 500 GB Samsung 840 (which should be faster than the 250 GB and 128 GB versions of the 840) and didn't feel that there was a huge difference.

Make no mistake, there is a difference. And in the cases that random32 is talking about (games and level load times) I'd imagine that there's a big difference to be had. Being an OS X user, you can probably tell that gaming isn't a huge thing for me (although I played The Witcher with the Momentus XT and noted that level load times would receive some acceleration as I played, although I have not played the game on the 840 to see how much of a difference there is).

My interest is more in terms of raw productivity, though, opening and closing programs and doing fairly basic tasks. Using a certain set of programs repeatedly is an area where the hybrid drives excel. Based on this experience, I can say with certainty (and some disappointment) that the hybrid drives do indeed approach the performance of a SSD.

I will note that OS X does seem to have a bad habit of accessing external drives even if seemingly nothing about the task at hand requires them. While that handicap would apply to both the Momentus XT and the 840, it may be holding the 840 back even further. When I have a chance I'll disconnect all externals and see if the 840 feels any faster, unhindered by the external HDDs.

[synaesthetic]

Easy decision is easy, even for a laptop.

Internal SSD (128-256GB) and external USB3/Thunderbolt HDD for media and such.

For desktops it's a no-brainer. The NAND-cache hybrid drives are okay but they're not all that much faster than a regular 7200RPM drive.

[Ledgem]

Originally Posted by synaesthetic

Easy decision is easy, even for a laptop.

Internal SSD (128-256GB) and external USB3/Thunderbolt HDD for media and such.

For desktops it's a no-brainer. The NAND-cache hybrid drives are okay but they're not all that much faster than a regular 7200RPM drive.

It's more convenient (and cheaper) to simply get a higher-capacity hybrid drive. And if what I'm experiencing is normal and common, there's not much performance benefit in going with a SSD over a hybrid drive.

[synaesthetic]

I guess not, but I'd never trade my SSD for a spinny platter. Usable OS from a cold shutdown in under 10 seconds.

[Ledgem]

Originally Posted by synaesthetic

I guess not, but I'd never trade my SSD for a spinny platter. Usable OS from a cold shutdown in under 10 seconds.

True, but how often do you do a full shutdown? Some people shutdown regularly, and a SSD offers a huge benefit in those cases. It seems like most people simply suspend their systems, though, and even reboots are fairly rare. As a result there isn't much of a saving there, either.

[synaesthetic]

Originally Posted by Ledgem

True, but how often do you do a full shutdown? Some people shutdown regularly, and a SSD offers a huge benefit in those cases. It seems like most people simply suspend their systems, though, and even reboots are fairly rare. As a result there isn't much of a saving there, either.

For a desktop it's actually not a big benefit since I just let it sleep, but it's a huge boon on my laptop, which I shut down completely all the time. I have a smaller SSD in the laptop (an oldie but a goodie--Thinkpad X200) and it boots from a cold shutdown in around 12 seconds on the 80GB Intel SSD I put in it.

[Irenicus]

I recall the early Momentus having serious reliability problems.

Have they improved since then?

One thing you trade away buying a hybrid is that they are just as vulnerable to hard drive roulette of old, compared to buying a (reliable, good firmware) SSD.

[Ledgem]

Originally Posted by Irenicus

I recall the early Momentus having serious reliability problems.

Have they improved since then?

I don't know. All I can say offer is this: the observation that I haven't had issues with mine, and the reasoning that Seagate is now shifting away from traditional HDDs and further expanding their SSHD lineup. I don't imagine they would do that if the SSHD lineup had a higher failure rate than standard HDDs.

Originally Posted by Irenicus

One thing you trade away buying a hybrid is that they are just as vulnerable to hard drive roulette of old, compared to buying a (reliable, good firmware) SSD.

I've come across a number of horror stories about SSDs failing, even from "reliable" manufacturers, and seemingly for no good reason. Going based purely off of anecdotal stories, I don't know that SSDs have a lower failure rate than HDDs at this point in time. It's a pity that the industry doesn't make this sort of data readily available, although it's understandable why they don't.

[demonix]

Originally Posted by Ledgem

It's more convenient (and cheaper) to simply get a higher-capacity hybrid drive. And if what I'm experiencing is normal and common, there's not much performance benefit in going with a SSD over a hybrid drive.

That would be true on less access heavy programs, but once you get to top end games and the like the performance advantages of a SSD become clearer so I thought that I should post this comparison test video between an SSD, the momentus XT and two standard hard drives (one 10K RPM and one 7200 RPM).

[Ledgem]

Originally Posted by demonix

That would be true on less access heavy programs, but once you get to top end games and the like the performance advantages of a SSD become clearer so I thought that I should post this comparison test video between an SSD, the momentus XT and two standard hard drives (one 10K RPM and one 7200 RPM).

I could believe that the SSD advantage would be clearer for games. That was a neat video, but I didn't like two things about it. All tasks were back to back, meaning that as certain drives fell behind it became difficult to make comparisons with the speed differences. Second, running through a number of varied tasks (for the first time? I don't remember if they remarked on that in the video) doesn't allow the Momentus XT's SSD advantages to come through.

At this point I think it's fair to say that I'm not a gamer. My gaming days are over, at least temporarily. For normal day-to-day use (email, spreadsheets, web browsing, video conferencing, minor photo editing) the benefits of the SSD (at least, the Samsung 840) aren't all that noticeable over the Momentus XT.

[0utf0xZer0]

Unless I'm reading the results panel wrong, the Momentus XT actually beats the SSD on the Crysis Warhead test, which more or less confirms what I've heard that most games are far from disk limited.

I'd be interested in knowing how an SSD and a Momentus XT compare for responsiveness when browsing a large lightroom catalog - I suppose it could cache the catalog and previews while not caching the original files? Creating the previews themselves would take longer of course, but when one considers how fast a large number of photos store in RAW will burn through free space it starts to look like a better option.

(Personally, my biggest complaint with mechanical storage and responsiveness is how long it takes them to spin up after being idle - I run into this one a lot as I keep many, many files on an external drive due to switching between two desktops all the time.)

[Irenicus]

Originally Posted by Ledgem

I've come across a number of horror stories about SSDs failing, even from "reliable" manufacturers, and seemingly for no good reason. Going based purely off of anecdotal stories, I don't know that SSDs have a lower failure rate than HDDs at this point in time. It's a pity that the industry doesn't make this sort of data readily available, although it's understandable why they don't.

SSDs are moving generations rather rapidly. By now it's considerably more reliable than just a year ago, much less two.

The horror stories survive a few generations each.

Of course, if the current Momentus XT is more reliable than its predecessors, then that's good. Competition, useful transitional technology, and price...

Originally Posted by 0utf0xZer0

Unless I'm reading the results panel wrong, the Momentus XT actually beats the SSD on the Crysis Warhead test, which more or less confirms what I've heard that most games are far from disk limited.

The test is done with an SSD that's basically a third in capability of real current generation SSDs in the market. Or, heck, half or less of last generation's SSDs.

It's not close to fair to SSDs of today. [2010 was a very young time for SSDs. Some of them were slower at certain workloads than hard drives! Just about none of any half-decent SSDs on the market will face that problem today.]

It is, however, a demonstration of the potential of the hybrid form above traditional HDDs, even 10K RPM ones, until SSD's long term reliability is better proven and the storage cost per GB becomes more affordable for the mainstream (one of the good things Apple did is pushing SSDs hard such that the technology is rapidly gaining ground, market share, and efficiency of scale).

[creb]

Originally Posted by Ledgem

At this point I think it's fair to say that I'm not a gamer. My gaming days are over, at least temporarily. For normal day-to-day use (email, spreadsheets, web browsing, video conferencing, minor photo editing) the benefits of the SSD (at least, the Samsung 840) aren't all that noticeable over the Momentus XT.

Oh, I absolutely agree there's little point in an SSD beyond boot times to load into your OS of choice, for general use computers.

And, if the future for PC applications are "Apps", rather than mammoth sized desktop applications, I imagine that'll remain true for the conceivable future.

However, any PC gamer who hasn't installed an SSD alongside their HD, is doing themselves a huge disservice.

[0utf0xZer0]

Originally Posted by Irenicus

The test is done with an SSD that's basically a third in capability of real current generation SSDs in the market. Or, heck, half or less of last generation's SSDs.

It's not close to fair to SSDs of today. [2010 was a very young time for SSDs. Some of them were slower at certain workloads than hard drives! Just about none of any half-decent SSDs on the market will face that problem today.]

It is, however, a demonstration of the potential of the hybrid form above traditional HDDs, even 10K RPM ones, until SSD's long term reliability is better proven and the storage cost per GB becomes more affordable for the mainstream (one of the good things Apple did is pushing SSDs hard such that the technology is rapidly gaining ground, market share, and efficiency of scale).

The main thing I remember regarding SSDs and gaming a few years back was that your typical scenario was along the lines of "cut load times from 43 to 36 seconds" - hardly refelective of the actual difference in hardware performance and an indication to me that the disk wasn't the only limiting factor. Likely things like CPU speed for decompression played a role.

It's unclear to me how much is changed - Tom's shows that BF3 level loads go from 42 to 24 seconds moving from a 2TB Caviar Green to a 240GB Vertex 3, but I have the feeling that number would be closer together is they weren't using a Green drive - I have quite a few 2TB Caviar Greens and I don't use them to run apps generally.

(Also, in regards to a few of the posts here: waiting for apps to load may be a PITA, but so is dealing with removable storage if you actually use your laptop on the move a lot.)