Seagate Momentus XT 500 GB 7200RPM SATA 3Gb/s 32 MB Cache 2.5 Inch Solid State Hybrid Drive ST95005620AS-Bare Drive
Review by G. Jagannath "GJJ" : Great Hybrid Hard Drive for SATA Notebooks

This is a great Hybrid Hard Drive. While I expected the "feel" of the drive to be much faster, I have only used the product for a few days. I do believe that bootup is peppier on my MacBook Pro running Snow Leopard. I cannot as of yet speak for the day to day running applications, although the reviews of this product were very positive including those of Anandtech and Maximum PC. I became interested in the fact that it was alone in having 32 MB of cache, quite a lot for a 2.5" SATA hard drive.

I heard lots of negative feedback from customers,but none of the problems noted have appeared for me. I do notice a bit more battery draw, but I upgraded from a 8MB cache 5400RPM hard drive. Some have complained of a ticking noise, but I don't hear it at all and my notebook is on practically all day. I would say that for people who want to get better performance and do not mind sacrificing a bit of battery life then it is really worth purchasing as an upgrade.

Seagate Momentus XT 500 GB 7200RPM SATA 3Gb/s 32 MB Cache 2.5 Inch Solid State Hybrid Drive ST95005620AS-Bare Drive
Review by Kerch : Second drive. First defective.

The Story:
Originally bought this drive from Newegg.com. Love that Newegg. Anyway, got a defective drive. Should've known something was wrong. First problem was trying to format it with my MacBook Pro via an external adapter. Drive Utility found it the first time but then kept loosing connection. The formatting took FOREVER. But I didn't know what to expect with a hybrid drive. Tried going ahead and installing it, which is no easy task on the MacBook Pro unibody. Same problems but still got the OS installation going. Now that's fixed. But it was a bit on the noisy side. Again, didn't know what to expect with the hybrid and had read some reviews that mention this. As a precaution, I contacted Seagate via email and asked if I should be worried. They suggested that I run First Aid on it. ID'ed as a bad volume including multiple errors. Back to Newegg you go. Newegg was great with the return, as usual. I bought the replacement from Amazon and paid a tad more ONLY because I didn't want to wait for the replacement process, I messed up the RMA to be a replacement (which Newegg chat helped to fix), and I have Amazon Prime and paid only $4 for overnight shipping. Sooooooo...... Got hard drive #2, tested on external adapter with absolutely no problems at all. Even did the OS install while connected externally and booted to the drive as external. Worked GREAT even like this. Then went through the lengthy installation into the MacBook Pro. Works great! AND ITS QUIET!

The Review:
So here is my take so far on the Seagate Momentus XT 500GB Hybrid drive. Regularly used programs start super fast. Shutdown and startup are fast. Now the first time you shutdown and start up the computer you won't see a difference. But after that the drive adapts to it and starts using the Flash Memory. Same is true with the programs. Though you may find that the programs load and use times don't increase until 2-3 uses. Of course, I use Safari 4.0 most of all. Starts up lightening fast. I use Entourage 2008 and Photoshop CS4 equally second. Entourage can lag at loading typically. With the Momentus XT it's much faster. Photoshop now, that's a HUGE difference. It loads in maybe 1/4 of the time it did before. And that maybe selling it short, maybe faster. So, I like it. Does what it says it's suppose to do. I guess sort of like having an SSD drive (though I've never had one to compare them) but without the big price tag.
Seagate Momentus XT 500 GB 7200RPM SATA 3Gb/s 32 MB Cache 2.5 Inch Solid State Hybrid Drive ST95005620AS-Bare Drive

Seagate Momentus XT 500 GB 7200RPM SATA 3Gb/s 32 MB Cache 2.5 Inch Solid State Hybrid Drive ST95005620AS-Bare Drive
Review by Ankush Narula : Momentus XT SD23 Problems with mid-2009 MacBook Pro 13"

I have a mid-2009 13" Macbook Pro with 8GB RAM. The stock hard disk was a 320GB 5400RPM Hitachi which is a fine drive. But we all know that the biggest bottleneck in a personal computer is the slow mechanical hard disk drive. For a long time, I had considered getting an SSD. However, I didn't want to sacrifice capacity for performance since larger SSD drives can be extremely costly. So like many others, I eagerly awaited the release of the Seagate Momentus XT 500GB drive with the 4GB of SSD read-buffer. Such an exciting and clever idea! Finally in early October 2010, I purchased the drive from OWC, installed it and setup Mac OS X from scratch. I then migrated over all of my applications and settings.

For the first couple of days the system would freeze up, so I updated to the latest (SD23) firmware; it's still the latest firmware as of this writing. For the next 6 weeks I was pretty happy. Everything felt much snappier and responsive. However, over the past 3-4 weeks I've been experiencing sudden "freezes". I looked into the system.log (in the Console) and found a frequent message from the smartd: "[...] failed to read SMART Attribute Data". This message would typically be followed by error messages from various other applications that were experiencing the freeze and timing out. It seemed peculiar to me that the system couldn't pull SMART data from the Momentus XT since this information is stored in the electronics rather than on the hard disk itself.

I've visited the Seagate forum for Seagate Momentus XT several dozen times and read about other folks having the same troubles. The speculation amongst most of the users is that the SSD portion of the drive is overheating and also the mechanical portion is not spinning up fast enough. However, I think the problem is much worst than this if it can't read SMART data. Some people say that upgrading from SD22 to SD23 has fixed the freezing problem. However, the SD23 firmware comes at the price of much higher power consumption and much lower battery life. Even so, most people running the SD23 firmware, myself included, are still experiencing the freezing problem in addition to much lower battery life. I won't recount all of the details, but suffice it to say that Seagate has been unable to solve the problem over the past 2-3 months. Also, they've made no public admission of error nor have they offered any of us refunds.

I can't tolerate system freezes because I use my Macbook Pro in live audio situations. So I'm ditching this drive ASAP.

For those who care, my solution is that I've ordered a 100GB Pro RE SSD drive from OWC ($299). It will serve as my primary drive, housing the System, Applications and swapfile. I've also ordered the 750GB WD Scorpio Blue ($109) hard disk to serve as second internal hard disk using the OWC Data Doubler kit ($79) which allows you to install a second hard drive in place of your optical SuperDrive. Once I've setup OS X and my Applications on the SSD drive, I'll setup my Users directory on the Scorpio drive and migrate everything over from the junky Momentus XT. This solution obviously costs more than the Momentus XT, but I know it will be truly reliable and super fast. I also know that if I have trouble, OWC and Western Digital will be much more responsive and helpful.

--- UPDATE 2010-12-13 10:30PM GMT -0500 ---

A few things of note... first, I uninstalled smartmontools 5.39.1 and the frequent freezing went away. One of the commenters on this review suspects that the problem is with the mid-2009 MBP13 and not smartmontools. In any event, with smartmontools removed I still experienced issues with occasional freezing and degraded battery life - about 2 hours.

Interestingly, Seagate released the SD24 firmware on the day I wrote my initial review and it seems to be helping many people. Of course it's too early to tell but this could be good news for Momentus XT owners. Unfortunately, I've already switched to my new setup described above so I haven't had a chance to install SD24 and test it. Once I do, I will return here and update my review. In the meantime, I'm updating my rating to 3 stars since Seagate has finally shown some progress AND because the frequent freezing was due to some combination of this MacBook + smartmontools.

Seagate Momentus XT 500 GB 7200RPM SATA 3Gb/s 32 MB Cache 2.5 Inch Solid State Hybrid Drive ST95005620AS-Bare Drive
Review by ooglek : Good performance boost for the money

I've read a lot of reviews, some good, some bad. I think some people have this idea that the product will speed everything up all the time, and this sets bad expectations. What this drive will do is cache often used data, such as core Operating System files used at boot and commonly used applications, and store that data in its 4GB SSD-like cache. If your drive already reads and writes pretty fast, in the neighborhood of 75-100MBps (megaBytes not bits), other than boot up and application loading, you aren't going to notice much of a difference.

I use Apple's OS X Snow Leopard, and it definitely boots faster (1 minute 30 seconds prior to this disk, now 55 seconds from power on to ready + all my startup apps running), and commonly run applications also start up noticeably faster.

I upgraded from a bit slower drive, so I see some performance gain there, but nothing huge.

Overall I got the disk read speeds I was looking for -- faster boot, faster common app loading, and an overall boost in performance by upgrading from a slower drive altogether.

This drive won't change your life, unless you are booting several times a day or loading the same data repeatedly. It's a fine drive with the benefit of faster boot and common app loading times, nothing more.