Seagate Launches Hybrid SSD Hard Drive 224
MojoKid writes "Though there has been some noise in recent years about hybrid storage, it really hasn't made a significant impact on in the market. Seagate is taking another stab at the technology and launched the Momentus XT 2.5-inch hard drive that mates 4GB of flash storage with traditional spinning media in an attempt to bridge the gap between hard drives and SSDs. Seagate claims the Momentus XT can offer the same kind of enhanced user experience as an SSD, but with the capacity and cost of a traditional hard drive. That's a pretty tall order, but the numbers look promising, at least compared to current traditional notebook hard drives."
Hmmm... (Score:1, Interesting)
Wouldn't it be cheaper and more effective just add an additional 4 GB of memory for disk cache?
ReadyBoost in hw? (Score:5, Interesting)
Or wait.. (Score:3, Interesting)
OCZ and im sure others have SSDs up to 500GB now. OK, they cost as much as my car, but they exist. It wont be long before they get up to 1TB, then 2TB.. Then its just a matter of waiting for the price to come down.
SSDs have caught up to traditional drives capacity extremely quickly, it wont be long before you can put a 10TB SSD in your laptop and never have to worry again (well, except for loosing it).
RTFA (Score:4, Interesting)
The trend continued in the remainder of the PCMark Vantage tests. On the first run of the benchmark, the Seagate Momentus XT performed surprisingly well. By the third run though, performance had increased dramatically and approached the level of the true SSD.
We should also point out that we ran this test numerous times, and after the third run, the additional performance increases stopped, which is to say Run 4 performed like Run 3. The screenshots of the actual Vantage performance summaries are available in the image gallery at the bottom of the page for those that would like to see the progression from Run 1 through Run 4.
So, it is slightly more expensive than a high performance disk drive, and offers most of the performance of an SSD. Most room on hard drives is taken up by massive media files, which do not need to be accessed at top speed because they are usually streamed for playback.
Eventually the the best drives will allow you to designate a folder for SSD storage only. Video editors should be able to buy a 1TB/32GB SSD drive and have a folder for the files they are currently editing. This may not be necessary if the drive intelligently identifies open files and transfers them to the SSD portion.
And I don't think this is just a big cache. I'm pretty sure hard drive caches disappear upon reboot.
Software / OS hacks (Score:5, Interesting)
Seems like you could do better if you simply could reorder the files on your traditional hard disk so that you'd get 100% readahead buffer hits. If properly optimized this way, your traditional hard disk should always be transferring near the max block read rate of ~100MB/s
I'm guessing this is what some of the boot profilers / optimizers are doing.
The readahead utility used by Redhat / Fedora (and also available for Debian) gives you some benefit loading lots of small files from the disk by reordering reads by inode number to minimize head seeks. The next major benefit would be if it could actually reorganize all those files into a single tarfile, and maybe even compress it a bit, so it can do a single large block read to get all that content off of disk and into RAM cache.
This is the wrong place for this optimization (Score:3, Interesting)
Filesystems have a much better idea of what data is going to be used frequently. This is an optimization they should be making. Seagate can make some good guesses by looking at block-level IO statistics, but that's like trying to optimize bytecode, all the really useful information is gone by the time you get to block-level IO.
I think hardware vendors should be supporting more interesting experimentation on the filesystem front instead of coming up with proprietary hacks like this that are basically a half solution.
Re:Or wait.. (Score:3, Interesting)
Re:This is the wrong place for this optimization (Score:5, Interesting)
What if this drive could show up as two devices and a control driver and the driver allows a very fast copy between the two (without using SATA to the mobo)? SCSI has control drivers, used for scanners, tape libraries, etc. It wouldn't be to hard to graft a few controls into this drive and then have out of band front-line to nearline migration that happens on the disk autonomously.
Samsung already did this. (Score:4, Interesting)
I have one of the old Samsung drives from 2007, a 80GB with 256MB of flash.
http://en.wikipedia.org/wiki/Hybrid_drive [wikipedia.org]
http://www.samsung.com/us/consumer/office/hard-disk-drives/hybrid-hdd-flashon/HM08HHI/index.idx?pagetype=prd_detail [samsung.com]
Re:4GB? (Score:3, Interesting)
Well... maybe. NAND flash isn't too many generations away from hitting a lithography wall from what I remember. And we're still 10x-20x more expensive then magnetic media on a $/GB measurement. 2.5" laptop drives are in the 0.14-0.17 $/GB range, while SSDs are still up in the 1.36-2.34 $/GB range.
Assuming that we're already down in the 40-50nm(?) range for flash media, can they really manage to squeeze one more order of magnitude out of the feature sizes? (Closer to 3x smaller features since you double the bits at sqrt() feature size.) If they can make NAND flash down at 10-15nm, then yes we might see $/GB prices below $0.20.
25nm is apparently around the corner, so we might see a 2x-4x price improvement soon. The question is how much headroom is left after that.
Re:4GB? (Score:3, Interesting)
What makes this special is not just that it has a cache. Every HDD out there has a cache. This puppy has a "cache" 100x what current drives have.
I think it's silly. The NAND will wear out really quick, and there doesn't seem to be much of a performance boost over a fast WD Black. Actually, there's no performance boost - but it is a smaller form factor that fits in laptops.
I remember a few years back a (Japanese?) company paired 1-2GB of cache with a 5400RPM HDD. They completely maxed out SATA1's transfer speeds - faster than the fastest WD Black released today. (The 2TB one)
If we had HDDs with 2GB of cache rather than 32-64MB, our drives would be a lot quicker. Quite possibly comparable to SSDs in sequential read/write, and a bit higher than our current HDDs in IOPS. I'd take one simply because it wouldn't wear out like NAND does.