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Seagate Announces First SSD, 2TB HDD
Lucas123 writes "Seagate CEO Bill Watkins said today that the company plans to put out its first solid state disk drive next year as well as a 2TB version of its Barracuda hard disk drive. Watkins also alluded to Seagate's inevitable move from spinning disk to solid state drives, but emphasized it will be years away, saying the storage market is driven by cost-per-gigabyte and though SSDs provide benefits such as power savings, they won't be in laptops in the next few years. A 128GB SSD costs $460, or $3.58 per gigabyte, compared to $60 for a 160GB hard drive, according to Krishna Chander, an analyst at iSuppli. 'It will take three to four years for SSDs to come to parity with hard drives,' on price and reliability."
Every news source has merged those two statements together, and every time, my brain gets stuck on it.
Seagate is announcing two seperate products. One is a SSD and the OTHER is a 2TB hdd.
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Just found out that hybrid drives are already in the market. http://www.engadget.com/2007/03/07/samsungs-hybrid-hard-drive-hhd-released-to-oems/
They called me mad, and I called them mad, and damn them, they outvoted me. -Nathaniel Lee
Ha! I can remember having to order the installation of a new 220V electrical circuit to support the installation of a rack-mount winchester 450 MB hard disk drive. You needed at least two people to lift the drive enclosure off the floor. The new electrical circuit was needed to supply enough current for the drive to spin up. We used 10 MB removable hard disk cartridges that were about the size of a large pizza to store the operating system and user programs.
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Vista offers a spec to drive makers called the ReadyDrive, or a hybrid hard disk which combined some flash memory with a mechanical hard disk, to allow the drive to immediately write contents somewhere permanent, which boosts performance and allows the drive to schedule the optimum way to write out data as opposed to writing one chunk, waiting for the platter to spin around for another segment, then back to the first.
The only hybrid drive I see is an 80 gig seagate though, although there are likely more offerings.
Spot on. Making a hard disk for a competitive price is hard. Thats why there are only a handful of hard disk manufacturers. Making a circuit board with some chips on it can be done by hundreds of companies all over the world. I cant think of any reason to buy a Seagate SSD over any one of the other hundreds of competitors, especially when they all have the same electronics inside.
Separately, it's nice to know that analysts agree with research I've done that it's only 4 years before SSD surpasses HD, at least in 2.5 inch drives. I've been comparing the relative price improvement of hard disk prices to flash and its pretty easy to estimate a crossover point.
You can have a look at my data (charts) and conclusions here. http://www.mattscomputertrends.com/flashdiskcomparo.html
is very dependent on the application. In particular it depends on the mix of linear vs random operations and the mix of reads and writes.
For 100% read applications SSDs tend to be similar in performance to hard disks when reading linearly, and a lot faster than hard disks when reading randomly. This shows up in linear read speeds of 100 MB/sec for a typical Flash SSD which is "close" to a hard disk. For random 4K reads, Flash SSDs can stomp any hard disk. Most disks are in the 10,000 4K read IOPS range where 15K SAS drives are in the 250 range or 40x slower. So for applications that are 100% read SSDs can be as much as 40x faster, although the average is usually in the range of 15x to 20x.
When you start writing to Flash things get interesting. Flash is really designed for large, linear, aligned, writes. With most drives, you can get maximum write throughput only if you write exactly aligned with the drives internal erase blocks. Thus you can write exactly 2 megabytes on exact 2 megabyte drive boundaries and get 100% of the theoretical write throughput of the drive. Unfortunately, no application acts like this, so you are at the mercy of the file system and Flash controller to turn your smaller, probably random, and probably mis-aligned writes into what the drive can handle. The net impact of this is that good Flash SSDs have 4K random write IOPS in the 120s which is 1/2 the speed of a 15K SAS drive. I have measured Flash SSD with 4K write IOPS with values like 135, 120, 64, 43, 24, 13, 4.0, and 3.3.
This is why Flash SSD performance is so hard to judge. The random write performance can suck up the available "drive time" and dig a system deep into dirty buffer flushing. We talked with one Dell laptop user that described their system becoming "unusable" while an Outlook indexing operations was randomly updating a big file. Unusable in this case was 2+ minutes for to bring up task manager.
These random writes also have a real impact on the wear of the drive. Every time you seek a write, you basically chew up a write/erase cycle, even if the write is only 4K long. If you look at a drive that claims 50 GB/day for 10 years, this is 50 GB of linear writes on exact erase block boundaries. If you write 4K randomly, the 50 GB really means 25,000 4K writes or 100 Megabytes of random writes.
The solution to this is to not write randomly to the drive. There are file systems designed for Flash that address these issues. These are typically called "Log File Systems". Unfortunately, there is no generally available file system really designed for performance. In Linux the LogFS options are really tuned for small memory small storage systems and for hardware where the flash chips are directly accessible. They do help drive wear a lot, but they are just not tuned for Gigabytes of space or database crunching performance.
Another solution is my companies product called MFT (Managed Flash Technology) which is a software block mapping layer that runs on the host. It gives you the random write performance benefits and wear benefits of a LogFS while allowing you to use whatever file system you wish. MFT was developed on 2.6 Linux and has been ported to Windows. With MFT, the same drives that do 25 4K random write IOPS usually measure over 10,000. The linear speed of the drive is still equal to a hard disk, but the random speed is now closer to symmetric with reads and writes. Thus jobs like updating databases can literally run 20x faster than the fastest hard disks.
In the end, Flash SSDs will find specific markets initially. I can say with certainty that they won't get used for off-line backups or storing/edit large quantities of HD video. But give them databases or file systems with lots of small files, and they can really smoke a hard drive.
With hot file adaptive clustering ( http://developer.apple.com/technotes/tn/tn1150.html#HotFile )
Basically, read only often accessed files are moved to the zone on hard drive where the access to files is fastest.
It would not be hard to adapt this behaviour to move the files onto SSD portion of the disk at all.
As the island of our knowledge grows, so does the shore of our ignorance.