[lotuseclat79]

What Comes After Hard Drives?.

The ability to store and retrieve data is an important component of today's computers, as well as other modern electronic devices such as cell phones, video game consoles, and camcorders. Since their invention in the 1950s, magnetic-based hard disk drives (HDDs) have been the primary method of nonvolatile storage. However, researchers are currently developing several new and promising nonvolatile memory (NVM) technologies, but for one of them to replace HDDs within the next decade, it will be a challenge.


An opened Samsung HD753LJ hard disk drive. Researchers predict that, in 2020, hard disk drives will likely be less expensive on a cost per terabyte basis than any of the competing technologies. Image credit: Christian Jansky.

-- Tom

[dock98]

it is going to be nice when the have something a lot smaller in size with the same capabilities.

[JohnWill]

I'm seeing FLASH and other solid state technologies for use in environments that require rugged storage like portable computers and industrial applications. Hard drives seem to be well entrenched in the mass storage market right now.

[ComfortGroup_IT]

Solid state has been around for a while now. Still not to the TB (or even 500GB) storage capacity yet that I have seen though and they are quite a bit more expensive than regular HDDs, however, they are pretty much Instant. I saw a laptop with a Solid state drive running Vista. The power button was pushed and within a second it was asking for login credentials. I guess the only real drawback there is trying to get into the BIOS or getting it to boot to CD.

http://www.intel.com/design/flash/na...reme/index.htm

[JohnWill]

Well, they're really fast reading, but writing is another matter.

[ComfortGroup_IT]

Originally Posted by JohnWill

Well, they're really fast reading, but writing is another matter.

Not exactly sure where you get that information...

When it came to I/O speed, there was no match. I used ATTO Technology's ATTO Disk Benchmark v2.3.4 and Simpli Software's HD Tach v3.0.4 benchmarking utilities to perform my read/write performance tests. The ATTO benchmark software showed the OCZ had a read time of 244MB/sec and a write time of 172MB/sec. The Seagate HDD had an average read rate of 98MB/sec and a write time of 87MB/sec.

http://www.computerworld.com/s/artic...9&pageNumber=2

The SSD handily beat the HDD there.

We did see decisive performance wins by the SSD models on the file read and write tests that we use for our hard-drive testing. (The read and write tests consist of reading and writing folders of files, and searching for files on a drive.) On these tests, the SSD models bested their hard-drive counterparts in 11 out of 12 instances. Occasionally, the scores were close: On our Windows file search of 6.1GB of data, for example, the SDD Fujitsu Vista Business system notebook finished the test in 86 seconds, while its hard-drive-based twin finished the test in 100 seconds. Still, in most cases, the SSD models were dramatically faster. The most extreme example: The XP Pro Fujitsu finished our large-file reading and writing test in 199 seconds, far ahead of the hard drive-equipped model, which finished the test in 533 seconds.

http://www.ecoustics.com/pcw/reviews/134185

I guess it really all depends on what you are comparing. A 15000 rpm HDD will do better vs a first generation SSD than a 5400 rpm drive would vs a high end SSD. But even in the slowest of SSDs I have seen the average write time is 80MBps where HDD write speeds aren't much better (I believe 87MBps is what I was reading and average in the 70MBps range for notebook HDDs).

[JohnWill]

"Computerworld compared four disks, two popular solid state drives and two Seagate mechanical drives, for read/write performance, bootup speed, CPU utilization and other metrics. The question asked by the reviewer is whether it's worth spending an additional $550 for a SSD in your PC/laptop or to plunk down the extra $1,300 for an SSD-equipped MacBook Air? The answer is a resounding No. From the story: "Neither of the SSDs fared very well when having data copied to them. Crucial (SSD) needed 243 seconds and Ridata (SSD) took 264.5 seconds. The Momentus and Barracuda hard drives shaved nearly a full minute from those times at 185 seconds. In the other direction, copying the data from the drives, Crucial sprinted ahead at 130.7 seconds, but the mechanical Momentus drive wasn't far behind at 144.7 seconds."

[ComfortGroup_IT]

Neither Crucial or Ridata even rank in the top 10 SSD manufacturers (http://www.storagesearch.com/ssd-top10.html) where as Seagate (which both HDDs were from) rates in the top 3 HDD Manufacturers (Maxtor and WD being the other two). Maybe if they compared a Crucial and Ridata vs a Quantum and Adtron or the two Seagates with OCZ or Fusion-io it would make sense. And from the "test" you reference SSDs aren't statistically any faster reading data either.

"Computerworld compared four disks, two popular solid state drives and two Seagate mechanical drives, for read/write performance, bootup speed, CPU utilization and other metrics. The question asked by the reviewer is whether it's worth spending an additional $550 for a SSD in your PC/laptop or to plunk down the extra $1,300 for an SSD-equipped MacBook Air? The answer is a resounding No. From the story: "Neither of the SSDs fared very well when having data copied to them. Crucial (SSD) needed 243 seconds and Ridata (SSD) took 264.5 seconds. The Momentus and Barracuda hard drives shaved nearly a full minute from those times at 185 seconds. In the other direction, copying the data from the drives, Crucial sprinted ahead at 130.7 seconds, but the mechanical Momentus drive wasn't far behind at 144.7 seconds."

So I guess they really aren't "really fast reading" either. I mean the Crucial SSD took as long or longer to do a cold boot than the 2 HDDs tested and considerably longer for a restart than either of the HDDs. There is something flawed with these tests because I have seen cold boots and restarts of SSDs in person and have to say the HDD doesn't even come close.

[JohnWill]

I'll worry about these things when the prices come down to reality.

[new tech guy]

Imo, i beleive they need to figure out how to make solid state storage drives not have a limited write expectancy for them to become mainstream. This would really be great to have SSD in a laptop as the drive is moreso exposed to shock and sudden movement compared to that of a desktop pc.

[JohnWill]

Like I said, I see them in applications where their rugged nature is a real asset. As far as the limited write cycles, modern FLASH modules have from 100,000 to a million write cycles. Add to that the algorithms used to insure that stuff like directories aren't written continuously at the same location, and the life is probably not a real factor.

[new tech guy]

That is true, I personally think they are best suited in all laptops as they are more prone to be moved around more than an external. And it sounds like the newer types of SSD, things like fragmentation are a good thing! Now what would happen say if something was to fail on one of these SSD devices. Would they have any hope at all of data recovery or is it lost forever?

[JohnWill]

If a cell or module fails, it's dead. However, as the densities get higher, a single SSD could incorporate something like RAID-5 internally and have redundancy for the data. Since the failure mode of an SSD would be different than a hard disk, this would be a practical approach for many failures.

Of course, as with any mass storage device, having a backup is still the only real defense!

[new tech guy]

[quote=JohnWill;7002233However, as the densities get higher, a single SSD could incorporate something like RAID-5 internally and have redundancy for the data.
[/QUOTE]

Isnt this what current hard disks do to increase their storage capacity? Ive seen a few opened up and found it consisted of many platters to make up the total size of the drive. Would this just constitute fora larger size of the drive or would it double for some form of redundancy? Id imagine just size for a standard hard disk but could be mistaken.

[JohnWill]

There are too many common elements in a disk drive, and frequently a head crash on any platter gets propagated to the other platters. In addition, since there is only one actuating arm in the disk drive, and a single read channel, you can't have multiple platters reading at the same time.

It's possible (though very expensive) to have multiple read channels. There were some mainframe disks that did just that, and many drum memories had head per track electronics to offer parallel access.

With electronic disks, it's very easy to have multiple chips reading/writing at the same time, and there is no mechanical access time to any part of the memory.