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Hard Drives vs. Flash SSDs

Next-Gen 7,200 RPM Notebook Hard Drives
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We’ve been looking at the flash SSD market for quite a while, which has solutions that deliver up to 130 MB/s of read throughput. The next generation, as announced by companies such as OCZ and Intel, is going to offer up to 200 MB/s of read throughput and higher capacities. Still, it remains questionable as to whether or not these new products will be able to provide balanced performance. This means that write performance, access time, and I/O performance must be at levels comparable to the impressive read throughput, and they should also deliver on the promise of reduced power consumption at the increased capacities.

Flash Characteristics

Flash SSDs do not have any cache memory, since the flash cells are typically fast enough to turn simple DRAM cache into a useless feature—the transistor-based technology ensures that access times are almost nonexistent. While conventional hard drives take between 5 and 25 milliseconds to locate and access stored blocks, all content on a flash SSD can be accessed directly and nearly instantly. As a consequence, flash SSDs are not only fast to find data, they do not require defragmentation. (In fact, defragmentation increases the wear of the flash memory cells, which only allow for several thousand read/write cycles.) While long-time studies still aren’t available, the life span of a flash SSD should at least be in the same range as the component design life for mechanical hard drives, which typically is five years.

MLC vs. SLC

Flash SSDs have the potential to easily outperform any conventional hard drive by delivering much higher read throughput. Write throughput and access time depend on the flash technology that is used: multi-level cell flash (MLC), stores several bits per cell, making it cost-effective, but slower. In contrast, single-level cell flash (SLC), is faster but more expensive.

Flash Loses the Cost Comparison

For the time being, conventional hard drives will still win every comparison with flash SSDs once cost and capacity are added to the equation. Most SSDs are still limited to 32 and 64 GB capacities, and if you go for fast SLC flash drives, the price tag will have more than three digits. MLC-based flash reaches 128 GB today, which can be considered an acceptable capacity, but not all of these drives can be recommended, as they usually have some disadvantages like low power efficiency or slow write performance.

On the other hand, conventional hard drives offer up to 500 GB of capacity today, and are holding up rather well when it comes to throughput, as you will see in the benchmark section of this article. Access times are an issue, though: HDDs can’t compete here. However, many HDD products are much more efficient than previous generations, and price is the killer argument. A 320 GB conventional drive costs less than $100, and if you go for high performance at low cost, you can get 80 to 120 GB at 7,200 RPM for less than $70.

Editor’s Note: The following storage stories shed additional light onto the mechanical vs. SSD issue.

Flash SSD Update: More Results, More Answers We found that many Flash SSDs do not deliver on their promise of being power efficient. The latest generation, however, manages to combine performance end efficiency impressively. Even so, Flash SSDs don’t offer sufficient capacity to actually store more than your operating system plus applications and the basic files you might need.

Will SSDs Take Over The Enterprise? Eight Memoright state-of-the-art Flash SSDs battle Seagate’s Cheetah 15K.5 and Savvio 10K.2 in RAID configurations. Flash SSDs turn out to be far superior when it comes to I/O-intensive workloads, while they don’t necessarily beat mechanical hard drives when it comes to throughput.

Memoright SSDs: The End of Hard Drives?

Install a Solid State Drive in Your Notebook

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  • -4 Hide
    thomasxstewart , August 29, 2008 12:10 AM
    Very good article, yet wonder why RAID would be used, as raid primarily increases speed by using additional platters to reduce access time. as SSD has NO Platters, NO RAID Increase. For mirroring, its merely expensive loss, as unlikely to wear out before entire system wears out. Special external disk would suffice for mirroring.

    Signed:p HYSICIAN THOMAS STEWART VON DRASHEK M.D.
  • 0 Hide
    Anonymous , August 29, 2008 2:07 AM
    Not sure where you got the mention of raid from in the article, but regardless, RAID has nothing to do with platters. Its simply how data is dealt with across multiple DRIVES.

    With SSD's you get a pretty big performance increase from using raid-0. It works the same as with a hard drive with data being split amongst the two drives so less time is needed to write and read since the work is being divided.

    Just google SSD and Raid and you'll find better examples and benchmarks.
  • 0 Hide
    Anonymous , August 29, 2008 2:17 AM
    I'm surprised that the lack of encryption on most of the drives wasn't mentioned in the conclusion. It's a deal breaker for every drive mentioned except the Hitachi, unless you plan to leave your laptop locked to a desk.
  • 0 Hide
    Luscious , August 29, 2008 2:28 AM
    That Seagate drive sound like an amazing upgrade for something like the HP mininote. I sure hope some speedy 500GB drives arrive next.
  • 1 Hide
    Anonymous , August 29, 2008 2:55 AM
    It would have been nice if the prices & performance charts were also given in the conclusion. Maybe it's there somewhere in the middle pages, but I really don't have time to read 17 pages. Most of the time it's just the first and the last pages.
  • -1 Hide
    thomasxstewart , August 29, 2008 2:55 AM
    thanks for reply, RAID was added after article was posted & its here:

    Eight Memoright state-of-the-art Flash SSDs battle Seagate’s Cheetahhttp://en.wikipedia.org/wiki/Cheetah 15K.5 and Savvio 10K.2 in RAID configurations. Flash SSDs turn out to be far superior when it comes to I/O-intensive workloads, while they don’t necessarily beat mechanical hard drives when it comes to throughput.

    I read it fast & comparison is to HDD Raid. Opps, its on p.3 bottom & just glanced as read it as admendium.Basic point is still SSD works without RAID better than HDD.I just was trying to State SSD ?isn't RAID, unless it is & might be worse for it?. NEXT:

    In theRegisture few weeks ago Server SSD was listed with pics of in production SSD that cut 4.5 Gb/s data output. I thought, how powerful, what is this? Well, while watching obama I got idea. first new SSD is DDR2, so how could that be SSD or even drive & lets face it at 4.5 gb/s who needs work divided? yet heres what I thought up: That new SSD that is so powerful & server & DDR2 cann't be turned off. That would work. turn it on, load it up & leave it running. 4.5 gb/s from one SSD. BTW i once before mentioned SSD RAID being NOT same as Platter RAID & I got same answer you gave today, so maybe its possible, yet Stats are next step.
    Whole thing is proof, NEVER TURN YOUR BRAIN OFF. Hahahaahhh.

    Signed:p HYSICIAN THOMAS STEWART VON DRASHEK M.D.
  • 0 Hide
    Anonymous , August 29, 2008 4:46 AM
    i install SSD and yes boot time faster and applications run faster but only if you work with one at the time. If two or more you feel like 10 years ago working on P4 or P3
  • 1 Hide
    Anonymous , August 29, 2008 5:06 AM
    I like the review but don't agree with the conclusion. The WD 3200BEKT is faster in every non synthetic benchmark. The Seagate 7200.3 is only the fastest in synthetic benchmarks. So if you're after real life performance go for the WD. Check the review on Techreport for more information.
  • 0 Hide
    Anonymous , August 29, 2008 4:34 PM
    Hitachi, Samsung, Seagate and Western Digital send their latest high-performance notebook drives into battle, fighting for the ultimate balance between performance and efficiency.

    Next-Gen 7,200 RPM Notebook Hard Drives : Read more
  • -2 Hide
    NotSoParanoid , August 30, 2008 1:58 AM
    I agree with the poster that said encryption is a must for portable devices -- only a complete moron would walk around with an unencrypted notebook these days. Encryption is now a *fundamental* requirement for not only government agencies, but also most companies. So the comparison as it stands is fundamentally flawed. the tests should be repeated with the hardware encryption enabled on the Hitachi drive and a comparable AES full disk software based encryption running on the others to give us an idea how the drives would perform in a real usage scenario.
  • 0 Hide
    Anonymous , August 31, 2008 1:07 AM
    I agree with the other post, in that encryption should results should have been included in the results. I am looking to upgrade my laptop hard drive and after having a laptop stolen last year, my next drive will be one that has full hardware encryption. THG, please start including benchmarks and reviews of drives with encryption. Thanks, appreciate your work.

    Mike
  • 0 Hide
    TakeyMcTaker , September 1, 2008 8:05 AM
    Why would encryption hardware need to be a part of the hard drive? It is better for the BIOS to take care of the encryption/decryption, and key entry at boot time. That existing BIOS feature makes encryption a moot point for a performance article like this. You guys are just buying the wrong notebooks, if you need encryption on the hard drive.
  • 0 Hide
    NotSoParanoid , September 1, 2008 8:01 PM
    I am aware of no "BIOS Encryption" which is certified by NIST as secure under FIPS-140-2. There are certified encrypted drive solutions. When someone delivers a certified BIOS encryption I'll consider it -- though there is a risk: with an encrypted drive, if the original machine fails and I know the keys, I can recover by simply installing the drive in a new system. With "BIOS Encryption" the drive is tied to exactly one machine. Better have good backups. ;-)
  • 0 Hide
    djfourmoney , September 2, 2008 5:15 AM
    Just in time for PS3's....
  • -1 Hide
    Adam03 , September 3, 2008 10:12 PM
    I am not interested in mechanical drives any more - they are yesterday's technology. Give me SSD at its full potential. Mechanical drives will soon become yesterday's equivalent of the steam engine. Why do these companies bother wasting their time "tweaking" storage space on mechanical drives when we would rather get our hands on a 300 Gig SSD ?
  • 0 Hide
    Anonymous , September 17, 2008 4:50 PM
    Do I get this right?

    The WD is faster when it comes to access tme, working with small files - e.g. office files - and consumes considerably less power with DVD files (thinking of those long train rides...)? How much more battery life would that give me app. on a MacBook Pro?

    The Seagate basically is faster when it comes to handling larger files and has a lower power consumption on average?

    Does anyone have insights on the noise?
  • 0 Hide
    Anonymous , October 7, 2008 12:36 PM
    I can't find the ST9320421AS anywhere when I search for someone who has them in stock. Anyone know why?

    http://edbpriser.dk/Products/Listprices.asp?ID=466099&searchArea=products&Soegeord=ST9320421AS
  • 0 Hide
    Anonymous , October 9, 2008 5:43 AM
    The conclusions regarding the lowest idle power do not match the graphic. The wrong WD drive is shown as being the reviewed drive. The graphic shows the WD2500BEVS as being the reviewed drive with a .75W idle when the reviewed drive is supposed to be the WD3200BEKT which has the second highest idle of .97W of the 4 tested drives. The conclusion says that the WD & SG drives are both less than .8W idle which is wrong. Only the SG drive is under .8W.
  • 0 Hide
    Anonymous , November 3, 2008 1:22 PM
    All this for $99 on Newegg. Why Can't I see what I'm typing here?

    Weird.

    http://www.newegg.com/Product/Product.aspx?Item=N82E16822136280
  • 0 Hide
    kultex , November 6, 2008 8:50 AM
    very interresting and informativ article, but beside all the power and performance ratings, for me noise is the most important rating for a decision - could a add perhaps some lines for the 7200rpm drives?
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