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For vehicle drives, see .
"Solid-state hard drive" and "SSHD" redirect here. For information about solid-state drives (SSDs), see .
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In , a hybrid drive is a logical or physical
that combines a fast storage medium such as
(SSD) with a
(HDD), with the intent of adding some of the speed of flash storage to the cost-effective storage capacity of traditional HDDs. The purpose of the SSD in a hybrid drive is to act as a cache for the data stored on the HDD, improving the overall performance by keeping copies of the most frequently used data on the faster SSD.
There are two main configurations for implementing hybrid drives: dual-drive hybrid systems and solid-state hybrid drives. In dual-drive hybrid systems, physically separate SSD and HDD devices are installed in the same computer, having the data placement optimization performed either manually by the , or automatically by the
through the creation of a "hybrid" logical device. In solid-state hybrid drives, SSD and HDD functionalities are built into a single piece of hardware, where data placement optimization is performed either entirely by the device (self-optimized mode), or through placement "hints" supplied by the operating system (host-hinted mode).
A high-level comparison of SSHD and dual-drive or FCM designs
There are two main "hybrid" storage technologies that combine NAND flash memory or SSDs, with the HDD technology: dual-drive hybrid systems and solid-state hybrid drives.
Dual-drive hybrid systems[]
Dual-drive hybrid systems combine the usage of separate SSD and HDD devices installed in the same computer. Overall performance optimizations are managed
By the computer user, who manually places more frequently accessed data onto the faster drive.
By the computer's
software, which combines SSD and HDD into a single hybrid volume, providing an easier experience to the end-user. Examples of hybrid volumes implementations in operating systems are
on , and Apple’s
based implementations on OSx.
By chipsets external to the individual storage Drives. An example is the use of flash cache modules (FCMs). FCMs combine the use of separate SSD (usually an
SSD module) and HDD components, while managing performance optimizations via host software, , or a combination of both. One example is Intel
(SRT), which is implemented through a combination of certain Intel chipsets and Intel storage drivers, is the most common implementation of FCM hybrid systems today. What distinguished this Dual Drive system from an SSHD system is that each drive maintains its ability to be addressed independently by the operating system if desired.
Solid-state hybrid drive[]
Solid-state hybrid drive (also known by the
SSHD) refers to products that incorporate a significant amount of NAND flash memory into a
(HDD), resulting in a single, integrated device. The term SSHD is a more precise term than the more general hybrid drive, which has previously been used to describe SSHD devices and non-integrated combinations of
(SSDs) and hard disk drives. The fundamental design principle behind SSHDs is to identify data elements that are most directly associated with performance (frequently accessed data, boot data, etc.) and store these data elements in the NAND flash memory. This has been shown to be effective in delivering significantly improved performance over the standard HDD.
An example of an often confused dual-drive system being considered a SSHD is the use of laptops which combine separate SSD and HDD components into the same 2.5-inch HDD-size unit, while at the same time (unlike SSHDs) keeping these two components visible and accessible to the operating system as two separate hardware devices
In the two forms of hybrid storage technologies (dual-drive hybrid systems and SSHDs), the goal is to combine HDD and a faster technology (often NAND flash memory) to provide a balance of improved performance and high-capacity storage availability. In general, this is achieved by placing "hot data", or data that is most directly associated with improved performance, on the "faster" part of the storage architecture.
Making decisions about which data elements are prioritized for NAND flash memory is at the core of SSHD technology. Products offered by various vendors may achieve this through device , through device drivers or through software modules and device drivers.
Self-optimized mode
In this mode of operation, the SSHD works independently from the host operating system or host device drives to make all decisions related to identifying data that will be stored in NAND flash memory. This mode results in a storage product that appears and operates to a host system exactly as a traditional hard drive would.
Host-optimized mode (or host-hinted mode)
In this mode of operation, the SSHD enables an extended set of SATA commands defined in the so-called Hybrid Information feature, introduced in version 3.2 of the
(SATA-IO) standards for the SATA interface. Using these SATA commands, decisions about which data elements are placed in the NAND flash memory come from the host , device drivers, file systems, or a combination of these host-level components.
Some of the specific features of SSHD drives, such as the host-hinted mode, require software support from the operating system. Microsoft added support for the host-hinted operation into , while
are available since October 2014, pending their inclusion into the .
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by . Unsourced material may be challenged and removed. (November 2013) ()
Hybrid-Drive technology has come a long way with modern implementations improving over the past decade beginning in 2007:
introduced the first hybrid drives with the Seagate Momentus PSD and Samsung SpinPoint MH80 products. Both models were 2.5-inch drives, featuring 128 MB or 256 MB NAND flash memory options. Seagate’s Momentus PSD emphasized power efficiency for a better mobile experience and relied on Microsoft Vista’s . The products were not widely adopted.
In May 2010, Seagate introduced a new hybrid product called the Momentus XT and used the term solid-state hybrid drive. This product focused on delivering the combined benefits of hard drive capacity points with SSD-like performance. It shipped as a 500 GB HDD with 4 GB of integrated NAND flash memory.
In November 2011, Seagate introduced what they referred to as their second-generation SSHD, which increased the capacity to 750GB and pushed the integrated NAND flash memory to 8 GB.
In March 2012, Seagate introduced their third-generation laptop SSHDs with two models – a 500GB and 1TB, both with 8GB of integrated NAND flash memory.
In September 2012, Toshiba announced its first SSHD, delivering SSD-like performance and responsiveness by combining 8GB of Toshiba’s own NAND flash memory and innovative, self-learning algorithms with up to 1 TB of storage capacity.
In September 2012,
(WD) announced a hybrid technology platform pairing cost-effective MLC NAND flash memory with magnetic disks to deliver high-performance, large-capacity integrated storage systems.
In November 2012, Apple released the factory-configured Dual-Drive Hybrid System named .
In April 2013, WD released 2.5-inch WD Black SSHD products, including a 5 mm–high SSHD with 500GB of storage capacity and NAND flash memory size options of 8 GB, 16 GB and 24 GB.
In October 2015, TarDisk Introduced the plug-and-play Dual-Drive hybrid system, "TarDisk Pear" with flash memory size options upto 256GB.
Late 2011 and early 2012 benchmarks using an SSHD consisting of a 750 GB HDD and 8 GB of NAND cache found that SSHDs did not offer SSD performance on random read/write and sequential read/write, but were faster than HDDs for application startup and shutdown.
The 2011 benchmark included loading an image of a system that had been used heavily, running many applications, to bypass the performance advantage of a freshly- it found in real-world tests that performance was much closer to an SSD than to a mechanical HDD. Different benchmark tests found the SSHD to be between an HDD and SSD, but usually significantly slower than an SSD. In the case of uncached random access performance (multiple 4 KB random reads and writes) the SSHD was no faster than a comparable HDD; there is advantage only with data that is cached. The author concluded that the SSHD drive was the best non-SSD type of drive by a significant margin, and that the larger the solid-state cache, the better the performance.
The initialism could be interpreted as "solid-state hard drive", although it is more commonly interpreted as "solid-state hybrid drive".
Petros Koutoupis (). . <.
. Macworld.
Dong Ngo (9 January 2013). . CNET. CBS Interactive 2015.
. PCWorld.
+Peter Paul. . The Best Laptops 2015.
(PDF). . p.&#160;2.
Andy Herron (2013).
Michael Larabel (). . .
Jason B. Akers (). . .
Perenson, Melissa. . PCWorld 2013.
. Seagate Technology, LLC 2013.
Liszewski, Andrew. . Gizmodo.
Patrick Schmid and Achim Roos (). .
Anand Lal Shimpi (). .
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官方公共微信Tested: PlayStation 4 Hard Drive vs. SSD vs. Hybrid Drive - Tested
The PlayStation 4's built-in storage drive is more important than ever, but the 500GB hard drive included with the next-gen console is slow to install and load games. Good thing it's easily replaceable. We test the benefits of replacing it with an SSD and a hybrid drive (SSHD) to see what difference a $100 upgrade can make.AcomData E5 HybridDrive External Hard Drive
1.23 GB! That's what my 250 GB media storage hard drive showed after downloading all my newborn baby girl's photos to it. And I haven't started transferring the one hour digital video of her yet, which is going to take another 12 GB of space.
So, on the way home, I stopped by Fry's Electronics to take a look at their hard drive selections. A 500 GB drive was the best bang for the buck at that moment. On that day, the AcomData 500 GB external USB HybridDrive was the best value. I picked up one for now. If it's any good, I'd pick up another one for backup. Here is my review.
In the Package
After getting home, I unpackaged the drive. The external case is made out of hefty shinning aluminum alloy. It's really quite very high-tech. The package included an attachable stand, adhesive rubber feet, USB cable, AC adapter and power cord, CD-ROM, printed user抯 guide (English and French), and mail-in product registration card.
The USB cable has a Type A connector on one end for connecting to your computer. The other end of the cable is a Type B connector for plugging into the drive. The Type B connector looks like a house and is commonly found on USB printers.
The AC adapter has a proprietary four-pin plug. This plug provides separate 5V and 12V power and ground. That's the first time I've seen an USB enclosure with separate voltage source. I had hoped that it was a basic power plug so that I can source a power adapter in the future if necessary. This proprietary AC adapter ruined my plan.
Hardware Operation
An small on/off switch is in the back of the drive. The hefty USB enclosure is a good sound insulator. The drive emitted no noise when powered on. You'll only know that it's on if you place your hand on the drive or the table that the drive is sitting on. You can only feel the vibration of the 7200 RPM drive spinning. A cool blue button on the front of the drive also lights up to give you an indication that the drive is on.
Software Operation on Microsoft Windows XP
Plugging the external hard drive into a Windows XP computer causes the Windows Hardware Manager to automatically install the driver as USB Mass Storage Device. However, the E5 HybridDrive seems to play some tricks with it. Because an additional 122 MB CD drive shows up first. An instructional dialog box pops up to explain that the drive is password protected from the factory. The default password is "12345". You can log-in, change the password, or disable the password manager. I choose to disable the password manager for now, hoping to verify my new 500 GB drive first.
After getting pass the password stage, it took 27 seconds (on a dual core notebook) for the actual hard drive to mount and show up in Windows Explorer. At first, I thought the computer had hung. But patience paid off. As soon as the hard drive shows up in Windows Explorer, a dialog box asks whether you want to activate the Nomad Mobile Desktop (see screen shot below).
I'm more of a power-user and really had no intention of using any of the software that came with the drive. I just want an empty hard disk to store my data. So I canceled the dialog and proceeded to look at the content of the drive. The drive is divided up into two partitions: 1) CD PART and 2) HD PART. The CD PART is a 122 MB partition, while the HD PART is a 465 GB partition (see screen shot below).
Only 465 GB shows up instead of 500 GB because hard drive manufacturers plays on the definition of a gigabyte. Personally, and technically, that's fraud. Because computer system bases everything on the power of 2's. Therefore, by Computer Science definition, 1 KB = 1024 bytes, 1 MB = 1024 KB, 1 GB = 1024 MB. Therefore, 1 GB actually equals 1,073,741,824 bytes. By definition, 500 GB equates to 536,870,912,000 bytes. But the hard drive manufacturers defrauds us by giving us a drive that could store 500,000,000,000 bytes and calling it a 500 GB drive. It's fraud, because 500,000,000,000 is not 5 GB by definition. Unfortunately, you won't find a honest hard drive manufacturer using the real definition in today's marketplace.
Software Operation on SuSE Linux 9.0
I tried the AcomData 500 GB HybridDrive on SuSE Linux 9.0. At first, I suspected that Linux would not recognize the drive due to the partition trick it uses. I was dead wrong. SuSE Linux 9.0 recognized the virtual CD-ROM drive and the FAT32 partition right away. Mount time was less than a few seconds, far faster than the Windows XP mount time.
All files on the virtual CD and the hard disk partitions were recognized, readable, and writable. I had no problem using this drive on Linux at all!
I tested the drive on Linux when the password functionality is already disabled. I suspect Linux will not be able to mount the drive if the password functionality is enabled.
Built-In Password Protection
Despite the fact that I'm a power-user and had no intention of using any of the bundled software that came with the drive, I thought the password protection is implemented rather well. And I may potentially take advantage of it.
Nothing needs to be installed on your computer system itself for yuo to use the pa everything runs from the external hard drive. When you plug it in, the password manager will automatically show a login screen. Only after successfully logged in will the larger data partition (HD PART) be mounted.
The password system uses SHA-256 encryption. As the name imply, it is a 256-bit encryption that makes breaking it with today's technology very difficult. Based on the manual, "it is so secure, in fact, that if you forget your password you will simply never be able to access the stored data. The data is effectively lost. Luckily, you'll have a password hint to help you remember."
If you really do forget your password, there is no way to recover the data on the drive. You can reset the password and the drive for re-use, but the reset functionality will completely reformat the hard drive partition, causing all data to be erased. It seems to be a very secure way to save your data, but you have to figure out a way to never forget your password.
Unfortunately, this password protection feature is probably not compatible with non-Windows and non-Mac operating systems. If you use Linux, like I do, you might potentially have trouble accessing this drive, even if the password functionality is disabled.
Media Storage
The whole purpose of going with this AcomData 500 GB external drive is to provide media storage for my library of photographs and videos. After getting pass the security features and by-passing other built-in software, I found a
empty 465 GB drive for my use.
Copy all the data from my existing 250 GB drive should be a no brainer. I plugged in the 250 GB drive into my spare USB port so that I can do a drive-to-drive copy. When both drive showed up in Windows Explorer, I dragged all the files from the 250 GB drive onto the new AcomData drive. Windows XP started copying everything over. Nothing could go wrong at this point, right?
For some reason, Murphy's Law always kicks into play when I'm dealing with computers. Two hours into copying the files, Windows Explorer reported that the destination drive has ran out of space. Huh? But at the point, only 100 GB of space has been used. There are 365 GB of space left. Baffled, I tried again. Same message. After 10 minutes of scratching my head, I looked at the file that it failed on. It's a one-hour raw DV footage that took up 12 GB of space.
That's when I remembered that there is a max size limit on individual files. The AcomData 500 GB drive comes pre-formatted to FAT32, which has a max file size limit of 4 GB! FAT32 is definitely insufficient for media storage. I looked at the partition format on the 250 GB drive. It's been formatted to NTFS, which has a 2 TB max file size limit. If you are going to use the drive for media storage, make sure you format it the drive to NTFS.
AcomData manual mentions that only FAT32 is fully compatible with Windows 98 SE, Me, 2000, XP, and Mac OS. When you format the drive to NTFS, you will loose compatibility with Mac and older operating systems. Looks like being a cinematographer means you will have to loose portability between operating systems.
Apparently, on Windows 2000 and XP, it's not even possible to format a drive to FAT32 if the drive is bigger than 32 GB. In the end, I formatted the 500 GB AcomData HybridDrive to NTFS. I was able to transfer all my media files over to the HybridDrive in NTFS format. I've noticed that the mount time for the NTFS is only 5 seconds (compare to 27 seconds for FAT32).
Conclusion
Other than the multi-step mounting process and the long mounting time, the external hard drive works very well in Windows XP. The built-in password protection functionality is very tempting for me to try. Even though it does sound dangerous, it seems very secure for my photos, videos, and other personal data.
I've recently found that the Fantom Drives 500 GB Titanium II External USB 2.0 Hard Disk Drive uses the same enclosure as this AcomData E5 HybridDrive. The Fantom drive has a standard SATA-to-USB interface without the fancy CD PART and HD PART partition. If you just want a 500 GB hard disk with the password security, the Fantom drive is the way to go. See my review in the "Related Links" section below.
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