【 Weak current College 】 solid state drives and hybrid hard drive technology differences---Power By 【 China power house network 】

Solid state hard drive

Solid state hard drive is a new hard drive application technology that was originally used high-speed SLC (single-unit, SingleLayerCell) Flash memory (hereinafter referred to as the "Flash") to manufacture. Because of the read and write Flash memory does not require traditional mechanical hard disk head movement, so use Flash to build solid state drives with low power consumption and zero work noise and the advantages of high-speed response time. However, solid state drives from SLC Flash memory capacity is small, cost than conventional hard drives higher, resulting in a solid state drive prices far better than traditional hard drives so popular. The current price of solid state hard drive 32GBSLC 5000 Yuan or so, so for the time being you cannot replace the traditional hard disk. Of course, as the future manufacturing technology matures, SLC Flash memory capacity will rise in the price is also decreasing, traditional hard drive will not be eliminated, or unknown.

And now there are manufacturers adopting a compromise proposal, which is available at $ lower MLC (multi-level cell Multi-LevelCell) Flash memory manufactured solid-state disk. Currently 32GBMLC solid-state disk prices less than $ 3000, but performance is therefore inferior than traditional hard drives a large.



Disadvantages:

Because SSD disk controller design flaws, early SSD in access use over a long period of time, it is easy to generate disk fragmentation, the resulting disk access performance extremely reduced. However since then a lot of solid state drive controller design manufacturers to improve this situation. Thus many many of today's solid state hard drive solution added bulk SDRAM cache mechanism. Price is not appropriate in today's society, solid state drives need to replace the traditional hard disk from a technical perspective, or are still in the market for some time. In this traditional hard drive vendors came up with the idea of hybrid hard drive. That is, the SSD (Flash) + traditional hard drives.

Hybrid hard drive

Tidbits: MLC and SLC difference (Flash)

In each of the MLC Flash storage unit, you can save 2bit information. Thus, in the same area, MLC Flash than SLC provides twice the amount of capacity, lower storage costs, and therefore use MLC manufacturing high-capacity solid-state disk products more effectively. However, since each MLC storage unit to hold information on more complex structures, the probability of error will increase the need for bug fixes, this action led to its performance significantly behind the structure simple SLC Flash memory. In addition, the advantages of SLC Flash is carbon number 100000 than MLC Flash 10 times higher.

In the solid state hard drive has not been common before the SLC Flash is taking the lead in application in a traditional hard drive and create a new generation of magnetic hard drives. Hybrid hard drive principle and Microsoft new generation WindowsVista (Windows7) operating system functionality similar to the "ReadyBoost", both by increasing high-speed Flash memory for data prefetch (Prefetch) to reduce the information from the hard disk read, thereby improving performance. The difference is that the hybrid hard drive Flash module direct integration to your hard disk, in theory, a new generation of hybrid hard drive can not only provide better performance, you can reduce the number of read and write to your hard disk, allowing the hard drive power consumption is reduced, in particular the laptop's battery time.

As a general mixed hard drive only the SLC Flash built-in 256MB, therefore costs are significantly improved. Hybrid hard drive at the same time also used traditional magnetic hard drive design, so there is no solid state hard drive size small.

However, some people may still have a doubt, now Flash prices so low, that mixed hard drive integration of Flash capacity only 256MB? as a matter of fact, reason and the solid state hard drive, now with Flash are NAND type, may be further subdivided into SLC and MLC. The difference between read and write times for SLC and MLC high speed ratio, but the cost is more expensive to MLC. Because the hybrid hard drives require frequent reads or writes, but also need to use high-performance Flash memory, so manufacturers generally use more expensive but faster SLC Flash, hybrid hard drive built-in Flash memory capacity is relatively small.


Seagate hard drives are about to launch hybrid (figure, and traditional alike)

Hybrid hard drive technology: upgrade system startup time, save energy, extend the average time between failures

Now combined with low-cost, high-capacity storage of composite products to substantially increase the value of your hard disk, especially on laptops and other mobile device applications. With the decline in Flash memory cost in hard drive's non-volatile flash memory, Flash memory instead of disk storage some system features that will drive high capacity and high performance and fast response, Flash save electricity and lasting advantages together, this is what we would like to say that the hybrid hard disk drive.

Hybrid hard drive features a brief analysis of the

Low power consumption electricity: according to Microsoft's estimate, using a hybrid hard drive up to a maximum of 80% of the energy savings. The reason is that hybrid hard drive can make a traditional mechanical hard disk is used to sleep, read/write and access in non-volatile Flash memory. Of course, this is not to say that your notebook power must be able to save so much. After all, the storage is not the type of system power consumption of only one variable. Current estimates are that about using hybrid hard drive enables the battery time increased to 30 minutes.

Boot faster: traditional hard disk boot, are for PC powered head 3 to 5 seconds to spin the hard drive platter, head synchronization and then start the boot process. And hybrid hard drive can not having to wait for a disk rotating in search of the correct data, non-volatile Flash memory for data access is fast. Therefore, the use of hybrid drive system, the boot speed faster than traditional PC quickly.

Extension of the average time between failures (MTBF): lessMoving parts (or the same number of moving parts but less used), equal to extend the service life and reliability of the system. The benefits in a relatively easy from a hard drive-computer disk shocks and lost data notebook more obvious.

Hybrid hard disk can be played in a particular place is Microsoft's next-generation operating system WindowsVista. Vista "ReadyDrive" feature that is designed for hybrid hard drive technology.


Microsoft hopes to such benefits and give full play to the notebook system, eventually spread to all mobile and non-mobile users of Vista. WindowsVista support fast buffer store size from 50MB to General recommendation 2GB above, at least between 128 MB and 256 MB. The contents of the buffer is not caused by power outage, you can reduce the risk of data loss.

But it is not without shortcomings, non-volatile Flash memory, similar to the typical thumb drive (thumbdrive, thumb size of external memory), has a long service life. Flash Flash will repeat many times after written completely ineffective. To address this shortcoming, manufacturers must adopt complex data write mechanism cannot repeatedly use the same memory location, but will work on average across the entire device. Or you can replace, replace Flash Flash memory manufacturers.