Handbook of things to note about SSD

Compared to HDDs, SSDs possesses many superior advantages in terms of speed, temperature, data security and power consumption.

While the development of the CPU, graphics card at a breakneck pace, the HDD is almost just refresh yourself by increasing storage capacity. But in a few years, developers have found a new direction that is stored using solid state drive SSD .

Compared to HDDs, drives SSD owns more than advantages in terms of speed, temperature, data security and power consumption. For example, the average access time of the drive SSD is from 3.5 to 10 micro seconds remaining HDD takes 5-10 milliseconds. Easy to find, drive speed SSDfaster HDD to a hundred times. However, the current drive SSD prices still relatively high, often several times higher than HDD. If the cost of ignoring the problem, make sure the computer your own ability to read / write data with greater speed when using solid-state drives.

Here is some information you should write to your hard drive as well as solid advice if you are going to upgrade to SSD. 

Life

The technology used in SSDs provide very high security, especially in the control chip. Chip control is an integrated microprocessor, controls the communication between flash memory and the server (usually PC ). There are many SSD manufacturers while some companies only produce controller chip count on the fingers, as the SandForce SF-2281 chip used on the Kingston HyperX 3K, SanDisk Extreme, Intel Series 335; longer lines and Vector SSD OCZ Vertex 4 controller, use the Indilinx is genuine; Corsair, the first choice for LM87800 chip from Link A Media company, while the Samsung SSD 840 Pro also uses "the map" as MDX.

 

The enterprise SSDs typically use NAND type SLC (single-level-cell, a memory cell levels), while for SSD users typically use NAND MLC (multi-level). The difference between the two types of NAND memory is the number of bits stored per memory cell (cell). A level that is going to have 1 bit of data, while MLC is 2 bit of data that is stored on one memory cell. There is a further NAND FLASH TLC ( triple-level cell) but they do not appear on products sold for the mass market. 

The more bits are stored in each cell, as the SSD is larger, and the price is also cheaper because the manufacturer can provide multiple silicon die per wafer than help them reduce production costs . However, in exchange for the stability of the MLC NAND SSDs use SLC NAND is not as high as their Rewritable cycle is reduced. 

According to calculations, an SSD will have an average lifespan of 10 to 20 years even more. The flash memory cell wear when you write data to them. In a certain sense, this is like writing on a piece of paper with a pencil and erased. For example, Vertex 3 120 GB SSD drive can be recorded rate of 3,000 cycles. If you write to drive 50GB per day, the total number of days drive can be used before it loses credibility is: (120 x 3,000) / 50 = 7200 days, that is about 20 years. If you burn each day on average 100GB drive will be used for about 10 years. 

Technology on SSD longevity

SSD technology used to sort the data distribution are called wear-leveling (balance depreciation) to ensure that all write data to memory cells in the drive, on a record before any memory cell.Thus, memory cells do not have too much while recording a memory cell to receive a little almost.In addition, the SSD also uses a number of algorithms temporary transfer less data changes (such as operating system files) in many areas was recorded, to record the use of the data less frequently changes.

 

In addition, to enhance the life of solid state drive, all the NAND chips will have more memory than the standard regulations about 4%. The redundant backup is used to replace the damaged and worn out. That's why some SSDs the storage capacity of 240 GB or 120 GB, but the actual use may be 128 or 256 GB. Many manufacturers provide to increase the lifespan of the NAND drive.

Higher capacity, better performance

The hard disk drive HDD rotation speed in minutes (often abbreviated as rpm) fixed. This is the main indicator to measure drive performance side caching. Slower rotation speed, hard drive takes much more time than retrieving data. Hard drive rotation speed 7,200 rpm or 11,000 rpm ensures faster working speed with RPM hard drive 5400 rpm. This is a quantitative figure is easily recognizable to consider when we choose to buy HDD.

 

But with SSDs, through actual test, p PCWorld has concluded that a drive with a larger capacity will be faster than a smaller capacity drives (on a controller chip and NAND chip as each). So why the capacity to affect the performance of an SSD?

With mechanical hard drives HDD, basically write data to a sequential disk blade and very little interruption. Meanwhile, SSDs write data to multiple NAND at the same time. Drive more NAND chips, the faster the write speed.

SSD hard drive can not optimize speed by software

Currently, newer motherboards usually support Sata III interface with up to 6Gbps bandwidth, the use of this standard SSD can achieve read speeds, recording more than 550MB/giay. Experiment with the fastest SSD can record at speeds close to 5 Gbps.

 

The fact that you can not further optimize the speed of SSDs using the utility software. The optimization techniques developed for mechanical hard drives do not apply for SSD. Wasting write cycle to try to optimize SSDs are jobs counterproductive.

Increased efficiency through TRIM commands

After a period of use, the performance of the SSD will gradually decline. That is because the NAND flash memory can not be overwritten. That means that if you want to write to a cell that already contains data, the first controller chip to erase recorded data in that cell. When recording new data, the controller chip erase also want to delete the data, called the course "Data collected discarded" (garbage collection).

TRIM command (this is not an acronym for a phrase), which allows an operating system like Windows 7 support, proactively notifies the SSD which data blocks that are no longer considered to be used and can deleted from the inside. This helps drive more efficient operations and result in faster performance. Often the TRIM command will automatically be enabled by default.

Tips to buy SSD

As mentioned in the first article, SSD owns many advantages compared to HDD. But the price is expensive, a small obstacle when the user wants to access the SSD. However, if you intend to drive this kind of property, you should also note some drawbacks of a low-capacity SSD, recognition error rate remained relatively high and broken. SSD may be "dead" if dropped or firmware updates.

 

Thus, when intending to purchase an SSD you should note:

- Buy drives have the largest storage capacity on your financial situation. You will get better performance, proportional to size.

- Select the drive strength and speed stability. SSD is basically 3 main categories:

+ Uses NAND Type Single Layer Cell (SLC) is not so high speed, but very durable, Rewritable 100,000.

+ Type NAND using Multi Layer Cell (MLC) with high speed but strength is up to 10 times less than SLC (cycle P / E is only 10,000 times the maximum). Due to the cheaper MLC SSD is the most common type today.

+ Type NAND using Triple Layer Cell (TLC). This type of high speed, but the most unstable, only Rewritable up to 1000 times, ie less than the SLC hundred times. Products for Samsung SLC now has 840, but not many people preferred.

- If you are running an operating system that does not support TRIM, check for updates from the manufacturer.

- Use an SSD to run the OS and application software. The archive film, music and other data to put on the hard drive to minimize mechanical HDD erase write cycle.