How to pick a solid state drive

How to pick a solid state drive?

Open a large electric dealer website SSD Solid State hard disk Display page, currently can see 40 different brands. This may confuse many people, how can there be so many brands? To know, the mechanical hard disk market after the brutal competition baptism, currently left several famous brands: Seagate, Western Data (west), Toshiba, Hitachi, which Hitachi has also been acquired by the West. Mechanical hard disk manufacturing technology is very complex, harsh conditions, can make competitive products of the company, just a few. SSD solid-state drive is different, it is still in vigorous development, far from reach mature stage. Its main original is the main control and flash memory chip. The main chip is similar to CPU, a number of companies in the provision of products, each with characteristics, different performance, mutual competition, flash memory chips are similar.

This is more like the characteristics of mobile phone products: industrial chain upstream to provide chips and originals, downstream with different chips, the original combination, to make high school low different grades, different characteristics of the products, control the quality of the product.

It is precisely because of this, the purchase of SSD will encounter with the purchase of mechanical hard disk different problems: shoddy, fake. Mechanical hard disk is similar to the CPU, it is difficult to fake, because there is no technology, want to counterfeit can not counterfeit. But SSD is not the same, some unscrupulous manufacturers, can completely use inferior storage chip to make the price "very attractive" products, even counterfeit brand, people fooled. When a person discovers a problem, it cheats or plays missing.

Therefore, the procurement of solid-state hard drives, the preferred formal business, the preferred formal brand, have after-sale guarantee. This seems to have become a "cliché", because buy what product, this word can be set up. But as long as it is true, it's OK to say it again. A penny a penny, hard drive price, data priceless. If you find a brand, product prices, much lower than the market average, you have to be very careful, suggest to retrieve its evaluation information, especially outside the electrical business site evaluation. Because the product page evaluation may be a single brush forgery.

If you fancy a product, in addition to check the user evaluation, you can also find users to disassemble the text. There are a lot of solid-state hard disk products on the Internet to disassemble the article, you can see the solid state hard disk use of the main control chip model, Flash chip type ~ (details back to mention). This can not be done for mechanical hard drives, mechanical hard disk dismantling requires strict dust-free environment, or dismantling means scrap.

By browsing through the product list, you will find that even the same volume of solid-state hard disk products, the price gap is very large. The reason for the gap, in addition to the brand pricing strategy, there are two reasons: the use of the main control chip (SSD CPU) different, memory chip grade difference. At present, the mainstream products in the market, the main control chip suppliers, the common is Intel, Marvell, SandForce, Samsung and JMicron, Phison and so on. Different company's product, the characteristic is different, the performance and the price difference is many. Some inexpensive SSD, basically use a few price comparatively inexpensive of the Taiwan series product, performance is fair, still more superior than mechanical hard disk. Medium and high-end products, most of the use of Marvell/sandforce chips. Samsung can design and manufacture the main control chip and memory chip at the same time, the product is unique. Intel's products are expensive, but the overall quality is superb, it is the first choice for enterprise applications.

These performance gaps can be reflected in SSD test scores, with different product ratings being 40% to 50%. But in the daily use, the more value of random reading and writing indicators. Because SSD's own performance bottleneck, it is 4K random read and write ability. The so-called 4K, refers to the hard disk default storage unit size, which will also be mentioned later. The meaning of this parameter is more important, because the daily use of random Read and write small files most, it is directly associated with the use of experience. Although many solid-state drives claim that their products can be read and written to more than 450-550 megabytes, they reach the upper limit of the interface standard. But this is a continuous read-write operation, not most of the operating state.

Another thing to consider is the flash chip. It can be said that SSD solid-state hard disk performance characteristics mainly determined by the main control, and reliability, durability by the flash chip decision, its selection is crucial. A good brand will often indicate in the product introduction page, what memory chip is used in this product, what features

The current flash technology is divided into 3 major categories: SLC/MLC/TLC here to cite a little explanation: SLC is a single layer, one unit stores 1 bit. MLC is a double layer, one unit stores 2 bit, TLC is three layers, and one unit stores 3 bit. The more layers, the shorter the life, the poorer the performance, the cheaper the price.

SLC read-write speed, high reliability, long life, can achieve 100,000 times to erase, is MLC more than 20 times times. MLC can be erased 3000-5000 times.

And TLC is much worse, generally can only write to 500-1000 times, as for performance, price, poor also a lot. TLC flash memory for a large number of cheap u disk products, SLC solid-state hard disk is rarely seen, this is the price reason: too expensive. Note that as the flash process progresses, the number of times to erase is declining. Why? Storage density increased, the "storage pool" thinning, not resistant to rub.

It can be said that a large number of SSD solid-state drives are used MLC type of flash storage, is based on the balance of performance, life, Price choice, is also reasonable. However, even the MLC type of flash memory, the quality is very different. The industry on the flash memory chip has the so-called original, white, black piece of the argument. After the production of a wafer, there are many small wafers, the scientific name die. After encapsulation is a particle, after cutting, the first screening test, that the qualified and reliable individual classification out of the retention, will continue to test later. If the test does not pass, it will not be easily discarded, will be sent to a special factory for recovery treatment. The factory will try to carry out further testing and classification.

To some products to reduce frequency, shielding memory units, divided into many grades. If the quality grade is lower, the price will be sold. The original test clearance, and later found defective chips, will also fall into the category of poor quality to reduce sales. This is the source of a large number of white films. The white piece is not marked, which is handled by the user. But the quality has the obvious flaw, the reliability extremely bad that kind, becomes the black piece-this is when the garbage disposal, originally should not use. White, black film in fact can be regarded as the manufacturing process of defective, but still have a grade difference. If SSD uses white piece, the quality is already at risk. Even famous OCZ have burst into the white gate incident. If the unfortunate purchase of black products, the results are conceivable, please pray a lot, from the blessing of it. Interested people, you can search the wafer manufacturing process video to understand the inside.

Photo above: Wafer test

In addition, flash particles are differentiated by working mode, and there are synchronous and asynchronous differences. The synchronous type of flash drives more frequently, performs better, has more than a single asynchronous type of bandwidth, and is more expensive and, of course, higher in manufacturing quality.

If the use of a good flash chip, manufacturers are not stingy with the layout to promote this selling point. Products on the page, will tell you, with a certain brand of the original flash memory, such as the type of MLC particles. But in fact, no manufacturer will say that their products used "white", "black film", often vague say: The original MLC, high-speed MLC. It is often not done. This is the moment when you have to be careful. The chip may be of a general quality, I'm sorry to say.

If you want to buy, suggest to look for this model product disassembly text. This is what it says about the meaning of evaluation and dismantling. Buy black solid hard disk, waste money is small, if give your data cause loss, often is irreparable, also is far from that point hard drive price can change back. In addition, some small brands because there is no competitive advantage, and sometimes the use of good products in the early stage, the later part of the despicable trick. This kind of product is too easy to cheat. This is also the purchase of such products, the priority to choose a big brand, brand significance. The price is expensive, but buy it at ease. Brand-name products rarely do Shino things.

Above: A cheap SSD found black film after dismantling

High-quality SSD products, the internal will also add 128MB-512MB high-performance cache, further improve performance. But prices will also be higher, and cheap SSDs tend to shrink in this area.

Here we can't help mentioning a product, Samsung's EVO series. Samsung is the flagship of solid-state hard disk industry, the strength of the company. Starting with the 840 model, Samsung has used TLC chips, rather than MLC chips, on the EVO series. This includes the 840 evo/850 EVO, while the Pro series does not use a TLC flash. Please note that Samsung did not mark this on the product page. But according to Samsung's own version, its 3bit MLC ~ (another name for TLC, Good point) to erase 1200 times, than ordinary TLC products. There have been written tests on the web, whose product life, although shorter than MLC products, can still reach official standards. But it is doubtful that it is a TLC product but sold the price of MLC, is it the main control bonus points?

In recent years, the price of solid-state drives has slipped along with the technological advances and the scale advantages brought about by the increase in production. Last year the mainstream market or 128G capacity of products, this year has run to 256G capacity products. Solid-state drives are affordable, buy big and don't buy small. For technical reasons, large-capacity SSD will be written faster and will live longer. Can be expected, if the mainstream capacity of solid-state hard disk can reach more than 512G, the price is only slightly higher than the mainstream mechanical hard disk part of the market, even if the capacity of the mechanical hard disk may be several times, the mass choice of host, solid-state hard disk configuration ratio will also be greatly improved. Because this capacity is enough to meet the needs of many general applications, compared to the speed of the increase, a few times the capacity, the attractiveness will also decline. This is not good news for traditional hard disk manufacturers.

Say so much, sum up the main point: To view the main control manufacturer and chip technology characteristics, the preferred original, large manufacturers synchronous MLC Flash, preferably the famous brand, to the big electric business place to buy, refused to counterfeit goods.

Some friends will ask, I want to make a solid-state hard drive taste, improve the performance of the host, but my computer is a few years ago, the motherboard only support to SATA2.0, install interface for SATA3.0 Solid state hard disk can? SATA3.0 backward-compatible SATA2.0, 1.0. The first thing to be clear is that for everyday applications, the most common hard drive action is random read and write, rather than large data sequential reading and writing, unless you have nothing to do with a country action film on the hard drive back and forth. SATA3.0 's theoretical interface rate is one STAT2.0, 6.0gb/s, which is the bit value, which translates into an easy-to-understand unit, divided by 10, which is 600mb/s. At present, the mainstream solid-state hard disk reading performance has been able to close to this limit, but look at the test results above the graph, random read and write performance is still far away. Don't say SATA2, it is in the SATA1 motherboard with solid state, application start-up speed will also improve a lot. Only in the 1 generation above, feeling a bit overqualified. You can completely buy a new solid state drive, and when your host is Yinianbanzai and upgraded, the hard drive can continue to be retained. In addition, the International Standards Organization has developed updated interface standards, the future SSD solid-state drives, performance will continue to improve.

Below is the SSD performance test diagram on the SATA2.0 interface, and the performance is passable.

Solid-state hard disk size is relatively small, most of them are 2.5-inch 7mm ultra-thin style. Notebook can plug and Play, desktop use will need to use the 2.5-3.5 of the switch, this is not difficult, it is easy to solve. In addition to the common SATA interfaces, there are other types of interfaces. For example, part of SSD is mSATA interface, suitable for some notebook use. In addition to the interface and use of different occasions, the other things are generally consistent. Not here to say more.

To buy SSD, the first task is basically to replace the existing mechanical hard drive. Because most people now want to use SSD as a system disk. But don't be busy, there are a few things to do:

1, to the BIOS inside to see if the hard drive interface to open AHCI, can not use IDE mode. This setting is critical and performance-related. AHCI mode, which supports NCQ (Native command queue), which improves hard disk performance and some power features. If your motherboard doesn't support this option, it's too old. Throw it away and upgrade the motherboard. Otherwise, using SSDs is too wasteful.

According to existing tests, whether to open AHCI mode, SSD performance gap can reach 50%-60% or more, the loss is extremely alarming.

2, the motherboard also has energy-saving options: c1e, C3/C6, eist, etc., if opened, SSD will lose a certain performance, but not big. If you want to pursue the ultimate performance, you can turn off the energy saving option.

3, view the motherboard on the SATA hard disk interface type. Some motherboards, because of the limitations of the chipset, provide only 2 SATA3 type of native hard disk interface, there is no doubt to receive the interface above, to the other place, into the SATA2 will spin down.

4, the operating system version must be more than Windows 7, can not use Windows XP-Lianpo old! Because only Win7 is built to support a feature that is important to SSDs: trim directives. The trim directive is also called disable deletion notification (Disable delete notify), and technical details are not described here, which is that it effectively improves the read-write efficiency of solid-state drives and improves service life by reducing writing. The default is open. At present, the SSD on the market basically supports trim instruction.

If your original system is XP, then quickly back up the data, install upgrade to Windows 7 bar. Using Windows XP on SSDs is a serious waste. If the original system is already more than Win7, then consider the problem of migration.

Some solid-state hard disk manufacturers, they have provided a number of "cloning" software to help you carry out the migration work, please check the usage instructions. With its support, migrations are often simple. Without this type of software, you can also use Ghost Dafa or similar tools to copy an entire hard disk or boot partition to a new hard drive. Copying an entire hard disk can sometimes involve capacity issues: SSD capacity is small and it is impossible to clone all of the content. Direct clone partition? Win7 above operating system, in the installation will default to generate a 100MB-200MB about the system to preserve the partition, to save the startup information. If you copy the Windows installation partition directly to the new hard drive, you will find that you cannot start the operating system at all. Because the information for that partition is gone. Ghost can back up more than 2 partitions at the same time, but cannot recover at the same time.

This provides a scenario that may not be the best approach, but has been tested repeatedly and is actually available. First ghost the Windows 7/8 installation partition of the original hard disk to the file, remove the original hard drive, replace it with a new solid-state drive, use the WINDOWS7/8 installation disk, and install the new hard drive again; Use the original ghost mirrored file that was backed up by the first step, Revert to the newly installed Windows partition, and do not touch the small system to reserve the partition and reboot. If you find a better software or a simpler way to transfer, you are welcome to share it with you and avoid a relapse.

Reinstalling Windows 7 also has an additional benefit: partition automatic 4K alignment. This problem will make a mistake if you are not careful. Currently, partitions are automatically aligned to the hard disk in versions above Windows 7. This is the problem with the lower version of the operating system, which is the result of the NTFS version, and the old version of NTFS is not aligned by default. 4K alignment is defined as the location of the integer reading and writing, which means that the higher performance of Read and write speed, less writing, longer life, is very important. No 4K alignment, every read and write to cross sector operation, solid state hard disk life will rapidly decline, the performance is also very wide gap.

How to detect? Very simply, use software to view.

Above: 4 K is aligned, AHCI is turned on

SSD life problem, in the previous article has been discussed, the normal use of the situation, no need to worry, it can ensure the daily use of this computer life is over. But beware, do not defragment, SSD is needed "fragmentation" because to balance write. As a result, Windows 7 defaults directly to the defragmentation of the SSD, and the normal switch does not pull the power off. At present, there are tests show that SSDs may be in the case of accidental power outages, the deadlock, failure.

Also, pay attention to the manufacturer of the product you purchased, and whether you have released a new version of the hard drive firmware. HDD firmware is the software that manipulates the master, and its upgrade optimization will bring great benefits to your solid-state drive.

Solid state hard disk purchase, use of the common knowledge of the finished. Finally, I wish you all to buy a satisfactory product, eliminate computer performance bottlenecks, enjoy the general speed of operation, really cool up.

Solid-state hard disk Purchase summary: here simply recommend a few brands, originally to avoid suspicion, do not want to write, but incredibly someone said I give a power to a weak text. This association ability really lets a person admire. Pound, recommend several products:

Pukot-High quality SSD, one of the industry benchmarks;

Samsung Pro Series-King style, do not recommend the EVO series;

Flash di SanDisk-flash industry giants;

Creative-flash good, main control 4K performance is strong, mainly price concessions;

Pirate Ship-very good, just too expensive point;

Intel-Ace products, too expensive.