The essence of computer has changed a lot during the last decade, but not all bottlenecks have been removed from it. One of such bottlenecks is a hard drive. Its because of it that operating system often cannot boot from a cold start for 10 seconds. There is SSD, but using it as main storage is difficult due to small capacity. So it means that SSD cannot crack the modern architecture: there is slow storage and fast random-access memory. Random-access memory is fast and yet it is volatile. Hard drive is secure, non-volatile, but slow. In its turn, SSD is both faster than hard drive and non-volatile. In future, SSD (or its successor) is simply obliged to replace both random-access memory and hard drive. As of now one can essentially speed up computer with the help of SSD. SSD is not a rarity any more and can be frequently seen inhome computers. Users often create a system volume on it, install OS andheavy software(they say that even Photoshop runs like crazy on it) and keep on storing music and movies onhard drives.Inservers, whenfast databasework is required, you can order SSD as carrier and after doing that databases becomelive. Until there is no space left on SSD. Then users order cunningRAID arraysor collect clusters.In 2011 Intel company presented to those in need for speed a technology calledSmart Response Technology(SRT), that uses SSD as caching buffer between RAM andhard drive. You can use SSD with capacity up to 64Gb, and not the files are being cached, but accessedlogical blocksfrom hard drive and if SSD is suddenly filled up, then cells that have not been accessed for a long time period will start filling in withnew data. This SRT works likeLinuxworks withRAM. So now everything is clear with reading. In case of writing things are far more interesting and there aretwo usage modes: fastest possible and expanded. In expanded mode the data is written simultaneously to both SSD andhard drive. This mode is slower than the former but is reliable and guarantees that data will be saved on hard drive whatever happens. Naturally, data is saved to SSD at the next accessing, system receives themvery fast. In optimized forspeed modedata is first saved to SSD and then tohard drivewith a certain delay, whenever it is convenient (called ‘lazy writing’). In this mode the speed of saving data is only limited by thewriting speedto SSD, but data integrity is not guaranteed — there is a chance of power supply failure during the writing process (which is not relevant for laptops) or, all of a sudden, SSD crashes, in this case part of data that was not written to hard drive will be lost. The behaviour of this mode reminds me of Redis: fast, smart and secure enough, but has to be used very carefully.Caching is realized viaRAID array, in which you need to add hard drive and SSD in BIOS and you need to clearly specify SSD as acaching device. Such option is in BIOS on motherboards with chip setZ68.You need only to turn on caching in BIOS and then immediately forget how to access this scary place. Intel makes products for people and that is why caching is set in the system itself with the help of simplegraphic tool: If in the work process SSD suddenly fails, then if there were no writes in fast mode, the user won’t notice anything: SSD will fall off and everything will start working very slow, you will have a feeling of shifting from LAN to dial-up. But using only SSD read/write speed would be a blasphemy, second huge bonus is hidden in non-volatility. It means that after rebooting data will remain in cache and if you frequently run Photoshop then it will start slow only for the first time and all other times it will start fast, even after rebooting.
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