【 Weak current College 】 hard drive internal data transfer rate

Internal data transfer rate (InternalTransferRate) refers to the hard disk head and cache data rates between, simply put the hard disk data to be read from the disc, and then stored in the cache. Internal transfer rates can be clearly demonstrated the hard drive's read/write speed, its high and low is the evaluation of a hard drive a decisive factor for the overall performance, it is the true measure hard drive performance. Effectively increase the hard disk's internal transfer rates to the disk subsystem performance has the most direct and obvious. Currently all hard drive manufacturers strive to improve the hard disk's internal transfer rate, in addition to improved signal processing technology, improve the speed, the most important is to constantly improve the single disc capacity to enhance linear density. Because single-disc capacity, the greater the higher the linear density of hard disks, magnetic head seek distance can frequency and corresponding reduction, reducing the average seek time, internal transfer rate also increased. Although the hard drive technology development quickly, but internal data transfer rate is still in a relatively low (relative) level, internal data transfer rate low has become the largest hard disk performance bottlenecks. Current mainstream consumer hard drives, internal data transfer rate basic still at 70 ~ 90MB/s or so, but in continuous operation, this data will fall lower.

Data rate units generally use MB/s or Mbit/s, especially in the internal data transfer rate on official data in more use Mbit/s. Here it is necessary to explain the two units, the difference between them:

MB/s mean megabytes per second, Mbit/s means megabits per second, the former refers to the number of bytes transmitted per second, which refers to the number per second transmission bit digits. MB/s b in the meaning of the letters is Byte, although Mbit/s and the bit in the translation, is a bit, it is a measure of data, but they are completely different. Byte is the number of bytes, bits, bit is in the computer each octet is a byte, that is, is 8bit 1Byte = 1: 8. Therefore 1MB/s is equal to 8Mbit/s. So when writing unit must note B whether letters are uppercase or lowercase, in particular, some people still get short Mbit/s to MB/s, where B-letter size really can be called missing mile, absurd to Trinidad.

This is normally MB/s and corresponding Mbit/s, but in hard drive data rates, they will not be able to use General MB and the conversion of Mbit (1B = 8bit) for conversion. For example, a product of official nominal internal data transfer rate to 683Mbit/s, cannot simply be considered 683 divided by 8, it considers 85MB 85.375/s is the hard disk's internal data transfer rate. Because 683Mbit also contains many bit (bit) of auxiliary information, incomplete data transmitted is a hard drive, a simple conversion for 8 years, will not be able to get real value for internal data transfer rate.