Why is the capacity of the hard drive purchased is smaller than the actual size? You should have encountered such a situation. Why is the actual storage only a little more than 3t when you obviously bought a 4t hard drive. We add hard disks mainly to increase storage space. Is the problem of reduced storage capacity due to hard disk quality? The hard disk is one of the main storage media of a computer, consisting of one or more aluminum or glass discs. The disc is covered with ferromagnetic material. Hard disks include solid state drives (SSD disks, new hard drives), mechanical hard drives (HDD traditional hard drives), and hybrid hard drives (HHD, a new hard drive based on traditional mechanical hard drives). SSD uses flash memory particles for storage, HDD uses magnetic disks for storage, and hybrid hard disk (HHD: Hybrid Hard Disk) is a hard disk that integrates magnetic hard disk and flash memory. Most hard drives are fixed hard drives, which are permanently sealed and fixed in the hard drive. Hard disk capacity involves conversion between decimal and binary arithmetic. Among them, hard disk manufacturers use decimal arithmetic in order to facilitate calculations, while computers use binary arithmetic, and conversion calculations are required between them. Hard disk manufacturer decimal calculation: 3000GB=3000,000MB=3000,000,000KB=3000,000,000,000Byte Operating system binary calculation: 3000GB=3072,000MB=3,145,728,000KB=3,221,225,472,000Byte 1GB actual byte (Byte) calculation: 1GB=1024MB*1024KB*1024Byte=1,073,741,824Byte Then the actual capacity of 3000GB: 3000,000,000,000Byte/(1024MB*1024KB*1024Byte)=2793.97GB Why the actual capacity of the 3TB hard disk is 2794.39GB? That is because the hard disk manufacturer will have 0.1-1GB more capacity left in the actual production, so it is slightly larger than the actual capacity of 2793.97GB. So when 2794.39GB is converted to TB, after deducting the partition occupies 177MB, the remaining capacity is divided by 1024GB. After rounding up, the actual capacity is equal to 2.72TB. This is the origin of the 2.72TB capacity. The price of 3TB hard drives is cheap, and merchants naturally don’t worry about not selling them, but historical experience has repeatedly told merchants that 3TB hard drives are not unsellable, but after being sold, customers return the goods and replace them with 2TB hard drives + the price difference. Could it be that the price of the 3TB hard drive has dropped, and the quality has followed? Of course not, the quality of hard drives is inherited. Perhaps most netizens cannot think of this reason-hard disk partitioning. Merchants revealed that the most feedback from customers is the partition problem. The latest report shows that WinXP users account for 42% and Win7 users account for 44%. It is precisely that WinXP cannot fully recognize the capacity of a 3TB hard drive; Win7/8, which supports 3TB hard drives, also has the characteristic that the operation process is not simple. Reasons for capacity limitation: The motherboard BIOS 2 years ago defined 512 bytes per sector for MBR partitions, and the disk addresses 32-bit addresses. The maximum disk capacity that can be accessed is 2.19TB (232*512byte). Windows starts from the MBR, so each MBR is limited to 2.19TB. The remaining 746GB of the 3TB hard drive is recognized as the second hard drive. Break the capacity limit: Since the era of Vista and Win7, in order to solve the problem of hard disk limitation, the GPT format has been added. GPT means GUID Partition Tables (GUID Partition Tables), and GUID means Globally Unique Identifier. The full name of GPT is the globally uniquely identified partition table. The GPT partition table uses 8 bytes or 64 bits to store the number of sectors, so it can support up to 264 sectors. Similarly, based on the 512byte capacity per sector, the maximum capacity of each partition can reach 9.4ZB (that is, 9.4 billion TB). GPT broke the 2.19TB limit of MBR. The main performance indicators of the hard disk According to the main performance indicators of the hard disk, the quality of a hard disk can be measured. Therefore, it is necessary to understand the main performance indicators of the hard disk. ①Capacity The capacity of a hard disk is the most important technical indicator to measure a hard disk, and it is the parameter that users are most concerned about when buying. The capacity of the hard disk is determined by the number of disk faces (the number of heads), the number of cylinders and the number of sectors. The calculation formula is: hard disk capacity = number of disk faces × number of cylinders × number of sectors × 512B. There are often multiple stacked disks inside the hard disk. Therefore, the hard disk capacity can also be calculated as follows: hard disk capacity = single disk capacity x number of disks. The single disk capacity of a hard disk has a certain impact on the performance of the hard disk. The larger the single disk capacity, the higher the density of the hard disk, and the more information the head can read in the same time. Therefore, when the total capacity of the hard disk is the same, the hard disk with fewer discs should be selected first. Many users are often confused by the size of the hard disk capacity. Why is the nominal capacity different from the actual size displayed on the computer? This is mainly due to non-standard and non-uniform conversion units. At present, there are 1MB=1024KB to nominal, and some 1MB=1000KB, so the capacity is inconsistent. ② Speed Rotation Speed ​​has a direct impact on the data transfer rate of the hard disk. Rotation speed is one of the decisive factors of the internal transfer rate of the hard disk, and it is also an important sign to distinguish the grade of the hard disk. In theory, the faster the speed, the better, because a higher speed can shorten the average seek time and actual read/write time of the hard disk, thereby increasing the read/write speed on the hard disk. But everything has two sides. As the speed increases, the heat generation of the hard disk will increase, and its stability will be reduced to a certain extent. Nowadays, the speed of mainstream hard disks is mostly 5400rpm (revolutions per minute), 7200rpm and 10000rpm. 7200rpm hard drives have become mainstream. ③ Cache Cache is the place where the hard disk exchanges data with the external bus. To put it simply, the larger the cache capacity on the hard disk, the better. Large-capacity cache is good for improving the speed of the hard disk. Currently, the hard disk cache capacity on the market is usually 2MB to 8MB. ④ Average seek time Average Seek Time refers to the time it takes for the hard disk head to move to the track where the data is located, in milliseconds (ms). The shorter the average seek time, the faster the hard disk speed. The average seek time is generally between 5ms and 13ms, and hard drives larger than 10ms are not suitable for purchase. ⑤ Data transfer rate of hard disk The data transfer rate of the hard disk (Data Transfer Rate), also known as the throughput rate, represents the speed at which the hard disk reads or writes data after the head is positioned. ⑥ Continuous trouble-free time Continuous failure time (Mean Time Between Failure, MTBF) refers to the longest time from the start of the hard disk operation to the failure of the hard disk, the unit is hours. The MTBF of a general hard disk is at least 30,000 hours or 40,000 hours. This indicator is not provided in general product advertisements or common technical feature tables. If necessary, you can go to the website of the company that produces the hard drive. Housed in compact packages with profiles as low as 0.95 mm, our range of electret condenser microphones and MEMS microphones offers a variety of performance options to meet the voice capture and audio recording needs of your next design. Our microphones are available with omnidirectional, unidirectional, and Noise Cancelling directivity, while featuring sensitivity ratings from -54 up to -24 dB and signal to noise ratios from 56 up to 72 dBA. Mic Wireless,Wireless Microphone,Bluetooth Microphone,Condenser Microphone NINGBO SANCO ELECTRONICS CO., LTD. , https://www.sancobuzzer.com