||Why the packaging labeled capacity 120GB SSD, but the actual use less than 120GB?
Both HDD and SSD vendors use the term GB to represent a decimal GB or 1,000,000,000 (10^9) bytes. Flash memory (like other electronic storage) is assembled in powers of two, so calculating the physical capacity of an SSD would be based on 1,073,741,824 (230) per binary GB. The difference between these two values is 7.37% (=(230-109)/109 × 100%).And controller will reserve space, to act as a buffer to improve data safety.
actual capacity≒packaging labeled capacity x0.93
||Is SataIII compatible downward with SataII or SataI?
SATAIII's official name is SATA 6Gb / s, bandwidth converted to speed is 600 Mb / s
SATAII's official name is SATA 3Gb / s, bandwidth converted to speed is 300 Mb / s
SATAI's official name is SATA 1.5Gb/s, bandwidth converted to speed is 150 Mb / s
The specification of SATAIII provides the function of downward compatibility for SATA I and SATAII interface
However,the different specifications of every specification's like SSD supports 6Gb / s specification,
when connecting to 3Gb / s interface,the maximum speed of SSD will be reduced.
||Why computers can not detect SSD?
1.SSD uninitialized partition:Open the Disk Management to check if the SSD is not initialize;if instruct”uninitialized”,please partition format after initialize it,then you can use.
2.Enter BIOS to see if it detect the SSD, if can not be detected, please check or replace power- supplied SATA cable and data cable for connections.
3.The abnormal External voltage or power outage cause component damage.
We recommend you to contact with our QA dept(telephone: 035987298#4168), to analyze problem.
||Effect of AHCI on performance
The Advanced Host Controller Interface (AHCI) is a technical standard defined by Intel; it allows Serial ATA (SATA) storage devices to communicate with the software to let Serial ATA (SATA) storage devices to start the advanced SATA function, for example Native Command Queuing (NCQ) and Hot plugging.
Native Command Queuing (NCQ) is a function of AHCI; it can let ATA drives to accept many instructions and re-arrange instructions, to reach maximum efficiency.
If use NCQ with hard disk drives which supports NCQ,it can improve the storage efficiency of random workloads.
Enter BIOS to find Integrated Peripherals-->OnChip Serial ATA Device, check if it is the AHCI option;
it means if your chipset support NCQ function, if need to use the NCQ function, should set the SATA Mode of BIOS as AHCI.
||Why SSD needs 4k aligned?
The smallest writing unit of NAND FLASH is “Page”, and the general size of each page is 4KB. In the era of traditional hard drive and Windows XP, the starting point is sector 63 (it is the position of 31.5KB);it is not the integer multiples of 4K,so writing data in each page will be written across to second page, to affect performance and life.
||How to align 4k partition?
It all can align 4k automatically by using built-in formatting function of disk management
on windows 7 or later version Operating system; or you can download 4k alignment tool like Paragon Alignment Tool.
||How to confirm 4k alignment and ahci function
You can use AS SSD Benchmark software to check. After opening the software, you can see a window on the top of left side , which displays hard disk information, there are two statuses: BAD and OK. The first row shows the mode of hard disk IDE & AHCI ; the second row shows 4K aligned. (see red frame below )
AHCI is not enabled and unaligned 4K
Windows 7 adds a TRIM function to support specifically for SSD; the main reason is “Block”, “Page” and “Cell” have to erase block first then record new data. As no more pre-erase block, writing with time and reduced space capacity accumulates to cause the efficacy of burst write reduce. The function of TRIM is to indicate the block/cell data which SSD can delete document block/cell as “invalid”: allow erasing build-in memory beforehand, when there is write activity, should execute erasing operation.
If want to use TRIM function, there are two conditions have to be met at the same time:
1. The operating system (e.g.Win7, Win8, Windows Server 2008 R2 Linux(kernel 2.6.33 or later editions) has to support TRIM command.
2. The device driver and SSD have to support TRIM function as well.
Check Trim function.
To check the TRIM function default on Windows 7:
1.Executing cmd command character by system administrator
Click Start button → Click All Programs → Accessories → Command Prompt
Execute instruction: fsutil behavior query DisableDeleteNotify
There are two possible situations
1.DisableDeleteNotify = 0: TRIM function is already enabled and working in Windows.
2.DisableDeleteNotify = 1: If TRIM function is disenabled, → Key in “fsutil behavior set disabledeletenotify 0” in command prompt and press “enter”, then it can be enabled.