Windows 7 for SSD optimization common problems detailed

When Microsoft developed Windows Vista, the SSD has not been so hot, so it has not been optimized accordingly. Windows 7 is different. Microsoft has put SSDs at a critical position from the very beginning. Recently, the corresponding optimization measures for the new system have been elaborated through the official blog. The soft media is organized as follows.

First, SSD performance degradation and Trim request operation

Flash block (Block), Page (Page) and Cell (Cell) must be erased before writing new data, so The newly purchased SSDs performed very well, but they felt a decline in performance over a long period of time, after Intel tried to solve the problem by upgrading the firmware.

Microsoft said that they have observed this phenomenon, but it is not as serious as everyone thinks. In fact, apart from the benchmark test, the user basically does not feel different in daily operations.

Storage Products

Of course, vendors are still obligated to maximize performance. The hardware manufacturer first completely erases the SSD before it leaves the factory (similar to the low-level formatting of the hard disk), and the second is to prepare a special space for dense burst writes. The enterprise hard drive will even reserve up to 50% for this purpose. Space to maintain a high sustained write speed for a long time.

Microsoft also uses a "Trim" mechanism in conjunction with SSD vendors. In Windows 7, if the SSD report supports the Trim attribute in the ATA Protocol Data Set Management (DSM) command, the NTFS file system will ask the ATA driver to issue a new Trim operation command to the SSD when the user deletes the file, telling it to be relevant. The page can be safely erased. After the SSD gets this indication, it will not rush to perform the erase operation, but wait for the right opportunity, that is, when there is a write operation again, because the relevant page can be reused at this time, there is no need to perform the wipe. Except for the operation.

Comparison of write speed after switching Trim

For example, if a 128KB block contains a 128KB file, if the file is deleted and By performing the Trim operation, the SSD can avoid mixing the bytes in this block with the other bytes needed for subsequent writes to this block, which can greatly reduce the "wear" of the SSD.

In Windows 7, Trim requests are not limited to delete operations, but are fully integrated with partition and volume level commands, file system commands, and system restore functions.

Second, Windows 7 optimization and default behavior brief

On SSD, Windows 7 will disable disk defragmentation, because the SSD random read operation mechanism is very good, defragmenting files No more help. Windows 7 also disables SuperFetch, ReadyBoost, and boot and program prefetch by default on SSDs, which are designed for traditional hard drives. The partition creation tool built into Windows 7 also takes into account the characteristics of solid state drives. Of course, it's best to put the system partition on a solid state drive.

III. Frequently Asked Questions

1. Will Windows 7 support Trim?

Support. See above.

2. Will defragmentation be disabled by default on SSDs?

Windows 7 defragmentation will exclude SSD partitions, and if the hard disk partition random read performance exceeds 8MB/s, defragmentation will ignore it. The 8MB/s metric is internally analyzed by Microsoft and will be added to the final version of the system. In fact, this rule is of little significance, because the SSDs are generally 11-130MB/s, and the 182 traditional hard disks tested only have more than 2MB/s, and all others are at 0.8-1.6MB/s.

3. Will SuperFetch be disabled on SSDs?

Yes, but not absolute. Microsoft originally intended to disable SuperFetch on SSDs, but it experienced a large performance degradation on some systems. Later, it was discovered that the random write and erase operations of the first-generation SSDs were too frequent, which eventually led to a very high read speed. Slow, and when SuperFetch and other prefetching technologies are turned on, performance is clearly picking up.

4. Will NTFS compress folders and files on SSDs?

Compressed files help free up free space, but compression and decompression require additional CPU resources. It will consume more power, so it is only suitable for files that are not commonly used, but it is not necessary for files and folders that are frequently read and written, such as my documents, such as temporary Internet folders.

5, Windows search index will be different in the SSD?

No.

6. Is BitLocker optimized for SSDs?

Yes, on NTFS file systems. BitLocker reads, encrypts, and writes to the entire partition, and the NTFS file system uses the Trim command to help the SSD optimize this operation.

7. Will the media center configuration be different on SSDs?

No. Media recording and playback are mostly continuous operations, and the unit capacity of SSDs is now much more expensive than traditional hard drives, so storage and backup are still the preferred mechanical hard drives.

8, write cache makes sense for SSD? If SSD supports write cache, what is the corresponding action of Windows 7?

Some SSDs except flash memory chip, main controller It will also add a certain amount of RAM as a cache, which is mimicking the traditional hard disk to cache writes. For such devices, the erase and write commands in Windows 7 are expected to remain at the same level as traditional hard drives.

9. Does RAID make sense for SSDs?

Yes. SSD RAID can achieve the same performance and reliability as mechanical hard disk RAID.

10. Should the page file (virtual memory) be placed on a solid state drive?

Yes. Most page file (Pagefile.sys) operations are very small random reads or large continuous writes, which is where SSDs are best at. After thousands of traces of page file read and write, Microsoft found that the read/write ratio of page files is 40:1, 67% of reads are less than 4KB, 88% is less than 16KB, and 62% of writes are not. It is less than 128KB, and 45% is exactly 1MB. In short, there is no better place to put on a solid state drive than a page file (virtual memory).

11. Is it good to put a hibernation file on a solid state drive?

No. Hiberfile.sys is a large block of read and write, so it is the same on a mechanical or solid state drive.

12, Windows experience index will be adjusted according to SSD performance?

Windows 7 has added some new random read, random write and erase evaluation. A good SSD score will be above 6.5, with a maximum score of 7.9, and an abnormal rating of 1.9 points, 2.9 points during the test period will not appear again. Of course, if the performance of the SSD itself is average, the score in Windows 7 will be similar to that under Windows Vista, and it will not rise.