Windows 7 drives the adoption of solid state drives

When Microsoft developed Windows Vista, the SSD was not so hot, so it was not optimized accordingly. Windows 7 is different. Microsoft has put SSDs at a critical position from the beginning. Recently, the E7 official blog has elaborated on the corresponding optimization measures of the new system.

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.

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 Related pages 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.

For example, if a 128KB file contains a 128KB file, if the file is deleted and the Trim operation is performed, the SSD can avoid the bytes in this block. The other bytes required for subsequent writes to the block are mixed, which greatly reduces the "wear and tear" 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. These features are designed for traditional hard drives.

Windows 7's built-in partition creation tool also takes into account the characteristics of SSDs. 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 SSD?

Yes. 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, eventually leading to The read speed became extremely slow, and with SuperFetch and other prefetching technologies turned on, performance improved significantly.

4. Will NTFS compress folders and files on SSDs?

Compressed files help free up free space, but compression and decompression require extra CPU resources and power consumption in notebooks, so it's only suitable for less common files, but for frequent It is not necessary to read and write files and folders, 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 the NTFS file system. 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. Does writing cache make sense for SSDs? If SSDs support write caching, what are the corresponding steps for Windows 7?

Some solid-state drives, in addition to flash chips, the main controller, 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, RAID makes sense for solid state drives?

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

10. Should the page file 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 tracking of page file reads and writes, Microsoft found that the read/write ratio of page files is 40:1, 67% of reads are less than 4KB, and 88% are less than 16KB. 62% of writes are no less than 128KB, and 45% are exactly 1MB.

In short, there is no better place to put on a solid state drive than a page file.

11, will the hibernation file be placed on the SSD?

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

12. What is the Windows Experience Index based on SSD performance?

Windows 7 includes some new random read, random write and erase evaluations. 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.