谈谈固态硬盘（SSD）及其在Windows 7的优化

参见 http://dencode.blogspot.com

SSD是英文Solid State Drive的缩写，中文译作固态硬盘或电子硬盘，目前越来越多地在计算机和便携电子设备中使用。SSD是基于电子芯片，通常用闪存(Flash)芯片。闪存芯片细分也有很多类，如NAND, NOR, MovieNand, iNand, eMMC。大家常用的SD卡就是Nand闪存芯片封装在塑料壳内。

SSD有众多下显而易见的优点，可以替代传统硬盘，只是价格上还不具优势。其优点是：具有低功耗、无噪音、抗震动、低热量的特点，不仅使得数据能更加安全地得到保存，而且也延长了靠电池供电的便携设备的连续运转时间。例如韩国三星半导体公司（SAMSUNG Semiconductor）于2006年3月推出的容量为32GB的固态硬盘，采用了和常规微硬盘相同的1.8英寸规格。其耗电量只有常规硬盘的5%，写入速度是常规硬盘的1.5倍，读取速度是常规硬盘的3倍，并且没有任何噪音。对于玩电脑游戏，或运行大量计算，或经常编译大量程序的用户来说，目前的计算机CPU速度都很快，内存也足够多，显卡的性能也不错，通常瓶颈就在硬盘上。我经常用GNU的compiler编译大量程序，我的Laptop换了SSD后，其编译速度不亚于Core i7的Desktop PC。
目前SSD的最大问题仍然是成本和写入次数。随着SSD逐渐普及，工艺不断改进，芯片的集成度不断提高，其成本正逐步下降。而闪存的写入次数通常在1万到一百万次，对普通用户来说，SSD的寿命足以使用到更新换代的时刻到来。相比之下，其售价的下降还很缓慢。
SSD大部分被制作成与常规硬盘相同的外形，例如常见的1.8英寸、2.5英寸或3.5英寸规格，并采用了相互兼容的接口；但有些固态硬碟也使用 PCI Express 或是 Express Card接口，以提高传输的速度或减小体积。
由于SSD具有与传统硬盘显著不同的特性，所以在Windows操作系统中，有很多设置可更好地发挥SSD的优越性。下文译自 Computing.net by Tom's Guide，原文Solid State Drive (SSD) Tweaks for Windows 7。

中文翻译参见 http://dencode.blogspot.com

This HowTo is to provide the common tweaks used to optimize your new SSD for Windows 7. I would recommend checking the performance of your SSD before and after these tweaks to see how they impact your performance. I recommend using AS SSD Benchmark to check your performance.

Warning! The reader takes full responsibiity for any damage that may occur to their PC or hardware by follwing these recommended tweaks. These are just recommendations to improve the performance of the SSD but are not required if your SSD is functioning correctly.

Step 1. SATA Controller set to AHCI Mode:

• During the installation process, you want to ensure your BIOS are set to AHCI for the SATA controller to enable AHCI. AHCI is needed for native TRIM support utilized by a SSD.
• If you have already installed the OS in IDE mode, it is recommened to switch to AHCI after completing the steps listed in this Windows Article: http://support.microsoft.com/kb/922976, if your BIOS support AHCI.

Step 2. Verify TRIM is Enabled

Verifing TRIM will confirm that the TRIM commands are being sent from Windows to the SSD.

How to Verify TRIM is Enabled

•  
  • In the start menu search box, type" cmd";
  • Right click the cmd program and select Run as Adminstrator; and
  • In the command line type "fsutil behavior query DisableDeleteNotify".
    • if DisableDeleteNotify = 0 TRIM is Enabled.
    • If DisableDeleteNotify = 1 TRIM is Disabled.

When typing in the command window, don't include " " when typing.

 

Step 3. Disable System Restore

System Restore on a SSD can degrade the SSD performance over time and make it very difficult for TRIM to work. It is recommended to disable System Restore to prevent this and to regain valuable SSD storage sapce.

How to Disable:

•  
  • Right click on My Computer and select Properties;
  • Select System Protection;
  • Select Configure; and
  • Select Turn Off System Restore.

 

Step 4. Disable Drive Indexing

With the access times of a SSD (0.1 ms for most), there is no need to index the drive for quicker response times, like with a standard hard drive.

How to Disable:

•  
  • Go into My Computer;
  • Right click your SSD and select Properties; and
  • Un-check the box marked "Allow files to have contents indexed in addition to file properties".
  • A popup screen may appear, stating there is an error applying attributes, this is normal and you should select "Ignore All" and continue.

 

Step 5. Disable Drive Defragmentation Schedule

By default, Windows 7 should automatically disable defrag by default as part of the TRIM requirements. In case it doesn't, you'll want to disable this feature, as defraging your SSD is not a good thing!!

How to Disable:

•  
  • Go into My Computer;
  • Right click your SSD and select Tools tab;
  • Select the box Defragment Now;
  • Select the box Configure Schedule; and
  • Un-check the the Run on a Schedule Box.

 

 

Step 6. Disable PageFile

This does not improve the performance of the SSD but does get you back 3 to 4 GB of valuable space on your SSD. Also, it is not recommend for users with less than 4GB of Memory or doing without watching your RAM usages prior to implementing.

How to Disable:

•  
  • Right click My Computer;
  • Select Properties;
  • Select Advanced System Settings;
  • Select the Performance tab and Advanced tab;
  • Select the Change box for virtural memory;
  • Un-check Automatically Manage Page File Size For All Drives;
  • Select No Paging File and click the set box; and
  •  Select Yes to allow and restart.

 

Step 7. Disable Hibernation

Disabling hibernation will return 2 GB of valuable storage space to your SSD. Also, it provides no real benefit to a SSD due to it's quick load times.

How to Disable:

•  
  • In the start menu search box, type" cmd";
  • Right click the cmd program and select Run as Adminstrator; and
  • In the command line type "powercfg -h off".
  • Once completed, the command prompt returns.

When typing in the command window, don't include " " when typing.

 

Step 8. Disable Prefetch and Superfetch

How to Disable:

•  
  • Type Regedit into the Start Menu;

 

•  
  • Select the file path; "HKEY_LOCAL_MACHINE\CurrentControlSet\Control\SessionManager\Memory Management\PrefetchParameters"
  • Right click on both EnablePrefetcher and EnableSuperfetch;
  • Select modify on each of these to change the value from 1 (or 3) to 0, and
  • Restart.

 

Step 9. Disable Windows Write-Cache Buffer Flusing

This is not recommended for Intel SSD, as it has a negative effect on their performance. It is recommend to check performance before and after this tweak to determine if has a negative or postive effect.

How to Disable:

•  
  • Right click My Computer and select Properties;
  • Select Device Manager;
  • Select Disk Drives;
  • Right click the SSD and select Properties; and
  • Under the Polices tab, uncheck the Enable write caching on the device.

 

Step 10. Disable Windows Search and Superfetch

How to Disable:

•  
  • Press Winkey + 'R' for Run Dialogue;
  • Type "services.msc" and press Enter;
  • Scroll to Superfetch, right click and select Properties;
  • In the drop down menu, select Disabled and select Ok;
  • Scroll to Windows Search, right click and select Properties;
  • Click the Stop box, than use the drop down menu, select Disable and select Ok.

 

Step 11. Disable ClearPageFileAtShutdown and LargeSystemCache.

How to Disable:

 

•  
  • Type Regedit into the Start Menu;

 

•  
  • Select the file path; "HKEY_LOCAL_MACHINE\CurrentControlSet\Control\SessionManager\Memory Management"
  • Right click on both ClearPageFileAtShutdown and LargeSystemCache;
  • Select modify on each of these to change the value from 1 to 0, and
  • Restart.

 

Step 12. Adjusting the Power Settings

Adjusting the Power Settings

•  
  • Go to Control Panel;
  • Select System and Security'
  • Select Power Options and Click the drop down for Show Additional Plans;
  • Select the High Performance bubble to apply it;
  • Click Change Plan Settings for High Performance;
  • Click Change Advanced Power Settings;
  • Click the hard disk drop down option;
  • Change Turn off hard disk after to 0 minutes (Never)
  • Select OK; and
  • Select Save Settings.