為什麼XP安裝碟分區會留下8MB未使用??

[psac]

Q:
120G的硬碟用PQ分完區後怎麼算來算去少20個G？
在2000下顯示：C：6.3、D：30.2、E：30.2、F：30.2、G：14.6G。加一起也不夠120G啊，就是廠商和系統的算法不一樣，也不應差這麼多吧。
另外一棵5400RPM的SAMSUNG SV1604N，電腦上BIOS顯示是160G硬碟，WIN2K FORMAT以後只有128G了。
由於換算問題，硬碟實際可使用容量比標稱小5％左右是正常事

A:
哈!老兄算術的有點問題
聽我道來...............
只少了9G而已，很正常
完全正常!
下算法例:
120,000,000,000 Bytes/ 1024 /1024 /1024 = 111.76 GBytes
，還有你沒有開啟48位LBA訪問，所以只能看到128G
160G硬碟偶記得是有個137G的限制的,和BIOS的LBA尋址有關係~~但是你這個既然BIOS都認,那可能是win2K的那個尋址方式要開啟

這沒什麼問題的,處理方法你可選擇:
1.昇級主機板的BIOS為支持大於127GB以上HD的最新版
2.下載一個WIN2000下的修正檔(到MS或HD廠商網頁上搜尋驅動)

再說明...沒什麼可怕的，簡單的說就是：
XP --> SP1, 你看 ms的說明
hxxp://support.microsoft.com/default.aspx?scid=kb;en-us;303013
WIN2K --> SP4, 再看此文 hxxp://support.microsoft.com/default.aspx?scid=kb;en-us;303098

也就是..............注冊檔修改一下!!
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Atapi\Parameters\EnableBigLba
設成DWORD, 值為1。
如果BIOS能看到160G，那麼XP可以不用昇級SP1，直接設定註冊表。

其他系統預設驅動無法支持>128G(137G)硬碟。

還有另外一種方法是安裝Intel的IAA驅動。其他晶片組可能也有類似IAA等支持48bit LBA的驅動。

http://support.microsoft.com/defaul...kb;en-us;305098
The following conditions are necessary for the correct functioning of 48-bit LBA ATAPI support:
A computer with a 48-bit LBA-compatible Basic Input/Output System (BIOS) installed.
A computer with a hard disk that has a capacity of greater than 137 gigabytes (GB).
You must enable the support in the Windows registry by adding or changing the EnableBigLba registry value to 1 in the following registry subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\atapi\Parameters

To enable 48-bit LBA large-disk support in the registry:
Start Registry Editor (Regedt32.exe).
Locate and then click the following key in the registry:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Atapi\Parameters

On the Edit menu, click Add Value, and then add the following registry value:
Value name: EnableBigLba
Data type: REG_DWORD
Value data: 0x1

Quit Registry Editor.

NOTE: If you enable 48-bit LBA ATAPI support by editing the preceding registry key, but your system does not meet the minimum requirements, you may observe the following behaviors:
Operating systems that do not have 48-bit LBA support enabled by default (such as Microsoft Windows 98, Microsoft Windows Millennium Edition (Me), or Windows 2000) that are installed on a partition that spans beyond the 28-bit LBA boundary (137GB) will experience data corruption or data loss.
The installation of operating systems that do not have 48-bit LBA support enabled by default (such as Windows 98, Windows Me, or Windows 2000) on a partition that is beyond the 28-bit LBA boundary (137 GB) is unsuccessful and leaves behind a temporary installation folder.
If you install hotfixes that enable 48-bit LBA before you install Windows 2000 Service Pack 3 (SP3), the appropriate registry key will be automatically created during the installation of SP3 to preserve the data integrity of the hard disk.
After you enable 48-bit LBA support by adding the appropriate registry key, data corruption may occur if you remove the registry key or if you remove (uninstall) SP3 for Windows 2000.
If you install a copy of Windows 2000 that includes SP3 (SP3 integrated) on a large hard disk that has already been preformatted by using a 48-bit LBA-enabled operating system, the ATAPI subsystem may report hard-disk space greater than that which is addressable without the 48-bit LBA support (larger than approximately 137 GB) during the text-mode portion of Setup. In this case, the hard disk's partition table information has already been created. To fix the incorrect disk information, delete the partition by using either a disk partitioning utility or by deleting and then re-creating the partition during the text-mode portion of Setup. After you create the new partition, quit Setup by pressing F3, and then restart the Windows installation process. The ATAPI subsystem now correctly shows approximately 137 GB of hard disk space.
The EnableBigLba registry value is disabled:

If you have a 48-bit compatible BIOS that can support a hard disk that has a capacity of more than 137 GB, only the first 137 GB of the hard disk is addressable. The remainder of the hard disk is not used.
The operating system must be installed on the first partition that is smaller or equal to 137 GB when the EnableBigLba registry value is enabled but when you do not have a 48-bit LBA compatible BIOS.

If you enable the 48-bit LBA ATAPI support by editing the registry setting, but you lack both a 48-bit LBA compatible BIOS and a hard disk that has a capacity of more than 137 GB, the hard disk continues to function as a standard hard disk with an addressable limit of 137 GB.
The operating system must be installed on the first partition that is less than or equal to 137 GB and the rest of the hard disk divided into one or more remaining partitions when the EnableBigLba registry value is enabled on a computer without a 48-bit LBA compatible BIOS that has a hard disk with a capacity of more than 137 GB.
STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Windows 2000 Service Pack 3.Important Although support for 48-bit LBA is included in Windows 2000 Service Pack 3 (SP3) and later, it is still necessary to create the registry change that is described in the "Resolution" section of this article.

好了!總結：
容量的差異主要是由於使用不同的進製造成的。
我們普通的算法是1K=1024，所以1M=1KK=1000*1000=1000,000
而電腦上面的數學進制是1K=2^10=1024，所以1M=1KK=1024*1024=1048576
當計量服務機構到G後，就會產生更大的差異了。

有硬碟容量「減少」的朋友該知道是怎麼回事了吧。




Q:
那麼XP安裝碟分區為何,總會留下8Mb的未使用???? 莫宰羊
8Mb並不重要,主要想知道是什麼原因??
我用PQ把它分給了最後分區,WINDOWS居然說發現新硬體,要求重啟動.
主要想知道是什麼原因??
或許是個老問題.別笑我!

A:
備用 ...
給"移動硬碟 "
這8MB用來存放硬碟、分區等參數的。
這就預留了各種操作系統、從C到Z的所有分區的信息空間。

原來如此！我也想過為什麼要给硬碟扣下這8MB，當然是有一定的用途，現在我懂了！

多謝多謝您的教學！

原來怎麼回事....我明白了....多謝指教

[hwj_c]

多謝

原來如此..謝謝囉.

這是真的嗎? 我曾用PQ去給它加大分區把那8MB用掉，也沒有發生任何問題啊。 而且把資料放在沒有畫分的區域是非常容易流失的吧!?