I created an excel spreadsheet that auto-calculates whether your raid array is properly aligned. It also auto-calculates non-raid
partitions. You must meet the requirements of all Rules to be considered Aligned
You must input your own data. It will not fetch your system information automatically. That's why the example column is there.
Let me know of any corrections or additions I can make to the sheet.
Partition alignment is the single most important performance tweak you can do for any SSD.
Lets break it down to it's simplist form. The SSD is divided into Blocks of 512k which are divided into pages of 4k in most cases. 128 pages = 1 block.
There is a certain amount of space before the start of the first partition, which is what is referred to as the offset. Vista and W7 use a default offset of 1024k, meaning there's 1024k of empty space before the partition. Starting at 1024k means that the partition starts at the beginning of the third block, since blocks are 512k (512k x 2 = 1024k).
The goal is to not start a partition in the middle of a block or a page. That way, you don't split any boundaries. If you split a page (4k) section, then 2 writes are necessary to write the page instead of 1, doubling the work. It will happen repeatively every 8th page, reducing overall performance and I/O commands. Blocks have a similar performance hit but not to the same degree as pages. It's easy to align to both.
Alignment has to be done when the partition is created. There are tools such as a gparted boot CD that can change alignment after it's created, but it's not 100%. Sometimes, you can lose your data with that method. It's best to fresh install and correctly create the partition at the beginning. Windows Vista/7 will both correctly align a partition. You must not have any previous partitions on the SSD and allow Windows to create and quick format the partition during the installation procedure.
WinXP is another story because it will not align a partition correctly by default. Extra steps are involved. The easiest way to align a WinXP OS volume is to get the downloadable Vista Recovery DVD and create the OS partition before the installation of WinXP. The partition created by the Vista Recovery DVD will be the same as the Vista Installation DVD and will be aligned at 1024kb by default which is a valid alignment for todays hardware.
It takes a moment to wrap your head around the new technology, but the sooner you forget HDDs, sectors, tracks, and cylinders, the better off you'll be. It's all about the blocks and pages now.
Online SSD Alignment Calculator
written by TechPowerUp!'s W1zzard.
VBScript Alignment Checking Tool
originally written by TcpDump's Tom Hirt. Discovered by Halk and edited by me to work with all SSDs with 512kb block sizes.
SSD Alignment Spreadsheet
created by me.