Optimising your SSD in WindowsThere are numerous guides on the Internet offering to help you to optimise your SSD in Windows. The first thing to do, which has nothing to do with the OS however nor even with SSDs, as it also applies to standard hard drives, is to activate the AHCI mode in the Serial ATA controller instead of the standard IDE mode, which isn’t necessarily the default setting. AHCI mode allows the storage peripheral to optimise processing during multiple simultaneous accesses. Note, it’s preferable to make this change before installing your OS as otherwise you'll get a blue screen when you start your computer up again, though Microsoft does offer a "Fix It" for Windows Vista or 7 which allows you to move to AHCI without having to reinstall.
In terms of Windows 7 optimisations, we have to keep in mind that Windows was designed with native SSD support and there’s therefore no need to carry out the slightest performance optimisation at the level of the OS itself.
Behind the optimisation advice claims lie a total under-playing of the robustness of current SSDs, which have been designed to handle a minimum of 20 to 40 GB of writes per day for five years, which is much more than the 5 to 10 GB that you’d expect from standard use. There’s therefore little point in trying to minimise writes and it can even be counter productive for the overall speed of the system if you move certain temporary files to a hard drive. Equally, indexing your searches is less of an advantage on SSDs than HDDs, though indexing your searches will make them faster than standard searches on SSDs.
This isn’t however the case in Windows Vista where you will need to turn automatic defragmentation off as this is counter-productive on SSDs (the OS isn't aware of the internal organisation of data on the flash). Nor does Vista support the TRIM command in real time, unlike 7: with Vista therefore it’s best to go for SSDs with software that allows you to run TRIM regularly on the free space on the drive, as with the Intel Toolbox and Samsung SSD Magician.
If you’re using Windows XP you’ll also have to create the partitions manually (or with another more recent OS) with SSD-friendly alignment: the basic alignement creates the first partition as of the 63rd sector of a storage device (namely at 32.5 KB), which falls between two flash pages on an SSD. A single 4 KB write would then fall between two 4 KB pages on the SSD and it would therefore have to write both these pages. Windows Vista and 7 leave a margin of 2048 sectors, which helps the SSD to avoid unnecessary wear and poor performance.
Max OS X and Linux
What about other operating systems? Apple’s Mac OS X supports SSDs correctly but TRIM support, which has been included since version 10.6.8, doesn’t work unless the SSD is from Apple. Trim Enabler
however provides a get-around for this. Linux has supported TRIM since version 2.6.33 of the kernel in ext4, but to turn TRIM support on you have to make the partitions with the discard option.
Increasing available capacity in Windows
While Windows 7 doesn’t need to be optimised in terms of performance, it can however be modified to free up space on your SSD if you’re using it as your system disk. Two features can in effect take up a relatively significant amount of disk space with respect to the still fairly reduced size of SSDs:
- Virtual memory
Hibernation reserves space on the disk according to the size of your RAM via the hiberfil.sys file and disabling it saves you the space taken up by this heavy file at the root of the SSD system. This does however mean that you can no longer use the ‘Suspend To Disk’ type standby.
To delete hiberfil.sys, you have to execute the powercfg -h off command
The virtual memory is a memory zone on the system disk that can be used like the RAM if the RAM isn’t available in large enough quantities. Of course, if you do have to use it, virtual memory is much slower than the RAM but it’s availability does mean applications don't crash simply due to lack of memory. Once again here, Windows automatically reserves the equivalent of your RAM on the SSD via the pagefile.sys, and it’s possible to reduce the amount of space reserved.
To reduce pagefile.sys you have to customise the size of the Pagefile by going into advanced system settings then
clicking the settings button and the advanced tab and then the modify button for the virtual memory (phew!).
It’s impossible to give a magic formula however (in spite of what many people may say), as everything depends on how you use your PC. If you reduce your Pagefile too much and a software needs more memory than the system can offer, it will crash. Given the low cost of memory however, PCs are generally overprovisioned in RAM compared to their real requirements.
With a general usage level of 4 GB of RAM, you shouldn’t need much more than 2 GB of swap and with 8 GB, 1 GB should cover most Pagefile needs.
On a 64 GB SSD with 16 GB of RAM – which it is true, represents an extreme case – prolonged standby and the Pagefile take up 28 GB of space by default!