dedicated hardware/software combination), followed by an analysis
with an evidence discovery tool.
Whether or not you’ll be able
to access deleted information
stored on an SSD drive depends
on the system using the SSD drive
supporting the full TRIM/garbage
Operating System Support
TRIM is a property of the operating system as much
as it is a property of an SSD device. Older file systems
do not support TRIM. Wikipedia http://en.wikipedia.
org/wiki/Trim_(computing) has a comprehensive table
detailing the operating system support for the TRIM
command. Put simply, TRIM support was only added
in Windows version 7 and later. In addition, Windows
only supports TRIM if the drive is formatted with the
NTFS file system. If the SSD drive carries a different
file system such as FAT32 or exFAT, there will be no
TRIM on that drive.
In Mac OS X, TRIM is only supported for SSD
drives approved and supplied by Apple, and only
starting with OS version 10. 6. 8. Notably, user-installed SSD drives not supplied by Apple itself are
excluded from TRIM support.
Old or Basic SSD Hardware
Not all SSD drives support TRIM and/or background garbage collection. Older SSD drives as well
as SSD-like flash media used in basic tablets and
sub-notebooks (such as certain models of ASUS
Eee) do not support the TRIM command. For example, Intel started manufacturing TRIM-enabled
SSD drives with drive lithography of 34nm (G2);
their 50nm SSDs do not have TRIM support.
In reality, few SSD drives without TRIM survived that long. Many entry-level sub-notebooks
use flash-based storage often mislabeled as “SSD”
that does not feature garbage collection or support
the TRIM protocol.
External Drives, USB Enclosures, and NAS
The TRIM command is fully supported over the
SATA interface, including the eSATA extension,
as well as SCSI via the UNMAP command. If an
SSD drive is used in a USB enclosure or installed in
certain types of NAS storage, the TRIM command
will not be communicated via the unsupported
PCI-Express and PCIe SSDs
Interestingly, the TRIM command is not natively
supported by any version of Windows for many
high-performance SSD drives occupying the PCI
Express slot. Do not confuse PCI Express SSDs with
SATA drives carrying M. 2 or mSATA interfaces.
PCI Express boards implementing an SATA port
are also excluded from this exclusion.
The TRIM command is not supported on most
RAID configurations (with rare exceptions). SSD
drives working as part of a RAID array can be
A notable exception to this rule would be the
modern RAID 0 setup using a compatible chipset
(such as Intel H67, Z77, Z87, H87, Z68) accompanied by the correct drivers (the latest Rapid Storage
Technology driver from Intel allegedly works) and
a recent version of BIOS. In these configurations,
TRIM can be enabled.
Surprisingly, SSD drives with corrupted system areas
(damaged partition tables, skewed file systems, etc.)
are easier to recover than healthy ones. The TRIM
command is not issued over corrupted areas because
files are not properly deleted. They simply become
invisible or inaccessible to the operating system. Many
commercially available data recovery tools (e.g., Intel
Solid-State Drive Toolbox with Intel SSD Optimizer,
OCZ SSD Toolbox) can reliably extract information
from logically corrupted SSD drives.
Bugs in SSD Firmware
Firmware used in SSD drives may contain bugs,
often affecting the TRIM functionality and/or
messing up garbage collection. For example, OCZ
Agility 3 120 GB shipped with buggy firmware v.
2.09, in which TRIM did not work. Firmware v.
2.15 fixed the TRIM problem, while v. 2. 22 introduced issues with data loss on wake-up after sleep.
Firmware v. 2. 25 fixed that but disrupted TRIM operation again ( http://www.overclock.net/t/1330730/