Fragmentation over time and Auto-TRIM
Upon completion of our test suite, we run multiple write passes to each drive to evaluate the impact of the random writes that took place. Most SSDs will perform poorly after undergoing such stress. Samsung and Indilinx are both constantly working to improve their performance over time, but they have both taken different paths to reach their respective goals.Samsung
Samsung has implemented a feature they call “auto-TRIM”, which peeks at the NTFS $bitmap to clear up unallocated areas during idle time. The advantage is these drives will recover performance given sufficient idle time, and will do so on any platform. The catch is it only works with NTFS partitions, meaning Mac and Linux users will not share the benefit seen by Windows users. Here was the OCZ Summit after running our suite:
I then refragmented it and let it sit idle for a few hours time:
The Summit was able to bring its write speed back up with no user interaction, mostly recovering by the time we ran our test. Another hour or so and it would have restored itself entirely. This means typical users should see full speed writes most of the time. Note that Samsung units self-defragment on-the-fly during sequential writes, meaning write speed returns to normal after a single sequential pass has taken place.
The big catch with Samsung is the lack of end-user flashable firmware, as no tool has been released to accomplish this task. This means some older models with the same controller might not see the benefits of auto-TRIM. That said, all currently shipping Corsair and OCZ units are equipped with this feature. I’ve heard Samsung plans to release a native TRIM enabled firmware for these units in conjunction with the release of Windows 7, but at the moment this is just a rumor.
The big catch with Samsung is the lack of end-user flashable firmware, as no tool has been released to accomplish this task. This means some older models with the same controller might not see the benefits of auto-TRIM. That said, all currently shipping Corsair and OCZ units are equipped with this feature. I’ve heard Samsung plans to release a native TRIM enabled firmware for these units in conjunction with the release of Windows 7, but at the moment this is just a rumor.
Indilinx
Indilinx has taken a different approach to fighting fragmentation, first coming out with their own special tool and proprietary implementation of TRIM (again limited to Windows). More recently they have released firmware with native TRIM support. This feature is not just limited to Windows, it only applies to the yet-to-be-released Windows 7 (as well as future OS versions for Mac and Linux). At present the only native-TRIM firmware available is from SuperTalent and OCZ (see below). Until all Indilinx distributors push out the new firmware and everyone moves to a TRIM enabled OS, most users are likely to see this:
Indilinx has taken a different approach to fighting fragmentation, first coming out with their own special tool and proprietary implementation of TRIM (again limited to Windows). More recently they have released firmware with native TRIM support. This feature is not just limited to Windows, it only applies to the yet-to-be-released Windows 7 (as well as future OS versions for Mac and Linux). At present the only native-TRIM firmware available is from SuperTalent and OCZ (see below). Until all Indilinx distributors push out the new firmware and everyone moves to a TRIM enabled OS, most users are likely to see this:
All is not lost, as OCZ has been cooking up their own custom firmware with background Garbage Collection. This effectively defragments the blocks in the background, restoring sequential write speeds without the need to rely on TRIM. The newest OCZ firmwares are based on the newest Indilinx firmware 1711, which includes native TRIM support, meaning that once OCZ works out all the bugs, their users can have the best of both worlds. More on OCZ’s firmware efforts can be seen in our previous coverage of one of their beta firmwares.
