bit-tech.net

Why You Need TRIM For Your SSD

SSD Apocalypse

For current SSD users, our performance figures might come as a bit of a shock, but they really do demonstrate just how extensive performance degradation can become across all three of the so called “big three” SSD drive controllers under heavy loads.

Following our 1TB of varied file size writes to the three drives running with non-trim firmware, all three were affected by huge performance drops, although interestingly the high level of write/rewrite cycles affects each drive differently.

Corsair P128 128GB 18C1Q / Samsung ARM

The P128’s sequential read speed is largely unaffected by the heavy write/rewrite load, with speeds measured by AS SSD dropping by just 15.2MB/s to 210.9MB/s. Write speeds don’t weather so well though and are cut by a whopping 53 per cent to just 82.71MB/s. Both read and write access times also suffer, with a read access time of 0.094ms rising to 0.3ms – that might not appear to be much, but when your drive performs so many read commands, especially at startup, it adds up, adding an extra two seconds to the Windows 7 boot time.

It’s random write speeds where there’s real cause for concern though, with the P128 in its heavily used condition recording just 1.11MB/s random write speed alongside write latencies that peaked at a whopping 1410ms. This is the sort of performance degradation you’ll notice in just everyday use, with the drive hanging waiting to perform a write. ATTO performance further demonstrates this, with a 4KB write speed of just 23MB/s in comparison to the 66MB/s of a new drive – a 65 per cent drop, although it’s worth noting that 64KB and 1MB writes in ATTO were largely unaffected by our heavy loading.

Intel X25-M 160GB Gen2 / Intel

The Intel drive is hit by far the hardest of the three drives by our heavy write/rewrite load, losing much of its sequential read and write speed. Sequential read as measured in AS SSD has dropped by 51 percent to 127MB/s and write speeds fell an amazing 72 per cent to just 22.92MB/s – that’s slower than a decent USB flash drive. Access times also rocketed with read access times especially affected, rising from 0.06ms to 0.946ms – a fifteen fold increase. Why You Need TRIM For Your SSD SSD Apocalypse

While the Intel drive’s superb random read speeds are left unaffected, random write speeds drop by 82 percent to 7.06MB/s, although this is still far superior to the Samsung powered P128 at its stock performance.

ATTO performance corresponds to much of the other data, with 1MB writes at just 23MB/s and 4KB reads at just 142MB/s, although this appears the poor read performance isn’t uniform across file sizes – 64KB and 1MB file read speeds suffer little to no performance dip.

OCZ Vertex 120GB v1.3 / Indilnx Barefoot

The Vertex is hit hard when it comes to its sequential read speed in AS SSD, plummeting to a poor 133.27MB/s – a drop of 42 per cent. Its write speed is oddly only reduced by 20MB/s though, although the end result is still slower than a Spinpoint F3 on both accounts. While random read speed is unaffected, random write speed is cut in half, with maximum write latencies climbing to 139ms from a clean drive max latency of just 10ms.

ATTO sequential reads and writes back up the results from AS SSD, with 64KB and 1MB read speeds slashed by 46 per cent and 47 per cent respectively. The reduction is read speed also has a minor effect on Windows 7 boot times, with the system taking an extra second to start up from a warm boot.

These results should be enough to demonstrate just how important the TRIM command is to a modern SSD. Without it (and remember, all these firmware versions were in use by customers, and likely still are if you’ve not updated), all three drives were utterly unable to maintain performance to an acceptable level and saw obvious and noticeable performance degradation in a variety of different ways between them.