Intel 335, TRIM not available, zeroing beneficial?

[JPete11]

Hi, I have an Intel 335 240GB SATA drive installed behind a PATA bridge (old Thinkpad X41). I'm running Linux 2.6.32 (and 2.6.34 is also an option that works with this hardware -- later kernels don't seem to be able to set up the framebuffer how I want it). It appears that TRIM is not available over the PATA bridge.

Assuming TRIM is not available, is it better to live without TRIM (and leave plenty of unused space on the drive), or attempt to emulate TRIM by zeroing unused blocks. Zeroing might be beneficial if the drive optimises storage of zero blocks. Otherwise it will just add more wear.

Does anyone know if zero block storage is optimised on this drive and will work as a TRIM substitute?

[Jose_H_Intel1]

Hello,

It is possible that TRIM is not enabled due to the SATA/RAID controller (PATA bridge) you are using.

In case this is true, you may secure erase or low level format the drive whenever you observe performance degradation, with the major consequence of deleting all files from the drive, unless you have a SATA controller that identifies the drive properly and provides the TRIM command to it.

[JPete11]

Yes, it appears that TRIM is not available over the PATA bridge that I have (maybe in combination with my kernel version). Should I imply from your reply that zeroing unused blocks is not beneficial? You imply it in your answer but do not state it. Thanks.

[Jose_H_Intel1]

A secure erase or low level format will be beneficial against the performance degradation caused by the lack of TRIM.

[idata]

Do NOT write zeros or anything to a SSD in an attempt to clean it as TRIM does.That will not benefit anything and only cause more performance degradation.

Any time anything is written to NAND storage cells, it is then in the used/written to state. Before it can be written to again, the NAND cells must be cleared/reset to their "ready to be written to" state. That is what slows down performance, the time it takes to prepare enough NAND cells that are not reset before they can be used. TRIM commands tell the SSD which data is no longer needed, and the SSD can then reset those NAND cells when it is not busy.

When you mentioned "... optimises storage of zero blocks.", that sounds like a data compression like feature, created for HDDs? The SandForce controller in a 335 does data compression of its own, but I would not expect a SSD to perform anything designed for HDDs.