Five months ago we published a review of the SanDisk Extreme 240GB SSD. This drive, the first of its kind in more ways than we knew at the time, started a long and frustrating experience. The Extreme was the first product to cross our desk with new SanDisk 24nm Toggle Mode Flash. At that time, it was easy to point to the flash and say that any problem discovered had to do with the new exotic flash. What we didn't know at the time was the Extreme also brought with it our first look at Series 5 firmware from LSI SandForce.
The firmware system in place works roughly like this. The base code is produced by SandForce and that is where the revision number comes from. Before February 28th, drives coming in used what we call Series 3 (3.3.2, 3.3.4 and so on). The base code goes to manufacturers where it is key coded and customizations are added. In the customizations, features that produce Max IOPS, CapX 'Host Power Loss Protection' capability, throttle rate and other differentiating points are added. At that point the manufacturers release the code to the public. If there is a problem with the underlying base code, it affects everyone who builds on top of it. We see the same thing with motherboards, video cards and other products as well - if Intel's foundation code is off, then the problem is found on all motherboards using that underlying code.
In our testing the SanDisk Extreme 240GB was very fast, faster than any other SandForce based drive we've ever seen before"¦ at first. The problem started to show up as we worked our way through the benchmarks. After a standard run we went back and re-tested the drive without a secure erase cycle and the performance dropped like a brick. These were the very same tests we'd just run a couple of hours before and achieved record setting scores. For the next month we worked our way through all of the typical issues that could pop up. System stability, drivers and so forth were all tested out of the equation. By that time I had six test systems running in the lab 24/7 and a whole fleet of SanDisk Extreme drives.
During all of this, other new drives hit the office and they all tested normal, all with 3.3.2 and 3.3.4 based firmware. It wasn't until the Biwin Elite arrived that we started making sense of the problem. Biwin uses standard firmware numbering and this drive arrived labeled as 5.0.1. At that point we were able to match the performance profile of the SanDisk Extreme to the Biwin Elite, both drives showed the same high performance that quickly dropped off in our testing. What was different about the Biwin Elite was the flash, 25nm synchronous IMFT flash. With that knowledge we determined the issue wasn't with the exotic 24nm flash, but the base code. The firmware was screwed and TRIM was no longer working. How could I of missed it went through my mind at least once a day for the next week.
The Biwin Elite arrived roughly three and a half months ago. Since then we've received 25 other SandForce based SSDs, all with the same issue, all with broken TRIM. A few of these products we've went ahead and reviewed, like the ADATA SP900, the first SandForce based drive with 0-provisioning and the SuperSSpeed Hyper Gold SLC, the first SLC flash drive we've tested in quite a long time. Basically we determined that any SSD coming to our lab would need to be re-tested and re-written once a firmware fix was available. Since the option wasn't very attractive we only published reviews of 'special' drives like the 0-provision and SLC.
At the time we were spoon fed the same line over and over, "two weeks". A new firmware "is close", "coming soon" and "in testing now." We really didn't expect two weeks to turn into five months, but our hands were tied to some degree because writing one review is tough enough, but writing two over the same product is exhausting.