Bests & Worsts Reviews from Amazon

Dear Amazon, This review was written for Sandisk Extreme, not Sandisk Extreme II. It has nothing to say about the newer model. Your editors have erred in conflating the reviews for these two different products. Readers please note that Sandisk has, after many months, corrected the problems cited in this review, so those complaints are now irrelevant. However, my comments on the corporation's lack of integrity and honesty still stand. ----------------------------------------------------------------------------------------- This is probably the fastest and most reliable SSD in its price class...except for it failing to deliver its rated speed due to defective firmware. The problem occurs with MacBooks and desktop models that use the NVidia SATA controller. (You can see the controller under System Profiler->Serial-ATA.) The Sandisk Extreme will connect at a negotiated link speed half that of the controller. That means for a SATA 2 (3 Gbps) controller, transfer speeds will be limited to about 120 MB/s, a quarter of the SSD's rated speed. SATA 3 (6 Gbps) will be limited to about 250 MB/s in practice. This problem of reduced link speed has appeared extensively with various combinations of SSD brands and Mac models. Both OWC and OCZ have already issued firmware updates that correct the problem, giving their customers the full speed capacity of their SSDs. As of the writing, Sandisk has not corrected the problem, nor committed to doing so. If you are thinking of installing any SSD in a Mac, I suggest you first search for "negotiated link speed" <your mac model> <ssd model> to find out whether your particular combination will suffer this defect. As for myself, after days of research, waiting for a good price, and great anticipation, I will be returning my Sandisk Extreme tomorrow. So disappointed. (MacBook late 2009; SATA 2 NVidia controller; Sandisk Extreme 240GB) Update 19-July-2012: I spoke with Sandisk technical support (in India). They acknowledge a problem with slow link speeds with the NVidia MCP79 controller. Here is their email response: We really apologize for the inconvienience caused to you, however we would like to inform you that this is a known issue wih Sandisk and this issue has already been escalated to the R&D team for research and we are expecting a fix on this issue pretty soon regarding the compatibility of Nvidia MCP79 graphics card and Macbook pro and the Sandisk SSD getting the appropriate speed as per design. Update 3-August-2012: My attempts to get useful information from SanDisk have turned into a series of Kafkaesque bureaucratic runarounds. After hours on the phone and countless emails with clueless and evasive support technicians, I have learned only the following: 1) The problem of connecting at half the SATA controller speed occurs with several different nVidia controllers. 2) The issue has been "escalated to the R&D department". R&D has known of the defect since March. 3) Since March, SanDisk has failed to either issue a fix or to inform potential buyers that this SSD may not work at full speed in their computer. 4) The Corporation will not state "if and when SanDisk will make firmware updates for specific chipset versions or OS." So I suggest again that before buying this SSD you thoroughly research whether the link speed defect occurs with your particular SATA controller. At this point I have no confidence that SanDisk will issue a fix, nor in the integrity of the company to respond to the needs of (actual and potential) customers honestly and effectively. I will monitor the situation until August 20, 2012 (the return date), and will update here if a fix is issued by then. Update 21-August-2012 Thanks for the feedback. I feel happy to have saved some people from the hassle I have experienced with this product. Today's call to SanDisk confirms that they know of the issue, have no fix, and no date for a fix. The support agent even suggested it was best to RMA the device at this point. And, gentle readers, it gets worse. Some of you may understand what the TRIM command is. TRIM is sent by the OS to inform the SSD which blocks are no longer in use. This information in turn allows the SSD to garbage collect those blocks, which keeps the SSD's write speed up to spec. It turns out that both TRIM and garbage collection are poorly implemented in this SSD. After use (2x filled), its write speed falls to 15-30% of its initial speed. Issuing TRIM restores write speed to about 60% of rated speed, but apparently after use the SSD can never regain its fresh-out-of-box rated write speeds. You can view the actual measurements here: [...] This problem with GC and TRIM seems to affect *all* SSDs based on the newest SandForce 2281 controller, not just SanDisk's. The manufacturers have known about this defect for five months. Apparently, all the various Corporations though it was unimportant to let their customers know we are buying defective products that will irrecoverably lose their rated write speed after use. You can read the sordid details here: [...] Rumor is that SandForce has already issued a firmware update that fixes TRIM/GC. We are waiting for the various manufacturers to customize it and issue their own updates. Any day now. In case you have not caught it, I am angry and fed up. Angry at SanDisk for wasting my time and money by failing to disclose two major defects. That's called lying everywhere outside of corporate culture and politics. Fed up with most of the SSD manufacturers for burdening the customer with onerous firmware updates and known firmware defects. For turning us into their quality control engineers by shipping DOA and soon-to-fail hardware - just look at the customer feedback on Amazon. Surely the bean counters have figured out it's cheaper to ship defective product and force the customer to sort it out than to test the units themselves. Someone asked what SSD I would recommend. Take a look at the first link above and note the models that do not degrade with use and that respond properly to TRIM. Those happen to be the ones without the SandForce controller. Next look at the percentage of 1 and 2 star reviews. (Yes, I understand that reviews are biased toward the negative, but they still indicate your relative odds of getting a lemon.) Next search for others' experiences with that SSD and your computer/SATA controller, to make sure it is compatible. Lotta work... to buy a device that is marketed as working out of the box. For my MacBook, late 2009, the only one I see that makes the cut is Samsung 830, with few reported defects and decent sustained performance. But speaking strictly for me, I am out of the SSD market. I'm going to reinstall my trusty, slow mechanical hard drive, and wait six months. Maybe by then the manufacturers will have received enough blowback to be selling products that actually work well and reliably. Maybe. ------------------------------------------------------------ Looks like Amazon does not allow links in these reviews. To find the performance measurements cited above, search for "SanDisk Extreme SSD 240 GB Review" at XBit Labs. Page 4. The TRIM problem is documented in the article "LSI SandForce 5 Series SSD Firmware" at TweakTown. Good luck, and do your research before rolling the dice. ------------------------------------------------------------------ Update 9-October-2012. Still no fix for these two issues. Still no word from SanDisk stating when, or if ever, they will be fixed. ------------------------------------------------------------------- Update 22-October-2012 SanDisk has at last released firmware update R211 that is supposed to fix the TRIM command. R211m claims to fix the negotiated link speed issue with nVidia SATA controllers. Cautious buyers may want to wait until reliable independent testing labs verify that the issues are truly fixed and that no new bugs were introduced. After all, SanDisk and others have released buggy firmware before, and concealed that fact even after knowing about it. Good luck to you!