Corsair Force Series 120GB SSD review - PAGE 1

Has SSD technology really matured at this point? In the beginning, SSDs were suffering from write amplification, which made their writing performance decrease over time, up to a point where it would then stabilize, when all memory cells had been written at least once. What is this write amplification phenomenon, already? It's caused by the fact that SSDs must erase data in a sector before writing in new one. What causes problems is that the smallest part that can be erased, an erase block, is much larger than the smallest part that can be written. As a result, when all memory cells have been filled at least once, the SSD must always erase a large block, and then write back the data of that block that is meant to be conserved as well as the small portion of new data.

Then, appeared the TRIM function, which allows the operating system to tell the SSD which sector is not used anymore. Normally, a drive does not know anything about which cell is currently used or not in the file system. With TRIM, once the SSD is told that a certain portion can safely be erased, it erases it right away so there is no need to wait until the host sends some data to write next time.

TRIM is not perfect however. In some cases, the SSD is not sent that command. For example, it happens when a file is saved with a smaller size than its previous version; the data in the freed room is not erased.

There are many SSD controllers on the market now, and some have their own algorithms, focused on trying to minimize the performance cost of write amplification. There is a factor designed to measure write amplification, being the ratio between the number of write operations the SSD has to do and the number of write operations the host has asked. Recently, SandForce delivered its DuraClass technology, achieving write amplification factors below one, thanks to some data compression techniques and other algorithms that are kept secret. DuraClass also prevents the need for garbage collection, which many other SSDs require. All of that, without a memory cache.

So this is why there is so much hype around the SandForce controller. Some examples of SSDs using the SandForce controller are the Corsair Force Series, available for a few months now.

The previous SSDs in the Force Series featured capacities of 50, 100 and 200GB due to the larger overhead, more suited for writing-intensive uses where a longer drive longevity is required. In a desktop environment however, a smaller overhead is more appropriate, providing the user with more storage capacity. That's how the 60, 120 and 240GB Force drives are born. Today Neoseeker examines the 120GB version of the Corsair Force SSD.

Specifications

The 60GB and 240GB drives differ only by their capacity. So how will these new drives in the Force Series perform? The following pages ought to answer that question.