Solid-state hard drives trade the rapidly spinning magnetic platters and multiple moving read/write heads of a traditional hard drive for a bank of the same type of memory chips used in USB drives, cell phones and digital camera memory cards. While they're made with memory chips, they aren't RAM. SSDs use a different type of memory, can't be directly accessed by your computer's processor, and are much slower than RAM. They can, however, make an even bigger difference in your computer's performance than adding RAM though.

How SSDs Work

Outside of the box, an SSD works like any other hard drive. Your computer's CPU requests data from the motherboard chipset, which sends the request to the hard drive. As of the date of publication, data transfers in and out of the SSD on a 6Gbps serial advanced technology attachment, usually called SATA, connection, one bit at a time. Inside the drive, a controller pulls the information off or puts it on the many flash memory chips that it contains.

How RAM Works

RAM enjoys an almost direct connection to the CPU. In fact, data flowing to and from the hard drive goes through the computer's RAM on its way. RAM chips are also driven by a memory controller, but they are synchronized to the processor's clock so that they can deliver or accept data exactly when the processor needs. The communication path between the CPU and the RAM is also much wider than an SATA connection -- 64 bits is common in mid-2013. RAM's key drawback other than its cost is that when the power goes out, it loses everything it stores.

SSD vs. RAM Speed

RAM is orders of magnitude faster than an SSD. A SSD's theoretical maximum transfer speed is that of the SATA interface -- 6Gbps, which is equivalent to 750MB/sec. A relatively fast SSD may achieve real-world write speeds of 456MB/sec, though. The theoretical maximum speed of RAM is in its PC number, so a module of PC3-12800 memory can transfer 12,800MB/sec--roughly 30 times faster than the real world performance of an SSD. Directly substituting an SSD for RAM would end up significantly slowing down your system.

Real-World Performance

However, in the real world, spending your money on an SSD may make more of a difference than adding RAM. The old rule that adding RAM improves performance breaks down when you already have enough RAM to do what you want. For many users, four to eight GB of memory provides excellent performance. At that point, swapping a relatively slow hard drive for a speedy SSD will make a noticeable difference in how quickly your computer boots up and how quickly programs open. If your operating system needs to use a page file, which is a chunk of your hard disk set aside as a bit of just-in-case memory, a page file stored on an SSD will also be faster.

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Shenzhen KingSpec Electronics Technology Co., Ltd. was established in 2007. KingSpec factory has the abilities of hardware design and development, manufacture and wholesale. KingSpec has been entitled as “National High-tech Enterprise” by Chinese Governments yearly. We are looking forward to cooperate with you.