sequential read/write and random read/write

If that ssd is for performance, you will be very disappointed. MLC units are notorious for long write delays. The cheapest unit that is any good is the intel x25-m at $600+. anandtech had a good article on this.

For performance get a velociraptor.

MLC is a completely different kind of flash memory. I wouldn't buy any MLC based drive right now except the Intel X25-M - most of them tend to have problems, especially with the random writes. If you want fast, but can't afford the $400+ for a good SLC SSD (or the Intel drive), I'd go with a 150GB Velociraptor.

Not if you need random performance. Raid is great for sequentials, but it will never accelerate the random reads and writes to the speed that a single velociraptor can achieve.

well it's been a long time but ,here goes,sequential read/write,is exactly what it says that the data is written sequentially as in 12345 etc,that is relative to it's offset on the hdd,,[just another way of saying it's address], random read write as in testing a hdd's access speed is usually derived from a "seed" # and the data is written randomly,these functions are used usually to calculate a hdd's access speeds and,may or may not include the hdd's head's latency..