RAM is thousands to millions of times faster than SSD

[hieuhtr]

1. Let’s look at typical speed scales of RAM, SSD and rotating disks. A typical reference to RAM is in the area of 100ns, accessing data on a SSD 150μs (so 1500 times of the RAM) and accessing data on a rotating disk 10ms (so 100.000 times the RAM).

2. RAM is hugely faster. A typical SSD has a random access time of ~100 microseconds, while typical RAM has access times of a few nanoseconds or even less for onboard RAM. So the RAM is thousands to millions of times faster. You would not like performance of your computer if you used the SSD for main memory. The trade-offs between speed, cost, power, and volatility is why computers have evolved to have a hierarchy of memory - from fast, expensive, volatile, and power-hungry onboard cache memory to slow, cheap, non-volatile HDD or SSD