Noun
DDR1 (plural DDR1s)
Initialism of double data rate first generation.
DDR2 picks up where DDR1 leaves off, utilizing internal clock rates similar to DDR1, but is available at effective transfer rates of 400 MHz and higher. Source: Internet
In January 2009, 1 GB DDR1 was 2–3 times more expensive than 1 GB DDR2. Source: Internet