Originally Posted by BlueDream
ati gpu card number mean
1st HD is high definition
2nd is 1st number like 3xxx, 4xxx, 5xxx, 6xxx is model also this number tell about direct-x card, stream processors (more big number high stream processors)
3rd is 2nd number like x3xx, x4xx, x5xx, x9xx is base memory (memory bandwidth) more big mean more memory bandwidth (e.g hd65
70 with 64Gb/s and hd58
30 with 128Gb/s) - depend bit and ddr card use.
4th is 3rd number like xx5x, xx7x, xx9x is clock card use, more big number mean high clock
5th is last number mean 0 is original design, other number mean rework from original design.
* not all gpu full this rules, have like some gpu already overclock by manufacture or other se model.
** if get some wrong please tell me
that just confuses people
its more like
HD as High-def as you said
first number= which generation the card is from (1xxx, 3xxx or 5xxx etc)
second number= which tier the card aims for (budget, mid-range, gamer, enthusaist)(x4xx, 5 and 6 and x7xx, x8xx and x9xx)
third number= the higher the number, the better the card is in whatever tier its located at ie HD 5750 is slightly weaker than the 5770 but is located in the same mainstream/midrange tier.
4th number= usually is a 0 and doesn't have a specific meaning
and per AMD's tradition
budget, low profile, just below mainstream= x5xx and x6xx
gamer/approaching enthusiast= x8xx
dual GPU/enthusiast= x9xx or x99x
note that AMD has bumped all the cards up by 1 tier each that will confuse people if you don't keep track for (only for the 6xxx series of cards)