skirtingi gpu atminties kontroleriai.

Even bigger however are the enhancements to Cypress’s memory controller, 
which allow it to utilize a number of power-saving tricks with GDDR5 RAM, 
along with other features that we’ll get to in a bit. With RV770’s memory 
controller, it was not capable of taking advantage of very many of GDDR5’s 
advanced features besides the higher bandwidth abilities. Lacking this full 
bag of tricks, RV770 and its derivatives were unable to reduce the memory 
clock speed, which is why the 4870 and other products had such high memory 
clock speeds even at idle. In turn this limited the reduction in power 
consumption attained by idling GDDR5 modules.

With Cypress AMD has implemented nearly the entire suite of GDDR5’s power 
saving features, allowing them to reduce the power usage of the memory 
controller and the GDDR5 modules themselves. As with the improvements to the 
core clock, key among the improvement in memory power usage is the ability 
to go to much lower memory clock speeds, using fast GDDR5 link re-training 
to quickly switch the memory clock speed and voltage without inducing 
glitches. AMD is also now using GDDR5’s low power strobe mode, which in turn 
allows the memory controller to save power by turning off the clock data 
recovery mechanism. When discussing the matter with AMD, they compared these 
changes to putting the memory modules and memory controller into a 
GDDR3-like mode, which is a fair description of how GDDR5 behaves when its 
high-speed features are not enabled.


http://www.anandtech.com/video/showdoc.aspx?i=3643&p=11  ir sekantis psl. 
apie naujesnius gddr5 navarotus


"Icetom" <kkk@kk.com> wrote in message 
news:h9nc03$b8e$2@trimpas.omnitel.net...
> Jo neblogai ir dar žinant, kad jos našumas prilygsta HD4870x2 modeliui.
>
> Man tik nesuprantama, kodėl ATI-AMD ir jo partneriai neišleidžia firmware 
> atnaujinimo HD48xx modeliams su sumažintais atminties dažniais. Nes VGA 
> RAM daugiausia ir naudoja elektros idle metu: