Custom Resolution Utility (CRU)

[ToastyX]

(09-17-2015 06:48 PM)falkentyne Wrote:  is there a technical reason why video cards don't downclock the memory (or sometimes the core) from load speeds, when the Vertical Total is lower than the default? Is this a hardware limitation or by design?

The memory needs to be retrained after changing clock speeds. This is done between screen refreshes during the vertical blanking period to avoid screen flicker. If the vertical blanking period is not long enough, there won't be enough time to refresh the memory contents before the next screen refresh.

AMD cards are also hard-coded to switch clock profiles when video acceleration is active even if the memory clock is not supposed to change. That's why the screen gets corrupted with a lower vertical total when video acceleration is active with the memory overclocked.