Unlike most integrated motherboards PCSTATS has
reviewed, ATI has enabled IGP overclocking with the AMD 785G chipset. The
default clock is 500MHz, so it will be interesting to see what impact a
200-250MHz overclock will have on IGP performance.... anyway's let's begin.
always, overclocking starts off by dropping the multiplier
on the AMD Phenom II x4 955 Black Edition down to 8x, and disabling
features like Cool'n'quiet, CPU C1E power states. A set of DDR2-1600MHz memory
modules from Corsair was locked into the ASUS M4A785TD-V EVO and
set to run in DDR3-800 mode so it won't hold the CPU back - in this first
test we're trying to find the highest support bus speed.
The bus speed of the ASUS M4A785TD-V EVO
motherboard was then bumped up from 200MHz to 250MHz.... and 275MHz which caused
the system to crash while loading Windows Vista. A megahertz too far? After a
bit of fiddling, the bus speed was reduced to 265MHz, allowing Vista to boot
properly. Not the best overclock PCSTATS has squeezed from an AMD 785G board,
but not too shabby.
Integrated Graphics Overclocking
After finishing with the CPU, PCSTATS turned its attention to overclocking
the AMD Radeon HD 4200 IGP. The ability to overclock and integrated video
chipset is relatively new, and the results can boost performance a little.
The Radeon HD 4200 IGP is clocked at 500MHz by default. Overclocking from 500MHz
to 650MHz was easy, and pushing the AMD 785G IGP to 725MHz wasn't hard at
all. In a matter of minutes the IGP was operating at 775MHz without difficulty.
Once the Radeon HD 4200 IGP was overclocked, it was only
natural for PCSTATS to run some quick benchmarks to see what kind of performance
gains were actually achieved. The default 3Dmark 06 benchmark result for this board (IGP @ 500MHz) is
1686 3DMarks. Overclocking the Radeon HD 4200 IGP from 500MHz
to 775MHz improved this benchmark score to 2098 3Dmarks.