AMD 785G Chipset Launch: ASUS and Gigabyte
Overclocking the IGP with HL2
Our last gaming benchmark is Half-Life 2: Episode 2.
||Thanks to the dedication of hardcore PC gamers and a huge mod-community, the original Half-Life became one of the most successful first person shooters of all time. And thanks to an updated game engine, gorgeous visual, and intelligent weapon and level design, Half Life 2 became just as popular. Episode 2 offers a number of visual enhancements including better looking transparent texture anti-aliasing. We used a custom recorded timedemo file to benchmark all cards in this test.|
The Half-Life 2 benchmark gave some interesting results. For the first time, the AMD 785G caught up with the GeForce 9300. Both chipsets produced very playable frame rates at high image quality settings. We also see that the ASUS board seems to lag behind the Gigabyte board a little bit at 800x600, though not by enough to really make any difference. The difference dissapears at 1280x720.
The AMD 785G is aimed at the mainstream and is hardly marketed at the overclocking crowd. None of the AMD 785G boards are even equipped with anything beyond basic cooling. However, we couldn't resist trying our hand at some quick, rough and dirty OC'ing.
The first thing we found, nearly immediately, is that the 785G doesn't especially like having its CPU overclocked. Were weren't able to get very far with the HT clock at all, encountering stability issues as early as 240MHz, up from the stock of 200MHz. We did notice, however, that the system continued to show some signs of momentary stability well beyond 280MHz, though it was still much too unstable to even stay booted in Windows reliably. Perhaps some additional cooling could lead to some better results.
The next thing we found out is the IGP absolutely loved being overclocked. The amount of headroom left in the Radeon HD 4200 is phenomenal. Without any effort we were able to punch up the HD 4200's core clock from the stock of 500MHz to 650MHz. With a little extra voltage we were able to just touch 800MHz, though with somewhat questionable stability. At that point to decided to apply some extra cooling to the northbridge, in the form of a 80CFM case fan. We set up the fan to blow directly onto the northbridge heatsink and with some extra juice we pushed the Radeon HD 4200 to an impressive 1000MHz, twice the stock frequency. We were able to achieve this with both the ASUS M4A785TD-V EVO and the Gigabyte GA-MA785GMT-UD2H.
As you can see, doubling the clock frequency boosts performance quite tangibly. Even at the fairly impressive overclock of 1000MHz, we still felt that there was still some more room left. With a new, beefier northbridge heatsink, possibly water cooled, we'd bet it would be entirely possible to get even higher frequencies out of the 785G.
Overall, it looks like there is plenty of headroom left in the AMD 785G northbridge, or at least the Radeon HD 4200 portion of it. This is pure speculation, but given what we've seen here, we wouldn't be too surprised if AMD released a new chipset down the road that was just the 785G with a higher IGP clock and possibly a new southbridge.