Asus seems to have the best implementations of A85X so far. I have an ASUS F2A85-V PRO and a Gigabyte F2A85X-UP4 and have severe overheating problems when trying to overclock an A10-5800K on the UP4 past 4600, with temps in Prime95 going over 80C, meanwhile the V-PRO easily does 4900 in Prime95 at about 54C.
Asus gives you access to Digi+ VRM in windows through its AI Suite II (recently updated again), while Gigabyte's UEFI only gives you the two basic LLC settings. The following test I did on the ASUS wouldn't be possible on the UP4 as it is implemented at the moment.
Using the standard APU frequency of 100MHz and incrementing the APU Multiplier from 38X to 50X I've attempted overclocks with the default Digi+VRM settings and then using the Smart Digi+ key in AI Suite II from 3800MHz to 5000MHz. LLC settings in my test were made using the optimized VRM setting facility in AI Suite II on Asus boards. I first set and apply the Multiplier/Frequency in Turbo EVO then go into DIGI+ Power Control and click the colored Smart DIGI+ Key which generates an appropriate setting for the applied OC.
The CPU voltage required in each OC to pass 30 minutes in Prime95 is given with the number of 0.00625V steps above or below the default setting of 1.3125V.
Code:
+------+---------------+---------------+
|CpuMHz|.Default VRM...|.SmartDigi+Key.|
|ApuFrq+-----+---------+-----+---------+
| =100 | -/+*|..Vcore..|.-/+.| .Vcore..|
+------+-----+---------+-----+---------+
| 3800 | -15 | 1.21875 | -19 | 1.19375 |
| 3900 | -10 | 1.25000 | -16 | 1.21250 |
| 4000 | -05 | 1.28125 | -12 | 1.23750 |
| 4100 | +02 | 1.32500 | -07 | 1.26875 |
| 4200 | +07 | 1.35625 | -02 | 1.30000 |
| 4300 | +13 | 1.39375 | +05 | 1.34375 |
| 4400 | +18 | 1.42500 | +10 | 1.37500 |
| 4500 | +26 | 1.47500 | +17 | 1.41875 |
| 4600 | +38 | 1.55000 | +24 | 1.46250 |
| 4700 | +50 | 1.62500 | +34 | 1.52500 |
| 4800 | +62 | 1.70000 | +46 | 1.60000 |
| 4900 | 80+ | 1.8125+ | +60 | 1.68750 |
| 5000 | 80+#| 1.8125+ | 80+ | 1.8125+ |
+------+-----+---------+-----+---------+
| * 1.3125V to 1.9V = 94 x 0.00625V....|
| # 80+ = Prime95 fails below 1.8125V..|
+--------------------------------------+