|AMD A8-3850 Lynx APU Processor|
|Reviews - Featured Reviews: Processors|
|Written by Hank Tolman|
|Thursday, 30 June 2011|
Page 13 of 15
Overclocking the Lynx platform is quite a bit more difficult than it was on the previous generation of AMD platforms. The Athlon-II and Phenom-II series of CPUs were excellent overclockers, and it was easy to do. With Black Edition Processors, the CPU multiplier was unlocked and you could crank it up as high as it would go and still boot. This is the best way to overclock the CPU alone, as increasing the reference clock ends up overclocking the RAM and GPU (if one is onboard) as well. On the A-Series APUs, however, the reference clock is the only way to overclock. Overclocking enthusiasts were dismayed when the Sandy Bridge CPUs were locked down tight on the H67 boards and severely limited on the P67 boards. Luckily, the AMD A-Series APUs are not limited to Turbo overclocking only, but, as I said, the only way to overclock them is through increasing the reference clock. The CPU and GPU are completely locked.
With the ASUS F1A75-M PRO motherboard, even overclocking with just the reference clock was a breeze. With the voltage set to AUTO, it automatically increased based on where the reference clock was at. The only tweaking I really had to do was playing around with the numbers to get the highest overclock possible. I also had to tune down the RAM settings because the reference clock hits everything, so the RAM was out of its league while the CPU and GPU were still cooking.
I started off the overclocking by increasing the reference clock from 100MHz to 125MHz. Everything ran solid at that level, so I continued on. At 133MHz I was able to boot into Windows fine, but the stress testing failed. I scaled back 1MHz at a time to 130MHz, where everything past the testing. I had to scale back the RAM a little as well. The RAM I am using is rated for 1600MHz, so overclocked it got a little too high. I scaled back to what would normally be 1333MHz on the RAM so it sat at 1733MHz after the overclock. Here are the results.
3DMark 11 shows a dramatic 51% increase after the overclock. The 3DMark Vantage shows a much lower 18% increase, but that is still quite respectable.
The Sandra Whetstone tests a 32% increase in performance after the overclock, while the Dhrystone tests improve by almost 30%.
The Cinebench Single CPU test performance increased by 30% while the multi-core CPU test increased by 32%.
Overall, the overclocking of the A8-3850, while severly gimped, was still extremely successful in improving the performance of both the CPU and GPU functions of the APU.
The A8-3850 runs very cool. This seems to be a trend with 32nm processors and is one that I look forward to the industry enhancing in the future. When testing the temperature of the A8-3850, the ambient temperature stayed at a constant 22 degrees Celsius.
Power Consumption was very impressive as well. With discrete level graphics, I would have expected a much higher pull from the system. The following is a measure of the power consumption of the complete system at certain points during operation. Measurements were taking with a P3 Kill-A-Watt meter. While these wattages are somewhat low, it is important to note that they are definitely higher than the Sandy Bridge H67 platform with an i5-2500K CPU.