Legit Processor Reviews
AMD A8-3850 APU Overclocking w/ 7 Processors
|Date:||Tue, Aug 23, 2011 - 12:00 AM|
|Written By:||Nathan Kirsch -|
AMD Fusion APU Overclocking
When AMD released the 'Lynx' desktop platform back in June 2011, our motherboard reviewer ran into some bad luck when overclocking the processor. When you get a new platform setup for the very first time you really don't know what to expect and it does take some time to learn all the quirks and nuances of a new processor and motherboard. When our motherboard reviewer, Dan Stoltz, reviewed the ASUS F1A75-M motherboard and the MSI A75MA-G55 motherboard we found that the AMD A8-3850 that we had wasn't a good overclocker. Some people think that AMD likes to send out cherry picked processors, but trust us that isn't the case.
Since we want to see how well AMD A75 chipset powered motherboard overclock we got our hands on six additional AMD A8-3850 tray processors and now had a total of seven of them in our possession. Our point of doing this was to get the best one for our test system. After testing each processor we thought we'd share the results with you as this is a great example of what you can expect when you buy a processor.
The A8-3850 has a 2.9GHz quad-core CPU, 600MHz GPU w/ 400 Radeon cores, 4MB of L2 cache and a 100W TDP. The processor
has a base clock of 100MHz with a multiplier of 29. This is a locked
multiplier, so you can lower the multiplier in the BIOS, but you can not
increase it. That means for overclocking we are limited to just
increasing the base clock frequency in the motherboards BIOS.
For testing we used the ASRock A75 Pro4 motherboard with a Ultra Carbon X5 CPU cooler and set the vCore at 1.500V and started cranking up the baseclock or bus speed on the seven processors that we had. Stock voltage on this board was 1.325V. We didn't go crazy with the voltage, but we did find some differences between the seven processors that we had in our possession with this voltage bump.
| AMD A8-3850 APU
|| Max Frequency
| CPU #1
||114MHz|| 3303.1 MHz
|CPU #2||127MHz||3679.5 MHz|
|CPU #3||127MHz||3679.5 MHz|
|CPU #4||127MHz||3679.5 MHz|
|CPU #5||127MHz||3679.5 MHz|
|CPU #6||127MHz|| 3679.5 MHz
|CPU #7||132MHz||3826.5 MHz|
The original test sample that AMD sent us actually turned out being the least overclockable APU and was able to hit just 114 MHz on the baseclock for final clock frequency of 3.30 GHz. The best overclocker in the group of seven was an APU that could run stable at 132 MHz or 3.83 GHz.
As you can see the difference between the best and worst processor was 523.4 MHz, which is very significant. The other five AMD A8-3850 APU's all topped our at 127MHz or 3.70GHz. It was a little shocking to see the vast majority of the processors hitting the same speed, but to see six out of the seven APUs reaching 800MHz overclocks was very nice.
Just to show you the advantages of overclocking here is a 3DMark Vantage run showing the score a stock AMD A8-3850 APU being P4166 and then our best overclocker running 3.83GHz having a score of P5059! We were able to break the 5,000 mark by the overclock. Getting a 21% boost in the benchmarks is a nice performance gain!
At the end of the day we found that once again not all processors overclock to the same level and that our original AMD A8-3850 APU was a poor overclocker. We'll be updating our motherboard test system to the best overclocking processor as we want to make sure we aren't processor limited as we want to show you the differences between different brands and not be held back by a Fusion APU that wasn't overclocking to a level that we expected.
Usually we don't show what goes on behind the scenes of Legit Reviews, but we thought you'd get a kick out of it. If you'd like to see more short articles like this in the future be sure to let us know!
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