Test bed & overclocking
In order to be able to squeeze as much juice as possible from 6350’s cores, I used one of the best AM3+ motherboards on the market - the Crosshair V Formula from the ASUS ROG lineup. I don’t deny the board had some problems at its initial launched, but these seem to be all related to the past. I completed the test bed with an ASUS ROG VGA - Radeon HD 7970 DirectCU II TOP - 2x4GB GeIL Evo Two 2400MHz 10-11-11-30 DDR3 kit, Noctua NH-U12S heatsink equipped with 2 Noctua NF-F12 PWM fans and Antec Signature 850W PSU.
As I said, it is pretty interesting, even intriguing that FX-6350 is a bit cheaper than FX-8120, so I decided to compare the two. Maybe some of you were expecting to see the FX-6350 against the brand new Intel Haswell CPUs. But as I said before, AMD lost this battle long time ago, so I see no point in showing the obvious.
Maybe because of the unlock multiplier, some of you think that overclocking the FX parts is a walk in the park. Well, you would be terribly wrong. The FX-6350 has a high TDP and the power consumption tends to increase a lot on all Vishera parts when increasing voltage. So, you want to be very careful so that the board does not throttles down the CPUs or activates its internal protection function. These being said, I soon discovered that the max. voltage I could apply in BIOS was 1.4875V. Anything higher than that would have brought the full machine to a full stop as a protection mechanism not to burn some of the components. Of course, thanks to the mobo’s LLC function, the real voltage under full load was 1.536V. This is how I was able to raise the CPU’s frequency above 4.6GHz. I used a 23x multiplier for a targeted 202MHz bus speed. The real bus applied by the motherboard was a bit higher - 202.68MHz, which finally led to an operating frequency of 4661MHz. To achieve this, I deactivated all functions meant to reduce power consumption and I blocked the fans to full RPM. When running stock settings, these functions were kept active, while running the fans at full speed. After testing the CPU’s stability, I pushed forward with the overclocking and managed to squeeze 2634MHz from the CPU/NB and HT Link, while maintaining a 2432MHz for the RAM.
As you can see below, the system was perfectly stable using these settings:
I did the same with the FX-8120 CPU, only that I had to stop at 4.4GHz, achieved by applying a 22x multiplier to the 200MHz bus.
Now that I showed you what I tested, I still have to tell you how I did it. Well, I used the following aps:
- PCMark 8: Home, Creative and Work modules;
- 3DMark: Ice Storm, Cloud Gate, Fire Strike and Fire Strike Extreme modules;
- AIDA64: CPU benchmarks, FPU benchmarks and Memory benchmarks;
- PassMark’s PerformanceTest for the CPU;
- Wprime: 32M and 1024M;
- Hyper PI: 1M, 8M, 16M and 32M;
- 7-Zip: Compressing and Decompressing speeds;
- TrueCrypt: Encryption, Decryption and Mean;
- CINEBENCH: CPU and GPU;
- MediaCoder iPhone Edition: transcoding a 40Mbps 1080P MKV 102s file to iPhone format;
- Games: BioShock Infinite, DiRT Showdown, GRID 2, Hitman Absolution, Sleeping Dogs, Tomb Raider and Total War Shogun 2, all running in highest details, with 1920x1080 resolution.
In the end, I measured temperatures and power consumption while maintaining a 260C room temperature.