AMD Athlon X2 7750 BE review - Socket - Power Consumption - Overclocking

Socket AM2+

The Athlon X2 Series 7000 processors make use of socket AM2+, an improved socket design based on socket AM2. Luckily there's no added pin count. So a Phenom processor will theoretically work in an AM2 mainboard as well (BIOS update required). The difference however has to do with the integrated memory controller and voltage routing. Voltages for the cores and memory controllers can be set independently from each other on Socket AM2+, which in the end has everything to do with power consumption. With socket AM2+ you'll also be able to make use of DDR2-1066 MHz memory, while on socket AM2 you'll be limited to 800 MHz. Last but not least, the socket change was needed for HyperTransport bus 3.0. which supports speeds up to 2.6 GHz.

So Kuma may be used on motherboards with socket AM2+, make sure though you install the latest BIOS upgrade before installing this processor.

Power Consumption

We already touched on the subject a little. The Athlon X2 Series 7000 processors have a TDP (peak wattage) of 95W. Now that by itself is interesting as it's the same as the mid-range specced Phenom X3 and X4 processors. Now we should have two active & independent cores here, but I'm 99.99% certain that two other cores are to be found in there, yet are disabled. This explains the transistor count and TDP.

Native independant cores are cool though. Each core can be clocked down independently if not utilized, saving heaps of current. There's also a new status called C1E (check in the BIOS of your mainboard). If the processors are temporarily inactive, they can pretty much put themselves in sleep-mode (clocking down). HyperTransport will power down and a low-power stage is activated on the memory. Good stuff in this more aware green world.

Let's examine:

Now since we use an AMD 790GX based chipset, we have the advantage of an integrated GPU, so no dedicated graphics card was required or installed. This makes 790GX in combo with a modern processors, very energy efficient. In an idle state the computer will consume less than a 100 Watts. With the 7750 BE processor at standard clock, with the two CPU cores 100% stressed we max out at 170 Watts.

Once we start to overclock the processor towards 3200 MHz, the power consumption gradually increased, 114 Watt in idle, and the PC drew 185 Watt with the 4 cores stressed (Prime95 test).
 

Athlon X2 7750 BE overclocking
If you decide to start an overclocking session with the processor; trust me you are better off with the BE edition and the combo of an AMD 790GX/FX based mainboard. Key to the new 790FX/GX series is AMD's Overdrive interface that allows effortless overclocking of the Black Edition processors.

The significant performance increase the platform can deliver to gamers using Black Edition processors is thanks to what AMD calls Advanced Clock Calibration technology. The new revision Athlon X2 and Phenom B3 processors can complement the 790FX/GX chipset's overclocking capabilities very well.

The Athlon X2 7750 BE processor is multiplier unlocked, so that made overclocking pretty easy really. We increased the core CPU voltage to 1.4 volts, and increased the multiplier until we ended up with a hanging system or couldn't boot into Windows any longer. Granted, the 7750 BE shows a lot of potential as we got the core clock up to 3200 MHZ, easily.

At 3300 MHz on a really standard crappy cooler I stumbled into a boot issue with Windows though. But with some decent cooling or even liquid cooling, the results could be much higher. I wouldn't be surprised to see some of you hit 3.6 - 3.7 GHz.

What we'll do in this review is include the overclocked results we yielded at 3200 MHz throughout all benchmark sessions. This overclock only cost us 15 Watts of additional power consumption. Well worth the effort.