AMD Bulldozer / FX-8150 Desktop Performance Review

Computer hardware enthusiasts have literally waited for years for AMD's Bulldozer architecture to come to market and we finally see this today in its desktop form, code named Zambezi, brand named AMD FX. In this article we share with you our analysis of Bulldozer's performance in synthetic benchmarks and desktop applications.


Power Consumption

All power readings were taken at the wall with a Kill-A-Watt device. Very simple to do. Power used by your system is going to be greatly determined by the efficiency of your power supply. Let's say you are pulling 500 watts at the wall and your system uses an aging PSU that is giving you 80% efficiency, that is only 400 watts being used by your computer system, the other 100 watts is being utilized and for the most part wasted by your PSU doing the AC/DC conversion. Newer PSUs can pull up to and over 90% efficiency ratings.

Our system consists of two Corsair F120 SSD, a Corsair H100 CPU Water Cooler, Corsair RAM, and a Thermaltake 1200W Toughpower PSU. One additional 120MM fan is also plugged in. All controllers on our motherboards are turned off that are not needed for the testing. This data is taken across three different motherboards, so your mileage may vary and it is hard to considering this testing 100% objective, but this is the only way we have to do it with our resources.

Idle wattage consumption below is shown with the system at rest at the desktop. Power saving features are turned on inside the motherboard BIOS.

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Our stock clock idle wattages are are fairly slim across the board when comparing the Sandy Bridge and Bulldozer parts. We are looking at a delta of 12 watts at the most at stock clock idles giving the edge to Sandy Bridge. Conversely, when overclocked we see the exact opposite result, our overclocked Bulldozer parts are more efficient than Sandy Bridge at idle. AMD has been talking about its power gating for years now on Bulldozer and that is one thing that has seemingly come to fruition.

The fact that your 4.6GHz overclocked Bulldozer system will be sitting there idling at 120 watts is not a bad thing at all.

Seeing the older overclocked i7-920 surely puts it all in to perspective though.

Probably what is most impressive is the i7-990X. The die size process between that CPU and the previous 920 generation is easily seen, and keep in mind that the 990X is clocked at 4.54GHz.

Loaded wattages are using Prime95 Small FFTs; these do NOT stress the RAM and therefore the memory controllers. So these loaded wattages look very much at "CPU Power," even though we have to consider the memory controller is now on-die. You can surely load up these systems further, but we thought this might give us a more granular view of "CPU" power.

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First off we see what overclocking can do to our power usage. This new overclocking stuff is going to be very hard to get classified as "green." wink You will quickly notice that our 2500K Sandy Bridge system only surpasses our stock 8120 by 10 watts. Pushing the 8120, or 8150, to the 4.6GHz mark takes an extra 200 watts of power at load compared to stock clocks. On the upside, Bulldozer does not suck as bad as that old 45nm Nehalem, but the new 32nm 990X still pulls lower wattages than Bulldozer.

AMD's Bulldozer fits its code name in the power department when loaded. The idle wattages were surely lower than we expected and very much welcomed.