AMD's Bulldozer Architecture: Overclocking Efficiency Explored

By Achim Roos, Manuel Masiero
published

AMD’s FX processor line-up was supposedly designed with efficiency in mind, according to AMD. We're putting this claim to the test, assessing the Bulldozer architecture at a number of different clock rates and comparing the results to Intel's CPUs.

Efficiency Score And Power Diagram

When the performance per watt is plotted, it becomes obvious that the Bulldozer-based processors are most efficient when the voltage to them is as low as possible. Undervolting does not even result in a performance hit when you use it with the FX-8150's default reference clock and multiplier setting.

Achim Roos
Achim Roos
77 Comments Comment from the forums
  • aznshinobi
    Reading conclusion paragraph, I'd have to agree. I think they probably would've been better of using the STARS arch and just die shrinking it to 32nm.
    Reply
  • Darkerson
    I know I have been critical in my comments here and there, but I really do hope Bulldozer helps AMD learn and refine Piledriver and future CPUs so that they are all better as a result. I know I will be skipping BD, but that doesnt mean I dont ever want to use AMD again. I will always root for the underdog, in hopes that we have another Athlon 64 on our hands again.
    Reply
  • hellfire24
    gulftown=expensive and useless.
    Sandybridges=king of the hill(price to performance)
    Sandybridge-E=expensive sandybridge.
    Bulldozer=budget cpu with multitasking capabilities.
    Reply
  • deadon2
    Fehh... did my build on a 990fx platform with a 955be CPU. Runs plenty fast, and I can upgrade the AM3+ in a year when AMD gets it right.

    Although I appreciate the work done on this article...

    Nothing to see here folks, move along...
    Reply
  • dontcrosthestreams
    im just fine with my 110$ 955be.... 29 deg idle at 3.7ghz
    Reply
  • noob2222
    Is that a typo on page 7 and 8? "Clock Frequency: 4.5 GHz, Multiplier: 22.5x, CPU Voltage: 1.428 V" cpu-z shows 1.380? page 8 cpu z shows 1.44 and not 1.5.

    As for my own efficiency testing, I achieved 1.375V (cpu z), 4.4Ghz out of my 8120 with ease. I upped the NB to 1.115v (+.015V)wich added more stability and clocked the NB to 2600 to match HTT, wich brought another 1gb/s on sandra's memory test. All without disabling C1E or C3 states.

    Would be nice to see some followups with memory testing, BD responds to fast speeds. Hard to read since its in a different language but the graphs are easy enough to see
    http://www.planet3dnow.de/vbulletin/showthread.php?t=401023&garpg=13
    Reply
  • Tom's Hardware finds that overclocking increases speed, power requirements. Film at 11.
    Reply
  • de5_Roy
    yay! another efficiency article from toms. :love:
    sad to see amd's claims about efficiency turn out to be (much) less than accurate.
    some people are definitely gonna complain about the ram used (ddr3 1333) and windows 8 or lack of highly threaded benchmarks like truecrypt encryption or pov ray tracing (as if those are always used by regular users lol) and stuff.
    undervolting does look promising...but it doesn't seem to make any difference compared to sandy bridge systems. worse, bulldozer needs voltage increase to get more clockspeed.. i guess it will be more evident in fx 4100 and 6100 where substantial core voltage increase is necessary to get stock sandy bridge level performance out of them. that's just disappointing.
    Reply
  • memadmax
    It seems to me that Bulldozer is either a AMD bastard child chip, or it's a first gen chip of which subsequent generations of the architecture will be playing "catch up" performance wise. Otherwise, it's typical AMD trying to be efficient rather than a heavy hitter.

    But if you ask me, this is a "defensive" chip in the processor wars. And no war has been won playing defense.
    Reply
  • shinkueagle
    memadmaxIt seems to me that Bulldozer is either a AMD bastard child chip, or it's a first gen chip of which subsequent generations of the architecture will be playing "catch up" performance wise. Otherwise, it's typical AMD trying to be efficient rather than a heavy hitter.But if you ask me, this is a "defensive" chip in the processor wars. And no war has been won playing defense.
    Meaning this war is a TOTAL loss to AMD... SADLY... AMD - ABSURDLY MORONIC DEVICES.
    Reply