AMD Bulldozer - FX 8150 Performance Review

Product: AMD FX 8150 / Asus Crosshair V
Company: AMD
Author: James Prior
Editor: Charles Oliver
Date: October 11th, 2011


The primary and overriding consideration of the Bulldozer design team was performance/watt, biased towards the needs of server use requirements; throughput over individual core performance, and skewed towards integer performance in that throughput. The design was intended to be very clockable, and responds well to increased voltage and frequency with appropriate cooling as demonstrated by AMD's world record for highest clock frequency of a desktop processor. The shipping clocks are high, compared to the previous STARS generation of CPUs, with an improved version of AMD's Turbo CORE technology.

FX Demonstration at AMD Zambezi Tech Day

At launch there will be 4 models, two 8-core and one 6-core, and the branding reflects the core count; 8000 series have 8 cores, 6000 series have 6 cores, and 4000 series have 4 cores. These are priced very competitively, commensurate with their performance. All FX processors are multiplier and voltage unlocked, in keeping with their enthusiast target market. All FX processors will be based on the same 8-core die, meaning that the lower core count products have disabled module in them. AMD are not permitting core unlocking on the FX processors as with the Phenom II/Athlon II lines, but some mainboards will circumvent their block and likely allow the full core count to be used anyway.

Retail FX processors will ship with a standard AMD heatsink and fan in the box, and in select markets will be bundled with an all-in-one liquid cooling system. FX is for enthusiasts and, in the immortal words of AMD's John Taylor, 'for the users who know what the hell they are doing'.

So how does it compare to the competition? We've got a healthy bump in performance, matching Sandy Bridge in a lot of ways, a real win some/lose some. Intel wins the integer heavy race, AMD wins the 128-bit floating point but not the 256-bit fight; not much change there, except how much AMD has gained on Intel on the integer side. Priced against the Intel Core i5 2500K, it's a real fight and shows AMD's marketing smarts - the difference between 2500K and 2600K is minimal in the real world and apparently most users are buying the cheaper processor.

Intel. Visibly Smart...

Does it matter that the fight is a four core 95W CPU with SMT vs. a 125W CPU with pseudo-CMT? The TDP is not irrelevant here, as the extra power the bulldozer uses to deliver the same performance is going to be felt somewhere, but it's not a consideration for the overclocking enthusiasts who want the most performance at the expense of everything else. As an improvement over the last generation, it's a great step up and the high performance GPUs AMD have been putting out there finally get CPU brethren to match, and the high end GPUs use up a lot more power budget than ever before, which does put a focus back on how many watts the CPU is sucking down to power it. AMD has some work to do for the future, with Ivy Bridge due in 2012 and a possible 20-30% performance improvement at lower power.

It's a point in AMD's favor that there is a decent amount of socket interoperability between AM3 processors and AM3+ mainboards. The mainboard partners are doing a lot to improve that and give broader AM3+ CPU support on their existing products, much to their credit. We only hope that AMD continues this trend, and don't end up in some ridiculous situation where they not only break socket compatibility with previous generations but also use incompatible products in the same socket and the same name. That would be not awesome, in fact the opposite. Hopefully we'll get a hint soon that the next generation of FX processors and platform will continue the AMD tradition of affordable upgrades and piecemeal transitions.

In summary, AMD has brought the fight back to Intel and are competitive again, both in features and in value. They don't win the vaunted performance/watt crown, on the desktop at least, but they do have a serious platform option for you to consider when building your next enthusiast desktop. The big problem, and one that Intel faces too, is that we're still at parity with the first generation Core i-series. If you're on an X58 platform, you've not had a really compelling reason to spend on a new CPU and mobo for an upgrade yet, unless you need the new instructions inside Sandy Bridge or Bulldozer - and those aren't hitting many games we know of. If you're on recent AMD platform (AM3), the simpler piecemeal upgrade path will likely be very attractive to you if you can't invest in all new kit at once. FX is not a Sandy Bridge killer, nor is it killed by Sandy Bridge - they're both horned, winged beasts. The success of FX is likely to be down to availability, and AMD's recent woes with GlobalFoundries 32nm SOI process don't look to be helping in that regard.

Verdict? It's tempting to be disappointed and doom'n'gloom about FX's performance. The clean kill and win isn't here against Intel's top Sandy Bridge. But, AMD hasn't priced it against the 2600K, it's head to head with the 2500K, and in that context AMD's Scorpius platform is a solid buy. AMD's FX processor is enough to challenge Intel in a lot of areas, but AMD still has work to do on improving performance while they live in an x86 and low-thread count integer based workload world. The first generation Bulldozer's have slimmed down the 'big cores' as part of their ongoing strategy for shifting to APUs, and this has obvious consequences for performance. Despite that, there is a very real and impressive boost in performance for current real world applications vs. the previous generation. Well done, AMD.

'Sketchy Duel' by Ant Blades; used here as a metaphor for AMD vs. Intel