AMD Bulldozer Debunked (and Benchmarked)
Last Updated on Wednesday, 26 October 2011 10:26 Written by Nick McD Thursday, 27 October 2011 01:00
AMD’s latest offering has left fans depressed, as Intel is still the king of the benchmark. Or are they? With the 8 core Bulldozer Zambezi chips up to the FX 8150 in final production and on the market, more benchmarks under widely varying conditions are showing that is monster processor continues to lose, sometimes narrowly, sometimes widely, to Intel’s Sandy Bridge, and then to suddenly dominate in yet another benchmarking task. Variances like that tell us one thing: we don’t understand the processor to properly compare it to the competition.
AMD is not the dominant processor manufacturer, but neither are they one to pass off as lacking innovation, and this turns out to be the case with the whole Bulldozer issue. The bus architecture, shared caches, independent clocking, and Turbo Core are all things we have seen previously in the Phenom and Phenom II, but most often in a less than full-fledged form. Yes, geeks of the world, AMD has been beta testing on us! More after the break…
This isn’t a surprise, as with tech you don’t ever get it right the first time. For instance the shared caching on the first X4 chips was a disaster, slowing memory retrieval from the previous X2 series and making the Intel Core2 series far more appealing. The first Turbo Core was so restrictive that the chips were hesitant to even turn it on, and when they did it snapped off so quick there was hardly any performance improvement because the chip was so dumb it couldn’t properly calculate its power load on the fly. But AMD was the first to try it, and Intel soon followed with their own refined version.
The Bulldozer is the first chip from AMD that properly integrates all of these features and does it well, and is potentially ahead of Intel in the course of development. So why are the Sandy Bridge CPUs still winning? Simple answer: AMD is ahead of the operating systems and applications, too.
Bulldozer is that different, that in fact it was never engineered for branching simple threading as most of the world’s software is written to be. Windows 7 sees 8 cores, and essentially it then randomly assigns tasks to whatever core is free at the time, but this results in so much cache movement it slows down the memory bus. And this is likely why Intel has been largely ignoring the Bulldozer concept aside from future designs, as they see no reason to compete in an arena where there is no way to properly take the upper hand, because the software just isn’t there.
AMD is suffering in the ultra-geek market, as too few people seem to understand what is holding this monster back from being the performance beast we all crave. Yet benchmarkers have already found that simple memory-intensive multithreading tasks, like large compression under 7-Zip and (yes, I’ve been preaching it) H.264 MPEG4 video encoding take off with as much as a 5% lead between the AMD FX 8150 and the Intel i7 2600K core-to-core. Where branching is not needed, and heavy thread computing is desired, the structure shows itself.
Windows 8 is already showing that it will be the desired platform for large multi-core processors, because in fact the four- and six-core CPUs from both Intel and AMD are honestly not being tasked properly, and the Bulldozers complexity with its levels and layers of cache are simply illustrating this fact. Windows 8 is far more adept in addressing thread pairings and cache placements, and doesn’t require the massive memory swapping that is killing the X8 now.
Unfortunately, Windows 8 isn’t expected to launch until late 2012, and by then we will be seeing the second phase of the Bulldozer, the Piledriver, as well as Intel’s next generation core, the Ivy Bridge, so the world will be a different place by then in terms of microarchitecture. Windows 7 likely will see another enhancement or service pack in that time somewhat enhancing it for multicore operation, but for the die-hard computer wizards, expect an enhancement in the next release or two of the Linux kernel to really show the processing capabilities.
- Is AMD’s Bulldozer a success? (zdnet.com)
- Feature: Can AMD survive Bulldozer’s disappointing debut? (arstechnica.com)