Ex-AMD Engineer Reveals Why Bulldozer Design Is Inferior To Intel’s Sandy Bridge

AMD's recently launched eight-core Bulldozer processors didn't live up to pre-launch expectations, as it barely managed to outperform Intel's current offering of quad-core Core i7 CPUs. The likely reason behind, a former AMD engineer revealed, is over-relying on automated design tools that design less efficient chips than human engineers.

According to Cliff A. Maier, an AMD engineer who left the company few years ago, AMD has abandoned the practice of hand-crafting performance-critical parts of its chips shortly after acquiring ATI.

"The management decided there should be such cross-engineering [between AMD and ATI teams within the company], which meant we had to stop hand-crafting our CPU designs and switch to an SoC [System on Chip] design style. This results in giving up a lot of performance, chip area, and efficiency. The reason DEC Alphas were always much faster than anything else is they designed each transistor by hand. Intel and AMD had always done so at least for the critical parts of the chip. That changed before I left - they started to rely on synthesis tools, automatic place and route tools, etc.," he said.

Based on his experience, Maier believes that automated design tools produce designs that are 20% bigger and 20% slower, mainly due to the increase in number of transistors which results in increasing die size, increasing cost and reducing efficiency.

"I had been in charge of our design flow in the years before I left, and I had tested these tools by asking the companies who sold them to design blocks (adders, multipliers, etc.) using their tools. I let them take as long as they wanted. They always came back to me with designs that were 20% bigger, and 20% slower than our hand-crafted designs, and which suffered from electro-migration and other problems," Maier reminisced.

AMD sells its eight-core FX series processors (315mm2 die size) for $245 in 1000-unit quantities, while Intel sells its hand-crafted Core i-series "Sandy Bridge" quad-core chips (216mm2 die size) for $317 in 1000-unit quantities. Both processors employ 32nm transistors so they have comparable prices per mm2 of die, meaning that Intel's CPUs are sold at a much higher profit margin than AMD's.

Add new comment

CAPTCHA
This question is for testing whether you are a human visitor and to prevent automated spam submissions.

Comments

I7 vs Bulldozer

At the time Athlon X2 chips beat the intel core 2 duos and quads hands down. Then Intel released the I7 which smashed all the AMD chips to bits. I expected bulldozer to be far advanced, yet I am sitting in front of a bulldoxer 8 core and an I7 920 from 2008 (Overclocked to 3.2Ghz) and the I7 beats the bulldozer in every way. I'm so dissapointed with the bulldozer, even though it was a bit cheaper than an I7, so what, I wanted a performance chip, otherwise I would have bought an I5 or I3

GoogleGod

I know what they mean by that handcrafting, try validate HTML code and you will get about 20% more speed. Well the point is, data is ready for use and don't wait for do to process, i see it's about the same in CPU world.

Bang for buck?

Intel i7 Sandybridges are still more expensive. And Automated systems are always constantly on the improving side, a few years ago it may be 20% slower and 20% bigger, but it wont be the same right now.

That's just wishful thinking.

That's just wishful thinking. Bulldozer doesn't compete with the Core i7 in performance but with the i5 which is cheaper. The Core i5 has about the same overclocking potential as the bulldozer, and this is at lower power consumption which means less heat generation. It is also faster per MHz (better IPC) which means that if you overclock both processors the Core i5 will outperform Bulldozer when both processors are running at for instance 4.5 GHz.

Automated systems aside, the bulldozer has too much cache memory, it's too big and too slow while taking up the majority of die space. What little die space you have left is split between 8 small and slow cores, it's a stupid design. Compare this with the i5 which has 4 cores and less but faster cache on the same manufacturing process (32nm). Simple logic states that these cores have bigger transistor budget thus more raw performance even if the die area of the bulldozer is bigger. Which also translates into more power consumption.

AMD needs to get their shit together because the last thing we need is Intel with complete monopoly.

lol

AMD sucks and always will. they just release this cpu to try and compete with a leading company. what do you think is going to happen when intel releases the lga2011 cpu's. people are going to say whats AMD!. lol i would not even take the time to hit amd bulldozer with a hammer.

lol

AMD sucks and always will. they just release this cpu to try and compete with a leading company. what do you think is going to happen when intel releases the lga2011 cpu's. people are going to say whats AMD!. lol i would not even take the time to hit amd bulldozer with a hammer.

Really?

Don't agree, AMD where making a lot of progress 5 years ago. The Phenom X6's for the price are excellent, I was currently in the market and was going to go Intel again. Upgrading from an E2180 and the X6 1090T BE (Cost £109) just smacked around the I3 3.4Ghz (Also £110) like it was a feather.

The FX may be a let down but it's not the end of the world.

Add new comment