The Bulldozer Review: AMD FX-8150 Tested
by Anand Lal Shimpi on October 12, 2011 1:27 AM ESTCache and Memory Performance
I mentioned earlier that cache latencies are higher in order to accommodate the larger caches (8MB L2 + 8MB L3) as well as the high frequency design. We turned to our old friend cachemem to measure these latencies in clocks:
| Cache/Memory Latency Comparison | ||||||
| L1 | L2 | L3 | Main Memory | |||
| AMD FX-8150 (3.6GHz) | 4 | 21 | 65 | 195 | ||
| AMD Phenom II X4 975 BE (3.6GHz) | 3 | 15 | 59 | 182 | ||
| AMD Phenom II X6 1100T (3.3GHz) | 3 | 14 | 55 | 157 | ||
| Intel Core i5 2500K (3.3GHz) | 4 | 11 | 25 | 148 | ||
Cache latencies are up significantly across the board, which is to be expected given the increase in pipeline depth as well as cache size. But is Bulldozer able to overcome the increase through higher clocks? To find out we have to convert latency in clocks to latency in nanoseconds:
We disable turbo in order to get predictable clock speeds, which lets us accurately calculate memory latency in ns. The FX-8150 at 3.6GHz has a longer trip down memory lane than its predecessor, also at 3.6GHz. The higher latency caches play a role in this as they are necessary to help drive AMD's frequency up. What happens if we turn turbo on and peg the FX-8150 at 3.9GHz? Memory latency goes down. Bulldozer still isn't able to get to main memory as quickly as Sandy Bridge, but thanks to Turbo Core it's able to do so better than the outgoing Phenom II.
L3 access latency is effectively a wash compared to the Phenom II thanks to the higher clock speeds enabled by Turbo Core. Latencies haven't really improved though, and Bulldozer has a long way to go before it reaches Sandy Bridge access latencies.
Facebook
Twitter
RSS
430 Comments
View All Comments
Shuxclams - Wednesday, October 12, 2011 - link
Wow... I mean what else do you say? Intel is walking away from the competition, and thats sucks for everyone long term. FAILezinner - Wednesday, October 12, 2011 - link
AMD, please up your game. Stop being just the lower price point and become the leader. We do not need 10 to 20 processors to choose from. Let's have less products and better performance, even if the price is the same or more than Intel. I like that you stick with the socket longer than Intel, but you keep getting beat everytime. AMD needs new people who can drive them further ahead.BlueFlash - Wednesday, October 12, 2011 - link
New architectures always require software optimization to shine. Will enough Bulldozers sell to convince major software vendors to do that work? Could we get some AMD optimized benchmarks? In any case, I prefer the APU strategy, given my compute needs.Chaser - Wednesday, October 12, 2011 - link
I invested in AMD last a while back and like many on here thought that BD was going to restore AMD's prominence as the enthusiast's definitive choice once again. Thankfully, especially now, I pulled out my money when it was still safe and also decided to not wait for my next upgrade rig and thankfully (now) I went Z68, I7 2500K and GTX 580.Maybe my hopes for AMD CPU wise was a pipe-dream. It just seems that INTEL is so far ahead of them now with their rather aggressive development that AMD is destined to be the bargain basement alternative forever. Regardless of my lack of realism or false hopes I suppose, its still a downer.
bji - Wednesday, October 12, 2011 - link
At a certain point in the not too distant future, the x86 market will be stagnant enough in terms of sales growth (with mobile devices taking larger and larger shares of the computing market) that it will not pay to spend the exponentially increasing R & D dollars to advance x86 state of the art. At that point, AMD will have an opportunity to catch up to Intel - if AMD survives in the x86 market long enough.FunBunny2 - Wednesday, October 12, 2011 - link
Always remember: no one, that's *no one* not even Intel, runs X86 instruction set in hardware. No one. All these X86 cpus emulate is instruction set through a RISC core. It's only a matter of time until nobody bothers with the emulation.Mishera - Wednesday, October 12, 2011 - link
Let me try to paint a glass half full picture:Amd's CPU division had to have known that the performance of this architecture for years now... So I imagine that this might not be just a "Let's just get something out there" move. So maybe there's some alternative ways of looking at this:
1. Amd has made it clear that this is the beginning of what they really mean by APU and there will be more architecture movement towards that end in the future. Could this be a transistion CPU to a possibly very different x86 future?
This may not be just what AMD is planning to do on it's own. There have been rumors of a possible Arm partnership.
http://semiaccurate.com/2011/06/22/amd-and-arm-joi...
Could it be that this chip has a better set up than phenom for an interchangeable modular structure?
2. With desktop pcs in decline could this be a move to capture more server space, which is still a growing market?
3. This obviously also begs the question is there some benefit of this design with a gpu attached?
4. Is there some benefit for mobile computing?(starting to stretch here...)
I don't know. I don't want to think this is just an epic fail but...
This is kind of sad since I was betting they'd be 3/3 but on the really big one the shot out a dud.
fic2 - Wednesday, October 12, 2011 - link
Kind of wondering about #3.Let the wait for Trinity begin. Hopefully the changes from Bulldozer->Piledriver help more than is expected.
If the FM1 platform wasn't dead I would think about getting a Llano desktop for my nephew but I think he'll just have to wait. Maybe if FM2 mb start coming out and Llano can drop in with a possible change to Trinity later.
Mishera - Thursday, October 13, 2011 - link
Yeah, I think I meant #3 to be part of #4. I cant help but to think that is bulldozer performs poorly in a trinity package that's very bad news for Amd, even if this performs well in servers..I am left wondering how much of bulldozer as an architecture is an evolutionary step to the future they've described. I think that's much more important than the performance we see today. Perhaps this could in that respect be a Fermi and not so much Pentium 4.
tipoo - Wednesday, October 12, 2011 - link
Their own last generation 6 core Thuban beats this in half the tasks. If you have an application that effectively uses 8 threads, this might be a worthy upgrade, but anything lightly threaded is pretty bad (looking at the real world benchmarks, Techreport, Anandtech, Tomshardware, etc). I had high hopes for this.They did say though that Windows 8 would make better use of modules (vs cores) and will know what to do with them better, and to expect another 10% increase from that. But we're still at a point where an AMD core doesn't even beat out a Nehalem core, let alone a Sandy Bridge or Ivy Bridge.
*Le Sigh*
This Bulldozer is more of a Mudshovel. Their goal of 15% single threaded performance increase per core per year won't have them catching up to Intel anytime soon either.
Well, the optimist in me says the L3 cache-less higher clocked quad core mainstream parts will be more competitive. And cheap too, the 6 core FX is only 169.