The Bulldozer Review: AMD FX-8150 Tested
by Anand Lal Shimpi on October 12, 2011 1:27 AM ESTThe Impact of Bulldozer's Pipeline
With a new branch prediction architecture and an unknown, but presumably significantly deeper pipline, I was eager to find out just how much of a burden AMD's quest for frequency had placed on Bulldozer. To do so I turned to the trusty N-Queens solver, now baked into the AIDA64 benchmark suite.
The N-Queens problem is simple. On an N x N chessboard, how do you place N queens so they cannot attack one another? Solving the problem is incredibly branch intensive, and as a result it serves as a great measure of the impact of a deeper pipeline.
The AIDA64 implementation of the N-Queens algorithm is heavily threaded, but I wanted to first get a look at single-core performance so I disabled all but a single integer/fp core on Bulldozer, as well as the competing processors. I also looked at constant frequency as well as turbo enabled speeds:
Unfortunately things don't look good. Even with turbo enabled, the 3.6GHz Bulldozer part needs another 25% higher frequency to equal a 3.6GHz Phenom II X4. Even a 3.3GHz Phenom II X6 does better here. Without being fully aware of the optimizations at work in AIDA64 I wouldn't put too much focus on Sandy Bridge's performance here, but Intel is widely known for focusing on branch prediction performance.
If we let the N-Queens benchmark scale to all available threads, the performance issues are easily masked by throwing more threads at the problem:
However it is quite clear that for single or lightly threaded operations that are branch heavy, Bulldozer will be in for a fight.
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Saxie81 - Wednesday, October 12, 2011 - link
Ouch.... Not looking good. :SThanks for the reply, again great review!!
velis - Wednesday, October 12, 2011 - link
Ignoring the power consumption it seems to me that @4.6GHz it should start being quite competitive.So can we expect base clocks to rise once significant volume of these chips starts getting out and GloFo refines the process?
I also must admit I didn't expect 2 bn transistors. All the time AMD was bragging about how much they saved and then we get this behemoth. No wonder they have process issues. Such big chips always do.
cfaalm - Wednesday, October 12, 2011 - link
Well it is an 8-core, not a 4 core. 2x 995M (Sandybridge 4C) almost 2B, though I am sure the multply isn't exactly correct. A lot of it depens on the L3/L2 RAM amounts. The savings seem to be minimal.I am still confused about why they so deliberately chose to go with a relatively low single thread performance. My main application is multithreaded, but since it's such a mixed bag overall I am pretty unsure if this will be my next CPU, unless I get to see convincing Cubase 6 benchies. For an FX moniker it needs to perform better than this anyway.
I'll throw in a lyric from The Fixx
"It doesn't mean much now, it's built for the future."
TekDemon - Wednesday, October 12, 2011 - link
Wow, no wonder they say you need water cooling or better to go 5Ghz+.enterco - Wednesday, October 12, 2011 - link
AMD should send a developer team to CryTek to help them release a patch able to use more cores :)medi01 - Wednesday, October 12, 2011 - link
Uhm, what about other numbers?IlllI - Wednesday, October 12, 2011 - link
this might be the final nail in the coffin. We might have to wait longer for it to be competitive? People have literally been waiting for -years- for amd to catch up.probably by the time piledriver(or whatever it'll be called) comes out, ib will be out (and even further behind intel)
btw I think tomshardware tested it with windows 8 and it was still a turd.
I seriously hope you can get some answers/reasons why amd released such a woeful product. Maybe this was why dirk was fired? All I know is after 7+ years of amd, my next processor will be intel
Ushio01 - Wednesday, October 12, 2011 - link
Desktop CPU's are Halo parts and as such are irrelevant. It's the Server and OEM Laptop CPU's were AMD needs to perform and AMD's server share just keeps dropping.lyeoh - Wednesday, October 12, 2011 - link
Thing is I wouldn't want to use them in my servers: http://us.generation-nt.com/answer/patch-x86-amd-c...FWIW when the Athlon64s first came out, we bought a bunch of them, they were not bad, but there were clock issues - the TSCs weren't synchronized. So had to set idle=poll (and thus using more watts).
You can blame the OS developers, but most people buy new hardware to run existing operating systems and programs on, not future unreleased ones.
It sure is looking bad for them. I won't be buying AMD CPUs but I hope the fanboys keep them alive ;).
OCedHrt - Wednesday, October 12, 2011 - link
"Other than the 8150, only the quad-core FX processors are able to exceed the 3.3GHz clock speed of the Phenom II X6 1100T."The 6 core FX is also clocked higher?