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AMD's Bulldozer server benchmarks are here, and they're a catastrophe

arstechnica.com

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Re: AMD's Bulldozer server benchmarks are here, and they're a catastrophe

#21

Post by lucian1900 »

zdw wrote: post #3

AMD's problem is that they can't compete either in the low power high performance (the 45w and under laptop chips), or high power high performance markets (like the high end Xeons). So they build massively parallel chips, and try new stuff like the Bulldozer platform, which creates a bunch of trade offs. It's very similar in concept to the Sun/Oracle Sparc T-series, with lots of great performing integer cores, and (a…

I would say the have the best you can get on the market for low power, high performance with the Fusion chips. I have one in my Thinkpad and it has great CPU performance, excellent GPU performance and the battery lasts 7h.

Re: AMD's Bulldozer server benchmarks are here, and they're a catastrophe

#22

Post by gjm11 »

bad_user wrote: post #14
zdw wrote: post #3

AMD's problem is that they can't compete either in the low power high performance (the 45w and under laptop chips), or high power high performance markets (like the high end Xeons). So they build massively parallel chips, and try new stuff like the Bulldozer platform, which creates a bunch of trade offs. It's very similar in concept to the Sun/Oracle Sparc T-series, with lots of great performing integer cores, and (a…

They did the same thing back in the days of AMD K6 ... fast integer ops, poor floating point. Then AMD Athlon came, built on the same foundation and Intel never knew what hit them. Don't dismiss Bulldozer just yet. AMD has this uncanny ability to make short term compromises that benefit them in the long term.

I worry that you're saying they have "this uncanny ability" on the basis of one instance where they've done it. The other possibility would be that they just got lucky once (helped by Intel's terrible, horrible, no good, very bad P4 design) and haven't had similar luck success before or since.

Re: AMD's Bulldozer server benchmarks are here, and they're a catastrophe

#23

Post by DrPizza »

dman wrote: post #20
DrPizza wrote: post #12

Earlier quoted context omitted.

> This article is impressively bad. Cheers! > While the 8-module chip does share a few things (mainly a vector processing unit, that becomes two when doing the 128-bit SSE operations) A few things? No, it shares a lot of things. The entire floating point and SIMD unit. The entire front-end. The branch predictor is, I believe, a weird hybrid of shared and non-shared. The I-cache, and the L2 cache, also both shared. Th…

Benchmarks at http://www.phoronix.com/scan.php?page=article&item=amd_f... appear to paint a picture of a much more balanced performance profile for bulldozer chips. It does well in threaded applications and where code is recompiled for it. I cringed a bit when I saw this on arstechnica - the linkbaitey headline, the image of a burning bulldozer, the lack of any benchmarks that you ran yourself and the fact that data…

The Phoronix benchmarks, like most others, suggest that the only area where Bulldozer appears at all competent is HPC. To describe this as niche is an understatement.

a) I agree it remains unclear how much difference the SSD makes. That's why I don't think it's a useful demonstration of Bulldozer's performance _even though AMD is citing it as such_. b) Yes, I do. That 1/3 more cores gives 1/3 more performance in a test that scales almost perfectly means that the per-core performance has stood still. A 32 nm K10.5 chip with 1/3 more cores would perform just as well, cost less to build, use less power, and eliminate the performance regressions. So what is the point of Bulldozer? c) No, it reinforces the "Bulldozer performs no better than a scaled up K10.5 system would and hence is pointless" narrative. d) @_@ e) No. I don't have a half million dollars of equipment just lying around so that I can run TPC-C (etc.) myself.

Re: AMD's Bulldozer server benchmarks are here, and they're a catastrophe

#24

Post by dman »

DrPizza wrote: post #23
dman wrote: post #20

Earlier quoted context omitted.

Benchmarks at http://www.phoronix.com/scan.php?page=article&item=amd_f... appear to paint a picture of a much more balanced performance profile for bulldozer chips. It does well in threaded applications and where code is recompiled for it. I cringed a bit when I saw this on arstechnica - the linkbaitey headline, the image of a burning bulldozer, the lack of any benchmarks that you ran yourself and the fact that data…

The Phoronix benchmarks, like most others, suggest that the only area where Bulldozer appears at all competent is HPC. To describe this as niche is an understatement. a) I agree it remains unclear how much difference the SSD makes. That's why I don't think it's a useful demonstration of Bulldozer's performance _even though AMD is citing it as such_. b) Yes, I do. That 1/3 more cores gives 1/3 more performance in a te…

My reading of the phoronix article suggests that Bulldozer does fairly well on the following tests. a) ffmpeg encoding b) parallel io c) x264 encoding d) compression e) mp3 encoding f) c-ray rendering g) smallpt

I will concede that I know virtually nothing of which workloads are representative of what percentage of the market.

Re: AMD's Bulldozer server benchmarks are here, and they're a catastrophe

#25

Post by iFire »

Jach wrote: post #8
iFire wrote: post #7

Who here wants to play with 64 cores? That's 4 sockets of Opteron 6272 which is around 540 dollars each on newegg.

How about 144? ;P http://www.greenarraychips.com/home/products/index.html

DB003 Evaluation Board Reference for EVB001 seems to have low interconnect bandwidth.

I don't see anything like hypertransport.

Re: AMD's Bulldozer server benchmarks are here, and they're a catastrophe

#26

Post by DrPizza »

dman wrote: post #24
DrPizza wrote: post #23

Earlier quoted context omitted.

The Phoronix benchmarks, like most others, suggest that the only area where Bulldozer appears at all competent is HPC. To describe this as niche is an understatement. a) I agree it remains unclear how much difference the SSD makes. That's why I don't think it's a useful demonstration of Bulldozer's performance _even though AMD is citing it as such_. b) Yes, I do. That 1/3 more cores gives 1/3 more performance in a te…

My reading of the phoronix article suggests that Bulldozer does fairly well on the following tests. a) ffmpeg encoding b) parallel io c) x264 encoding d) compression e) mp3 encoding f) c-ray rendering g) smallpt I will concede that I know virtually nothing of which workloads are representative of what percentage of the market.

I don't think most server systems are doing much in the way of MP3 or H.264 encoding.

Rendering is more or less equivalent to HPC. Different markets, but similar problem sets (lots of computation, minimal communication or dependencies between threads).

None of those are particularly relevant to typical server workloads; servers are doing things like querying databases, spitting out Web pages, running Java VMs, running virtualization software, that kind of thing.

Re: AMD's Bulldozer server benchmarks are here, and they're a catastrophe

#27

Post by onenine »

DarkShikari wrote: post #18
onenine wrote: post #11

Earlier quoted context omitted.

I'm not sure what it would look like in the video [d]ecoder world, but I don't think that would matter since most the time you'd want to use the 256-bit vector instructions (in practice this would hardly be a high priority until they're nearly ubiquitous...). For use cases where you are addressing large memory regions this hardly seems like that big of a deal. There are times when you can schedule tons of calculation…

since most the time you'd want to use the 256-bit vector instructions There are no 256-bit integer vector instructions on x86, and AVX is slower than SSE on Bulldozer.

Sad but true...You can issue SIMD instructions on 4 doubles at once though (and put whatever you want in those 16 registers)....

Re: AMD's Bulldozer server benchmarks are here, and they're a catastrophe

#28

Post by onenine »

DrPizza wrote: post #12
onenine wrote: post #9

This article is impressively bad. While the 8-module chip does share a few things (mainly a vector processing unit, that becomes two when doing the 128-bit SSE operations) they really can run 16 threads on 16 ALUs. But, they'll have sse contention if they schedule more than 8 256-bit vector operations (sadly intel won't bring this instruction set to market for a bit). Bulldozer is pretty cool, but sadly the tech pres…

> This article is impressively bad. Cheers! > While the 8-module chip does share a few things (mainly a vector processing unit, that becomes two when doing the 128-bit SSE operations) A few things? No, it shares a lot of things. The entire floating point and SIMD unit. The entire front-end. The branch predictor is, I believe, a weird hybrid of shared and non-shared. The I-cache, and the L2 cache, also both shared. Th…

Thanks for the reply but your piece wasn't balanced and well below the quality standards I used to hold for your site (always re-balance expectations!). You didn't talk about power consumption or anything interesting about the platform. We can get press releases from intel.

Re: AMD's Bulldozer server benchmarks are here, and they're a catastrophe

#29

Post by DrPizza »

onenine wrote: post #28
DrPizza wrote: post #12

Earlier quoted context omitted.

> This article is impressively bad. Cheers! > While the 8-module chip does share a few things (mainly a vector processing unit, that becomes two when doing the 128-bit SSE operations) A few things? No, it shares a lot of things. The entire floating point and SIMD unit. The entire front-end. The branch predictor is, I believe, a weird hybrid of shared and non-shared. The I-cache, and the L2 cache, also both shared. Th…

Thanks for the reply but your piece wasn't balanced and well below the quality standards I used to hold for your site (always re-balance expectations!). You didn't talk about power consumption or anything interesting about the platform. We can get press releases from intel.

What is there that is "interesting" about the platform?

Power consumption was mentioned at a number of points in the article. It's just there's not a whole lot to say about it--it's not exactly a strength of the architecture.

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