ATHLON vs XEON: number crunching

[Ivan Oleynik]

Hi Steffen,

Looking at your numbers I can make a conclusion that loading 2 processors
on Xeon simply slows down the stream as for Athlon it does not and they
are quite close to each other in case of full load of the node. Are you
saying that the real test would be to run TWO IDENTICAL codes on the same
node to load both processors?

Ivan

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On Thu, 20 Jun 2002, Steffen Persvold wrote:

> 
> Well, the E7500 chipset has two DDR _channels_ while the AMD762 system 
> controller has one DDR _channel_. One DDR channel is 64bit + ECC and is 
> normally running at 133MHz which gives us a theoretical peak performance 
> of 2.1 GBytes/sec per channel. However, the E7500 chipset is only able to 
> run the memory bus at 100MHz and with the interleaving of the two channels 
> that gives us a theoretical peak performance of 3.2 GBytes/sec.
> 
> I believe the term "banks" is related to the layout of the DIMMs and has 
> nothing to do with the architecture of the system controller. 
> 
> Here are some stream numbers. The Athlon platform is Tyan S2466 equipped 
> with two Athlon MP 1900+ (1.6 GHz), and the Xeon platform is SuperMicro 
> P4DPR-6GM+ equipped with two Xeon 1.8 GHz (Prestonia).
> 
> Athlon, 1 process :
> 
> Function     Rate (MB/s)  Avg time   Min time  Max time
> Copy:        877.5785      0.0365      0.0365      0.0367
> Scale:       801.7857      0.0400      0.0399      0.0402
> Add:         894.9042      0.0537      0.0536      0.0539
> Triad:       887.2120      0.0542      0.0541      0.0544
> 
> Athlon, 2 processes :
> 
> Function     Rate (MB/s)  Avg time   Min time  Max time
> Copy:       1385.1016      0.0236      0.0231      0.0253
> Scale:      1345.9527      0.0242      0.0238      0.0250
> Add:        1168.2247      0.0419      0.0411      0.0425
> Triad:      1210.0117      0.0405      0.0397      0.0473
> 
> 
> Xeon, 1 process :
> 
> Function     Rate (MB/s)  Avg time   Min time  Max time
> Copy:       1898.8954      0.0170      0.0169      0.0181
> Scale:      1813.9614      0.0179      0.0176      0.0186
> Add:        1839.8592      0.0265      0.0261      0.0274
> Triad:      1826.2738      0.0266      0.0263      0.0274
> 
> Xeon, 2 processes :
> 
> Function     Rate (MB/s)  Avg time   Min time  Max time
> Copy:       1160.5962      0.0297      0.0276      0.0311
> Scale:      1261.8243      0.0269      0.0254      0.0275
> Add:        1237.7180      0.0395      0.0388      0.0407
> Triad:      1231.9053      0.0398      0.0390      0.0405
> 
> 
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Ivan I. Oleynik                       E-mail : oleynik at chuma.cas.usf.edu
Department of Physics
University of South Florida
4202 East Fowler Avenue                  Tel : (813) 974-8186
Tampa, Florida 33620-5700                Fax : (813) 974-5813
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