[Wien] 2 XEON 5355 or 4 XEON 5150?

[Alexander Shaposhnikov]

Hello Florent,

On Monday 22 October 2007 15:35, Florent Boucher wrote:
> Dear Wien users,
***
> In that case, if you look the benchmark results below, it is not a good
> solution !
>
> bi-Xeon 5320 (overcl 2.67GHz)   
******
> You can see that even an overclocked solution run slower than an AMD
> when putting 8 jobs on it !
> The memory band width is much lower than on AMD, due to the memory
> architecture. It is better in that case to by more nodes with less
> expensive AMD chips for which the efficiency is much better when the
> load average is close to 100%.

I believe those are results i obtained for my machine :)
The scaling is very bad indeed, even though the machine has almost 20% faster 
memory than standart non-overclocked bi-Xeon X5355 (and the same CPU 
frequency)

> For information, we have been able to buy a solution with 20 nodes from
> a well known company (1U, 2 x AMD 2.8GHz bicore, 8Go DDR2 per node,
> Infinipath DDR 4X, warranty 3 years) for less than 50k€ (without taxes).
> The power consumption for such a configuration will be less than 7kW/h.

You could have done better and pay less.
Typical 24-port infiniband switch is 5k€, 1 node based around Intel Q6600 with 
8GB memory is 1k€ including infiniband mem-free network card, so 24k€ for 24 
nodes, 30k€ total. 
The cluster will have 920Gigaflops, and consume no more than 5KW.
And if you dare :) , you can always trouble-free overclock it to at least 
3GHz, increasing to 1.15 Teraflops.
Scaling will be good enough, as the memory performance of Intel desktop 
chipsets is adequate. 

Best Regards.