DUAL CPU board vs 2 Single CPU boards - 1Us

[alvin at Maggie.Linux-Consulting.com]

hi ya

adding my twists/comments... please ignore if ya so desire :-0

2 complete boxes is better ???
	- if one system dies... the other keep cranking along

	- if maintenance is done right... maintaining 5 or 100 servers
	should NOT make any difference .. everything automated


dual cpu system
	- if the power supply dies...both cpu's is dead
	- the cpu have to share memory/disks/ethernet to do its local work
	- if the disk dies...both cpu sits idle

systems typically die due to (cheap) fans dying...

am assuming the same overhead for network traffic between servers ...

performance between single and dual-cpu systems can be different
depending on can the tasks be divided into nice pieces for each server
	vs divided between 2 CPUs on the same motherboard


- midtower/full tower atx case is super cheap ( $25 - $100 range )
- 4U chasis is cheap
- 2U/3U chasis is about $50 more
- 1U chassis is about $250 - $300 --- 
  - cheap 1U cases at $150 range...
  ( do it yourselef is $100 or less?  but you spend lots of time with
  ( wires, led, screws, heatsinks,..etc..etc..


Jim's comparason between two systems at $505 vs $1023 for dual looks
good for network booted diskless machines
	- i too would like to see some benchmarks for these 
	performance comparsons ...

But if you have a disk-based system...
	than there is some differences in minor costs differences 
	between 2 systems vs one dual-cpu system


Buildable/tested AMD 1U system
------------------------------
$ 250	C1400 14" deep 1U
$ 125	Asus A7S w/ onboard NIC w/ onboard SVGA
$ 150	AMD 1.4G XP ( 1700+ ) 
$ 160	512MB DDR PC2100
$ 250	Maxtor 120GB disks
$  75	5x extra fans
-----	------------------
$1010	parts-off-the-shelf

$2020  	for two of um .... more expensive than one dual-cpu system ...:-)


Dual CPUs
------------------
$ 250	C1400 14" deep 1U
$ 250	(generic) Tyan dual-cpu mb  - can go to $500 mb too
$ 400	2x AMD 1.4G MP ( 1600+ )
$ 160	512MB ddr pc2100
$ 250	maxtor 120GB
$  75	5x extra fans
-----	-------------
$1385	Dual cpu system off the shelf


have fun
alvin
http://www.linux-1u.net


On Thu, 7 Mar 2002, Jim Fraser wrote:

> 
> Robert,
> 
> You bias the calculation a bit with the selection of your hardware...if you
> use inexpensive COTS..we are talking something like 50 per case not
> 350...also a decent mother board with NIC can be had for 150 and you   need
> to look at the difference between XP and MP proc costs currently a
> difference of 90 bucks per cpu on pricewatch.  I think if you re-evaluate
> your calcs based on that you get something like:
> 
> 
>                      Single            DUAL
> MB (w/NIC)            150                220
> CPU (1900)            180                239 X 2
> case                   50                 75 (50+ 25 some super PS and
> cooling)
> memory(512DDR)        125               125 *2
>                    _________            __________
>                      505                1023
>                       X2
>                      1010      vs       1023
> 
> As far as I see it is awash price wise.  Most dual CPU AMD setups I have
> seen in rack mounts exceed $2000 easy as they require exotic cooling
> measures.  On the other hand, there will be some cost penalty associated
> with switch costs having more single CPU's.
> 
> I agree with your response to the application and effective throughput and I
> think you have to run your program before you actually know how it will
> perform on these things...looking at benchmarks can be very misleading.
> 
> I have not seen any benchmarks on the dual AMD setups comparing them to
> singles, have you?
> 
> That was quite response you posted!
> 
> Thanks
> 
> Jim
>