Edward Ned Harvey <[email protected]> writes:

> You seem to be in favor of AMD processors over Intel.  While I'll agree the
> purchase cost is lower, I never trust the rated power spec of any systems,
> and I always measure the actual fully-loaded power consumption of any
> servers I buy.  

not always.  Intel usually wins in situations where per-core performance
matters.

> My lowest power server is a Dell R610 Intel, 4 cores, 8 threads, 16G ram,
> 180W/190VA.
> My highest power server is a Dell 2970 AMD, 4 cores, 4 threads, 8G ram,
> 320w/325VA.

> Maybe I'm just buying the wrong AMD chips or something, but every time I
> test it, I would estimate the AMD processors are 2-4x higher power
> consumption than Intel, for equivalent processing power.

how are you getting 4 cores in a 2970?  are you using dual-core opterons?
if you are comparing two dual-core opterons with one quad-core xeon,
sure the opterons are going to use more power.   

of course, the r610 is also a dual-processor box, so maybe you are
just using dual-socket motherboards with single procesors in both
cases?  either way, that's a /whole lot/ more power than I'd expect
from a single CPU, unless you are using SE chips or something?  

Or are these both 2p dual core systems? 

(this is why I think it's confusing to talk about systems by their
dell or HP model;   usually that gives you a lot less information that
mentioning the CPUs, ram and disk involved.  Sure, the dell and HP
sales guys like to think there is a big difference between dell 
xeons and HP xeons, but there's not.) 

The other thing to consider is that each disk is going to eat 
around 10 watts, and the 2970 can hold more.  

measuring at the plug, the boxes I'm currently using for small VPSs

http://www.supermicro.com/Aplus/system/1U/1012/AS-1012G-MTF.cfm

in production, with an 8 core 2Ghz amd eats around 120 watts,
according to my APC pdu.   This is the 115w rated chips, not
the HE edition.  

In my experience, a reasonably chosen amd system  will beat a
equivalant intel system per-core on power usage. 

This was not true after Intel moved to QPI (the nehalam, 55xx series
xeons)  before amd came out with the G34 socket chips.   The Nehalam 
platform was pretty solid... it look a lot of the ideas from the AMD 
arcatecture (QPI looks a whole lot like hyper transport)  and implemented 
them better.  it was certainly better than the socket F opterons.  But now 
that the G34 opterons are out, AMD has regained their lead.

It's interesting because before nehalam, qpi, and the move to 
ddr3 and away from FBDIMMs, AMD socket F was lower power than the 
intel Xeons/FBDIMM setups.  But when Nehalam came out, damn, it looked
like the end for AMD.  

Back in the pre-nehalam days, when intel used a shared FSB and FBDIMMS, 
which often use as much as 10 watts each,   you could save clients
more than half their power bill by moving them from low power xeons
with FBDIMMS to low power xeons with reg. ecc ddr2.  (you could use
the same xeons, this was before intel started putting the memory
controller on the cpu, so you did need to replace the motherboard.)

Once I was hired to do a blade eval for a client.  The blades used low
power xeons, but they also used FBDIMMS.  I got them to order some
pizza boxes from Dell (the DCS division?)  that used the same low 
power xeons and registered ecc ddr2 rather than FBDIMMS.  the pizza 
boxes blew the blades out of the water. 


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