Re: Request for feedback on hardware for a new database server

On Fri, Mar 18, 2011 at 6:44 AM, Arjen van der Meijden
<acmmailing(at)tweakers(dot)net> wrote:
> On 18-3-2011 10:11, Scott Marlowe wrote:
>>
>> On Fri, Mar 18, 2011 at 1:16 AM, Arjen van der Meijden
>> <acmmailing(at)tweakers(dot)net>  wrote:
>>>
>>> On 18-3-2011 4:02 Scott Marlowe wrote:
>>> We have several 1U boxes (mostly Dell and Sun) running and had several in
>>> the past. And we've never had any heating problems with them. That
>>> includes
>>> machines with more power hungry processors than are currently available,
>>> all
>>> power slurping FB-dimm slots occupied and two raid cards installed.
>>
>> Note I am talking specifically about the ability to cool the RAID
>> card, not the CPUS etc.  Many 1U boxes have poor air flow across the
>> expansion slots for PCI / etc cards, while doing a great job cooling
>> the CPUs and memory.  If you don't use high performance RAID cards
>> (LSI 9xxx  Areca 16xx 18xx) then it's not an issue.  Open up your 1U
>> and look at the air flow for the expansion slots, it's often just not
>> very much.
>>
>
> I was referring to amongst others two machines that have both a Dell Perc
> 5/i for internal disks and a Perc 5/e for an external disk enclosure. Those
> also had processors that produce quite some heat (2x X5160 and 2x X5355)
> combined with all fb-dimm (8x 2GB) slots filled, which also produce a lot of
> heat. Those Dell Perc's are similar to the LSI's from the same period in
> time.
>
> So the produced heat form the other components was already pretty high.
> Still, I've seen no problems with heat for any component, including all four
> raid controllers. But I agree, there are some 1U servers that skimp on fans
> and thus air flow in the system. We've not had that problem with any of our
> systems. But both Sun and Dell seem to add quite a bit of fans in the middle
> of the system, where others may do it a bit less heavy duty and less
> over-dimensioned.

Most machines have different pathways for cooling airflow over their
RAID cards, and they don't share that air flow with the CPUs. Also,
the PERC RAID controllers do not produce a lot of heat. The CPUs on
the high performance LSI or Areca controllers are often dual core high
performance CPUs in their own right, and those cards have heat sinks
with fans on them to cool them. The cards themselves are what make so
much heat and don't get enough cooling in many 1U servers. It has
nothing to do with what else is in the server, again because the
airflow for the cards is usually separate.