[geeks] Mac memory falling in price

Shannon Hendrix shannon at widomaker.com
Wed Dec 12 20:26:05 CST 2007


On Dec 12, 2007, at 6:19 PM, Mark wrote:

> On 12 Dec 2007, at 20:16, Shannon Hendrix wrote:
>
>> Not really.
>>
>> You compared memory that is "low end" compared to Mac memory.
>
>
>
>> Try comparing the same FB-DIMM quality for a PC and you'll find  
>> prices
>> are about the same.
>
> I think Xeons are the only rigs that use FB-DIMMs (hence the use in
> Mac Pros). I think the same FBDIMM RAM is actually slightly cheaper if
> you buy it for generic Xeon boxen because you don't have to pay for
> the 2 huge blocks of aluminum that are clamped over the Mac Pro
> units :) Before you ask, early 3rd party RAM for the MAc Pro used
> normal heat plates but it overheated due to the slightly jankey
> airflow design that Apple's interpretation of 'BTX' inflicts on the
> world.

Not sure what you mean.  The Apple Mac Pro motherboard looks to me  
like an Intel BTX server board.

The airflow is actually better than most tower cases I've seen,  
although it could certainly be better still.

The primary problem is the smc controller doesn't run the fans fast  
enough or react quickly enough to temperature increases.

The only PC server systems I've seen that didn't need huge heatsinks  
on FB-DIMMs also had fans that sounded like jet engines.

I'd really like to see one because they seem to be hot no matter who  
makes the boards and chassis.

I've got a 2U Xeon server leaned against a cabinet right now, and it  
doesn't have RAM heatsinks at all.  However, it also sounds like a jet  
airliner when you fire it up.  I think all three of its 80mm fans run  
at 4000rpm.

Regarding the Mac Pro:

The Mac Pro runs large fans at barely 600rpm, which I think is  
completely ridiculous.

It also doesn't react to temperature change fast enough.

Running smcfancontrol is the only solution I've been able to find.

The actual case airflow is not bad.  It should have been sealed better  
and they need to move or otherwise handle the northbridge heatsink  
(it's too close to the RAM), but the primary problem is fan speed, not  
airflow.

Apple seems to have no interest in fixing this problem.

-- 
Shannon Hendrix
shannon at widomaker.com



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