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View Full Version : How important is the "Apple certified temperature sensor" for memory?




mattmower
Aug 31, 2010, 04:20 AM
The Apple memory that comes with the Mac Pro has, I believe, a temperature sensor. So does the memory that comes from OWC in the US.

I'm in the UK and have always bought memory from Crucial. However although Crucials 4GB modules are unbuffered (unlike their 8's) they have confirmed that they have no temperature sensor.

I'm not sure whether this is a complete non-issue, or has the potential to cause me problems.

I'm buying my 6-core as an audio workstation. The last thing I want is extra fan noise because the Mac can't sense the temperature of the memory modules I have installed.

Is this possible? Likely?

It's a little bit cheaper buying the memory from OWC in the US (I'm always inquiring of Kingston about their memory) but comes with some extra risk and costs if I get unlucky and have to ship back for replacement.

Can anyone settle this for me? Is the temperature sensor important?

Thanks.

Matt



Vylen
Aug 31, 2010, 04:29 AM
From previous posts regarding the (lack of a) temperature sensor... OS X will regard it as a hardware failure and tell you, and ramp up the fans to maximum since it doesn't know if they are hot or cold or whatever.

mattmower
Aug 31, 2010, 05:09 AM
That's certainly my fear. But I'm not sure I can recall read anything from someone who actually has the memory without a temp sensor and is having this problem, i.e. I've seen the speculation but I'm not sure i've seen any evidence.

Matt

Vylen
Aug 31, 2010, 05:17 AM
For lack of anything official with the recent Mac Pro's that use DDR3 RAM, it's presumed to be a carry-over from the FB-DIMM days... specifically:

The Mac Pro will run the fans at full speed when detecting FB-DIMM's without a functional temperature sensor, which will maximize cooling on the FB-DIMM's. While the full speed of the fans maximizes the preservation of thermal integrity, FB-DIMMs with inadequate heat sinking may still overheat depending on ambient temperature and system load. In this case, the Mac Pro may shut down the system to protect the FB-DIMM from possible thermal damage.

http://developer.apple.com/mac/library/technotes/tn2006/tn2156.html

Otherwise, why else have RAM modules with a temperature sensor in them, if the system isn't going to react to them (or a lack thereof) properly?

mattmower
Aug 31, 2010, 05:30 AM
You make a good case. I'm just puzzled why, in that case, anyone would buy memory without temp. sensors and why, therefore, a company like Crucial would sell them.

Since quietness is important factor to me (one of the reasons I went for the 5770 instead of the 5870) I'll play it safe and make sure whatever memory I buy has temp sensors.

I guess that probably means I will be ordering from OWC in the US.

Matt.

mattmower
Aug 31, 2010, 07:06 AM
I've just had it confirmed that Kingston supply unbuffered 4GB modules with an Apple approved temperature sensor.

Their web only price (http://www.cancomuk.com/Brand/Kingston/Product/68779?___Kingston-4GB-1333MHz-DDR3-ECC-Memory-Module-(-Mac-Pro-2010-edition-)-KTA-MP1333-4G) of £129 inc. VAT is also very good, beating Crucial by £20.

The same memory from OWC is about £250+shipping when you factor in duty so I think I'll probably order the Kingston memory.

Matt

NickCG
Aug 31, 2010, 08:26 AM
I've just had it confirmed that Kingston supply unbuffered 4GB modules with an Apple approved temperature sensor.

Their web only price (http://www.cancomuk.com/Brand/Kingston/Product/68779?___Kingston-4GB-1333MHz-DDR3-ECC-Memory-Module-(-Mac-Pro-2010-edition-)-KTA-MP1333-4G) of £129 inc. VAT is also very good, beating Crucial by £20.

The same memory from OWC is about £250+shipping when you factor in duty so I think I'll probably order the Kingston memory.

Matt

Pity they don't seem to have the 1066 ram for the 3.2 quad though.

mattmower
Aug 31, 2010, 08:30 AM
Pity they don't seem to have the 1066 ram for the 3.2 quad though.

Is there a big price difference in the market between 1066 & 1333 memory? If not then my understanding is that the 1333 memory will just be addressed at the slower speed required.

Matt

Umbongo
Aug 31, 2010, 09:14 AM
Pity they don't seem to have the 1066 ram for the 3.2 quad though.

As mattmower said, it will down clock to 1066MHz. Only 1333MHz memory is officially supported on the 2010 Mac Pros and all models come with it.

NickCG
Aug 31, 2010, 10:19 AM
Ah, sorry. I should have stated that I understood that. Just trying to count the pennies. ;)

CaptainChunk
Sep 1, 2010, 02:37 AM
The presence of a temperature sensor has nothing to do with whether the memory module is buffered (registered) or unbuffered (unregistered). They're two completely different things.

Registered memory simply implies that there is a register on the memory module to reduce the electrical load between the module and the memory controller, improving stability, especially in applications where high-capacity modules are used (like 8GB modules, for example).

daver11
Sep 1, 2010, 02:42 AM
Always buy RAM directly from Apple. Their RAM is hundreds of dollars better than the competitors! <insert sarcasm>

2contagious
Sep 1, 2010, 06:27 AM
I've just had it confirmed that Kingston supply unbuffered 4GB modules with an Apple approved temperature sensor.

Their web only price (http://www.cancomuk.com/Brand/Kingston/Product/68779?___Kingston-4GB-1333MHz-DDR3-ECC-Memory-Module-(-Mac-Pro-2010-edition-)-KTA-MP1333-4G) of £129 inc. VAT is also very good, beating Crucial by £20.

The same memory from OWC is about £250+shipping when you factor in duty so I think I'll probably order the Kingston memory.

Matt

Does anyone know if adding this 4GB stick to the existing 3x 1GB that come with the 2010 Mac Pro hexacore will work? So.. 1GB-1GB-1GB-4GB=7GB RAM? Would be a quick cheap fix for me.

NickCG
Sep 1, 2010, 07:12 PM
I asked Crucial if the 4GB sticks contained and Thermal Sensor, they responded with:

"Hello Nick,

Thank you for contacting us. Yes, this memory has a thermal sensor on it.

If you have further questions, please visit... *blah, blah*.. etc, etc".


So, what are they on about?;p

sboerup
Sep 1, 2010, 07:52 PM
Hrmmm, this thread is interesting. Transintl.com seems to have the best prices and it's good RAM. Is Crucial or anyone THAT much cheaper? Or is this searching mainly for the non-USA folk?

wibongo
Sep 2, 2010, 12:34 AM
As mattmower said, it will down clock to 1066MHz. Only 1333MHz memory is officially supported on the 2010 Mac Pros and all models come with it.

The 6 and twelve core machines use 1333 memory, the 4 and 8 cores still use 1066, FYI. But you can still stick 1333 memory in any of them and it will work and slow down if needed.

Prince134
Sep 2, 2010, 01:07 AM
From previous posts regarding the (lack of a) temperature sensor... OS X will regard it as a hardware failure and tell you, and ramp up the fans to maximum since it doesn't know if they are hot or cold or whatever.

I have onfirmed with Super Talent Technical support manager that all Server DDR3 (not only from SuperTalent) you can buy now should include temperature sensor in the eeprom. This is because when ECC + REG specs together bring to fully compliance to JEDEC as mandatory.

Optionally, ECC/unbuffered DRAM can be with or without temperature sensor, and that's why maker will mark their item as support TS, in which case can be used for Mac Pro.

glassbathroom
Sep 2, 2010, 01:21 AM
I asked Crucial if the 4GB sticks contained and Thermal Sensor, they responded with:

"Hello Nick,

Thank you for contacting us. Yes, this memory has a thermal sensor on it.

If you have further questions, please visit... *blah, blah*.. etc, etc".


So, what are they on about?;p

I hope this is correct. I can't believe Crucial would sell RAM that doesn't match the Apple spec. I have my Crucial RAM, is there any easy way to check. The packaging is not very informative.

mattmower
Sep 2, 2010, 01:53 AM
I hope this is correct. I can't believe Crucial would sell RAM that doesn't match the Apple spec. I have my Crucial RAM, is there any easy way to check. The packaging is not very informative.

After two different people at Crucial had told me there was no temperature sensor I told them I wouldn't order the memory from them since there were other vendors who did.

Then I got back a further message:

We have looked into this and all our DDR3 modules have temperature sensors built into the module.

We had to confirm this direct from the manufacturer today and they have advised that the 4GB modules should have the chips installed but they do not have heat sinks.

If you do order the memory and you do notice a difference in the sound of your fan you are free to return the item within 45 days as part of our return policy.

I've never had a problem with Crucial's memory in the past so I'm inclined to look past the "should" and believe I just got bad information from the first two people.

Matt.

glassbathroom
Sep 2, 2010, 03:46 AM
After two different people at Crucial had told me there was no temperature sensor I told them I wouldn't order the memory from them since there were other vendors who did.

Then I got back a further message:



I've never had a problem with Crucial's memory in the past so I'm inclined to look past the "should" and believe I just got bad information from the first two people.

Matt.

Good stuff. Well done.