Mac Pro 3,1 with 58GB server RAM running hot

[pullman]

I have installed 58GB of server RAM in my 3,1. All sticks passed Rember's tests.

When I today encode ripped DVDs with Handbrake the fans spin very fast. Hardware Monitor says that the Exhaust and CPU/Memory fans are at 1500+ rpm when Handbrake runs.

When I only had 20GB 800MHz RAM installed this would never ever happen even if I ran MakeMKV and did other things, like edit in Photoshop, in parallel with Handbrake.

Hardware Monitor says that Riser B's four 667 MHz modules are at 73-79C.

On Riser A I have two 667 MHz modules which also are at 77-78C but the two 4GB 800 MHz modules are at a more reasonable 54-55C.

1. Has anyone else noticed increased fan speeds with server RAM installed?
2. Do they 667 MHz sticks look like they've got insufficient heat sinks?
3. Is it a question of not enough thermal paste? If so where - here in Europe - might I find that and how do I apply that?

I'm considering to return them and hope for a better set from Mr Memory but would appreciate your thoughts before I do because I've never run the system with this amount of RAM before.

EDIT: I re-installed the 800 MHz RAM sticks (only) and experience no fan increase at all when I rip a DVD with MakeMKV and encode another in parallel with Handbrake.

Thanks a lot in advance.
Philip

 

[Pressure]

FB-DIMMS are hot. My fully populated Mac Pro ranges from 57 to 71C average over all 8 slots. They all have the Apple heatsinks on them though.

 

[Ludacrisvp]

You need better heatsinks. Those won't work well under pressure with the way the 08 moves air. They may work OK in the xserve due to the different thermal profile of the 1U server.
I'd get real FBDIMMS made for the Mac pro that are 800mhz.

 

[pullman]

Thanks for the replies. From having read several posts here and an article at Barefeats I understood that is no problem in principle for the machine to use such RAM.

Perhaps I'll try to use the heatsinks from some broken 800 MHz sticks I have.

FB-DIMMS are hot. My fully populated Mac Pro ranges from 57 to 71C average over all 8 slots. They all have the Apple heatsinks on them though.

You need better heatsinks. Those won't work well under pressure with the way the 08 moves air. They may work OK in the xserve due to the different thermal profile of the 1U server.
I'd get real FBDIMMS made for the Mac pro that are 800mhz.

 

[Spacedust]

Replace them right away as long they are still working! I've used to have such modules as they were very cheap, but 4 out 8 failed in the first year, because of overheating.

You need modules like this:

 

[pullman]

Thanks for the reply. Did you try to replace the heatsink on the server RAM sticks with the big black ones from 800MHz sticks?

Replace them right away as long they are still working! I've used to have such modules as they were very cheap, but 4 out 8 failed in the first year, because of overheating.

You need modules like this:

 

[pl1984]

I recommend you return them and pick up memory with the appropriate heatsinks (as shown in Spacedusts post). You can use the Mac Pro 1,1's 667MHz modules if you do not want to pay for the Mac Pro 3,1's 800 modules.

 

[MoerBoer]

Had the same issues on my Mac Pro 1.1. Memory worked, but the fans were always running more than needed and the temps were high.

Eventually ordered the correct ones as per photo above from eBay and it's been quiet and cool since then.

 

[w1z]

Thanks for the reply. Did you try to replace the heatsink on the server RAM sticks with the big black ones from 800MHz sticks?

I did for the 8GB x 8 667Mhz server-grade Crucial sticks I bought for my 3,1 although I am only using 56GB with High Sierra - see link in my sig for reason. I procured the cheapest Apple FB-DIMMS sticks from ebay, $10 I think, as well as thermal tape and replaced all of them with ease. You can also use thermal compound but the process is messy as I tried it and ended up using tape instead.

Max temps with default fan speeds around 49C / Ambient temp 25C / FB-DIMM outgoing air temp 41C. At peak load, temps would reach 56/57C.

 

[pullman]

Thanks for chiming in. I read your past posts about this and found them very helpful.

Today I put the Apple-type heatsinks on the server sticks but the fans rev maximum as soon as I boot so something's definitely afoot with those sticks. I'll return them and then think about whether I'll go for 4x4GB or try another set of server sticks.

What kind of thermal tape did you use? I'm looking at Ebay but only see products from Hong Kong and Australia, nothing in Europe.

br
Philip

I did for the 8GB x 8 667Mhz server-grade Crucial sticks I bought for my 3,1 although I am only using 56GB with High Sierra - see link in my sig for reason. I procured the cheapest Apple FB-DIMMS sticks from ebay, $10 I think, as well as thermal tape and replaced all of them with ease. You can also use thermal compound but the process is messy as I tried it and ended up using tape instead.

Max temps with default fan speeds around 49C / Ambient temp 25C / FB-DIMM outgoing air temp 41C. At peak load, temps would reach 56/57C.

 

[w1z]

Thanks for chiming in. I read your past posts about this and found them very helpful.

What kind of thermal tape did you use? I'm looking at Ebay but only see products from Hong Kong and Australia, nothing in Europe.

br
Philip

I think the brand was Gelid and the thickness was 1mm. I applied the tape on both sides of each memory stick.

 

[MoerBoer]

Thanks for chiming in. I read your past posts about this and found them very helpful.

Today I put the Apple-type heatsinks on the server sticks but the fans rev maximum as soon as I boot so something's definitely afoot with those sticks. I'll return them and then think about whether I'll go for 4x4GB or try another set of server sticks.

What kind of thermal tape did you use? I'm looking at Ebay but only see products from Hong Kong and Australia, nothing in Europe.

br
Philip

I used these guys : https://www.ebay.com/itm/16GB-KIT-4...917666?hash=item33af17ffa2:g:akAAAOSw~otWgunl

Memory is brand new. Given this is the 667Mhz, but I'm sure they sell the 800Mhz too.

 

[AlexMaximus]

Thanks for chiming in. I read your past posts about this and found them very helpful.

Today I put the Apple-type heatsinks on the server sticks but the fans rev maximum as soon as I boot so something's definitely afoot with those sticks. I'll return them and then think about whether I'll go for 4x4GB or try another set of server sticks.

What kind of thermal tape did you use? I'm looking at Ebay but only see products from Hong Kong and Australia, nothing in Europe.

br
Philip

I think you should avoid mixing that two different gen. ram sticks. If you stay with the 800Mhz, you will be fine.
The older Gen 667mhz sticks are much slower. The 800mhz are faster and a bit hotter, so you might want to consider an additional cooler.

http://www.maxupgrades.com/istore/index.cfm?fuseaction=category.display&category_ID=408

(last option below)

 

[w1z]

I think you should avoid mixing that two different gen. ram sticks. If you stay with the 800Mhz, you will be fine.
The older Gen 667mhz sticks are much slower. The 800mhz are faster and a bit hotter

The 667MHz sticks run a tad slower, cooler and are cheaper than the 800MHz.. http://barefeats.com/harper5.html