Do I need heat sinks on my Mac Pro 1,1's memory?

[PowerMac G4 MDD]

I am wanting to purchase RAM for my Mac Pro 1,1. I am looking at some online right now...

"Hynix 16GB (4X4GB) DDR2 PC2-5300 667MHz 240pin ECC REG SERVER HYMP351P72AMP4-Y5"

These modules don't have heat sinks on them, though. Would these sticks get too hot in my Mac Pro? I sort of wanted 4x 4GB sticks, rather than 8x 2GB sticks… but, sadly, the only listings with RAM that has heat sinks are the 8x 2GB-RAM listings.

Also, does it have to be a special, Apple-branded heat sink, or is it okay if it's the common type of heat sink.

-Thanks

(I want to combine this RAM with my existing 4x 1GB sticks of RAM. I believe these ones have heat sinks.

 

[bladerunner2000]

Go for the 2x8gb, you'll have some empty slots that way for even more ram upgrades in the future. No point in using up more of them for less ram.

 

[PowerMac G4 MDD]

Go for the 2x8gb, you'll have some empty slots that way for even more ram upgrades in the future. No point in using up more of them for less ram.

I said eight 2GB RAM sticks. Anyway, the main question was whether they need heat sinks or not.

 

[mikeboss]

these modules are unbuffered, they won't work. you need FB (fully buffered) DIMMs.

 

[PowerMac G4 MDD]

these modules are unbuffered, they won't work. you need FB (fully buffered) DIMMs.

Okay, I found various listings for RAM advertised as being for the Mac Pro. However, I'd like to know if it's imperative for the RAM sticks to have the big, Apple-branded heat sinks, or if it's just fine for them to have those common, smaller heat sinks. Here is an example of Mac Pro RAM w/o the Apple heat sinks:

http://www.ebay.com/itm/16GB-8x-2GB...716?pt=LH_DefaultDomain_0&hash=item20dc178a44

Also, is 5300F the correct RAM type? Or does it HAVE to say FB? I saw some cheaper sticks (still with the non-Apple heat stinks) that were labeled as such. Here's one:

http://www.ebay.com/itm/8GB-4x-2GB-...523?pt=LH_DefaultDomain_0&hash=item566ad5d2f3

This one actually happens to say 'FB.'

Or perhaps this is good?: http://www.ebay.com/itm/16GB-8x-2GB...675?pt=LH_DefaultDomain_0&hash=item35deeb7d4b

 

[mikeboss]

lots of people are using DIMMs with the smaller heat sinks. personally, I'd want modules with large heatsinks. the AMB (advanced memory buffer) can get really hot. the modules have a temperature sensor and the Mac Pro adjusts the speed of the fans accordingly.

 

[PowerMac G4 MDD]

lots of people are using DIMMs with the smaller heat sinks. personally, I'd want modules with large heatsinks. the AMB (advanced memory buffer) can get really hot. the modules have a temperature sensor and the Mac Pro adjusts the speed of the fans accordingly.

My RAM sticks (4x 1GB) are currently running at an average of 126F each (ambient air 70F). How hot would these other ones run? If the heat sinks are removable, I COULD just swap them with the new sticks I get, unless I feel like having 20GB of RAM.

It looks like the Apple heat sinks are easily removable, but I don't know about the smaller heat sinks on these chips that are for sale.

 

[ActionableMango]

It looks like the Apple heat sinks are easily removable, but I don't know about the smaller heat sinks on these chips that are for sale.

I would definitely want the larger heat sinks with the actual fins, as that's the original design. What you are calling a small heat sink is really just a heat spreader. The heat spreaders are removable; just pop the spring clips off. Usually the only thing stopping that is a "warranty void if removed" sticker, but you're not getting a warranty with used Ebay ram anyway.

Don't forget to thoroughly test the RAM with something like a memtest boot CD. There is a lot of bad ram out there.

 

[Bubalight]

Some ram will work, other ram will overheat and error. These macs do a terrible job of revving up the fans to keep the memory cool. If you are willing to install smcfancontrol and set the fans to idle at 900-1100rpm (instead of 500) then you will probably not have any issues. If you are determined the apple heat sinks can be removed and installed on ram with heat spreaders, but you will need new paste and the pads sometimes tear or are just difficult to pull off intact. Even with the apple heat sinks retrofitted, I have tended to have one or two sticks out of 8 fail under stress testing, and need to be replaced.

 

[ZombiePhysicist]

I used to have 3 8GB sticks @1333mhz with heat sinks and since replaced it with 8 16GB sticks @1333mhz with no heat sinks. The newer 16GB sticks without heat sinks run way cooler than the older 8GB sticks with heat sinks. So it just depends on the memory.

 

[mikeboss]

I used to have 3 8GB sticks @1333mhz with heat sinks and since replaced it with 8 16GB sticks @1333mhz with no heat sinks. The newer 16GB sticks without heat sinks run way cooler than the older 8GB sticks with heat sinks. So it just depends on the memory.

yeah, we're talking about completely different modules here. your 1333 MHz DIMMs are R-DIMMs and/or U-DIMMs (DDR3) while the ones the OP is talking about are DDR2 FB-DIMMs.

 

[PowerMac G4 MDD]

Some ram will work, other ram will overheat and error. These macs do a terrible job of revving up the fans to keep the memory cool. If you are willing to install smcfancontrol and set the fans to idle at 900-1100rpm (instead of 500) then you will probably not have any issues. If you are determined the apple heat sinks can be removed and installed on ram with heat spreaders, but you will need new paste and the pads sometimes tear or are just difficult to pull off intact. Even with the apple heat sinks retrofitted, I have tended to have one or two sticks out of 8 fail under stress testing, and need to be replaced.

Hmm... well, maybe I'll just have to get RAM that is being sold with the Apple heat sinks already attached, assuming that retrofitting could be an issue. It's difficult to decide, considering everyone has had different experiences with this 3rd party RAM and heat spreaders vs. heat sinks. It's too bad that the genuine ones are so expensive. I wouldn't want to adjust my fans speeds either; I like a quiet machine. I guess I don't need to go big. I'll just get an extra 4GB and have 8GB total. The 4GB isn't doing it for me, as Mountain Lion takes up, like, half of it or more with only one application open. Using Illustrator, iTunes, Mail, and Safari, I only have 20MB-384MB free.

 

[nigelbb]

The 667MHz FB-DIMMs are so cheap that why not just buy some & try them? The linked eBay listing has 16GB (4x4GB) for just $19.95. They don't have any heat sink or spreader though. I have upgraded two Mac Pro 3,1s to 32GB with 8x4GB 667MHz FB-DIMMs & they perform great. The RAM I bought does have heat spreaders.

Actually I just checked eBay & even 667MHx FB-DIMMs with Apple heatsinks are very cheap now. These are just $30 for 8GB (2X4GB). http://www.ebay.co.uk/itm/8GB-2X4GB...062?pt=LH_DefaultDomain_0&hash=item25a659d8fe

You may as well buy these with heat sinks rather than without & take the risk of overheating.

 

[PowerMac G4 MDD]

The 667MHz FB-DIMMs are so cheap that why not just buy some & try them? The linked eBay listing has 16GB (4x4GB) for just $19.95. They don't have any heat sink or spreader though. I have upgraded two Mac Pro 3,1s to 32GB with 8x4GB 667MHz FB-DIMMs & they perform great. The RAM I bought does have heat spreaders.

Actually I just checked eBay & even 667MHx FB-DIMMs with Apple heatsinks are very cheap now. These are just $30 for 8GB (2X4GB). http://www.ebay.co.uk/itm/8GB-2X4GB...062?pt=LH_DefaultDomain_0&hash=item25a659d8fe

You may as well buy these with heat sinks rather than without & take the risk of overheating.

Yeah, I actually saw that listing on eBay and was considering it. I hate putting money into an old computer, but I'm using this machine for productive purposes and don't like to see my free memory at 20-384MB.

 

[ZombiePhysicist]

yeah, we're talking about completely different modules here. your 1333 MHz DIMMs are R-DIMMs and/or U-DIMMs (DDR3) while the ones the OP is talking about are DDR2 FB-DIMMs.

True, but I think that misses the point. My earlier RDIMMs ran hotter than my later RDIMMs. So later produced versions of the same memory may run cooler even without a heat sink. So it just depends on the memory/fab.

 

[PowerMac G4 MDD]

True, but I think that misses the point. My earlier RDIMMs ran hotter than my later RDIMMs. So later produced versions of the same memory may run cooler even without a heat sink. So it just depends on the memory/fab.

I may go with some ones I found on eBay that have the legit heatsinks. I don't want to risk anything with cheap memory--new or not.

 

[ActionableMango]

Yeah, I actually saw that listing on eBay and was considering it. I hate putting money into an old computer, but I'm using this machine for productive purposes and don't like to see my free memory at 20-384MB.

Just a possibility, but if you are seeing a large amount of memory used for cache, then that's basically available RAM too. I think somewhere around the time of Mavericks, OS X starting using main memory as disk cache instead of wasting it. The side result is that it looks like there is very little free RAM when in fact all of the memory used for cache is available any time as well.

This is not necessarily your case of course, I just thought I'd mention it on the chance you didn't know. It's possible you could check and not need to increase your RAM at all.

 

[PowerMac G4 MDD]

Just a possibility, but if you are seeing a large amount of memory used for cache, then that's basically available RAM too. I think somewhere around the time of Mavericks, OS X starting using main memory as disk cache instead of wasting it. The side result is that it looks like there is very little free RAM when in fact all of the memory used for cache is available any time as well.

This is not necessarily your case of course, I just thought I'd mention it on the chance you didn't know. It's possible you could check and not need to increase your RAM at all.

Oh yeah, I remember them doing that with Mavericks. I, however, am running Mountain Lion. I can maybe post a picture of my Activity Monitors stats when I get the chance. I actually first discovered my RAM usage when I had Adobe Illustrator (and a few other applications) open, and then tried opening my web browser, only to see an error from the browser that I didn't have enough free memory to run it. Of course, that error didn't come back after I restarted my browser, but I did notice in Activity Monitor that about 20MB of RAM was free. With nothing running, it looks as though Mountain Lion is hogging over 1GB of it... almost like how Windows just automatically steals a portion of your RAM w/o anything running.

 

[ActionableMango]

Yes, it sounds like you definitely need more RAM. I probably should have just looked at your sig and I would have seen the "4GB".

Granted, my 2010 came with even less than that, but that's Apple being stingy!

 

[kwikdeth]

you want the sticks with heatsinks on them for the 1,1 and 2,1 mac pros. they are FB-DIMMs and have extra components on them which run hotter than the main memory (the buffer i believe). this is the reason they have heatsinks. its extremely rare to find a FB-DIMM that doesnt have a heatsink on it, just do a image search for "FB-DIMM"

i dont think you need the massive heatsinks that the original Apple memory had on them, but you definitely want some kind of heatsink on your FB-DIMMs


take a look at this link - even FB-DIMMs without heatsinks still have a heatsink on that center component - that's the source of the heat and the reason for the heatsink
http://www.ixbt.com/short/2k4-12/2004-12-20_FB-DIMM.jpg

 

[PowerMac G4 MDD]

you want the sticks with heatsinks on them for the 1,1 and 2,1 mac pros. they are FB-DIMMs and have extra components on them which run hotter than the main memory (the buffer i believe). this is the reason they have heatsinks. its extremely rare to find a FB-DIMM that doesnt have a heatsink on it, just do a image search for "FB-DIMM"

i dont think you need the massive heatsinks that the original Apple memory had on them, but you definitely want some kind of heatsink on your FB-DIMMs


take a look at this link - even FB-DIMMs without heatsinks still have a heatsink on that center component - that's the source of the heat and the reason for the heatsink
http://www.ixbt.com/short/2k4-12/2004-12-20_FB-DIMM.jpg

Yeah - some have said that even the smaller heat sinks aren't enough, but everyone seems to have had different experiences. I may bite the bullet and go for a more expensive sale of 8GB of RAM that has the large Apple heat sinks. I feel bad spending $30 on RAM, though, especially when I can get 16GB of the small heat sink RAM for about that price. However, it's best to be safe. I don't want to fry RAM or cause the rear exhaust fan to go up.