Cramming Heatsinked RAM into an Imac g5

[ratdude747]

Yesterday my fresh (to me) RAM for my gen 1 Imac G5 came in... 2x 1GB of PC3200... however, it's heatsinked super talent gaming ram (got it for cheap, what the hell). I figured the heatsinks/spreaders would help given the G5's piss poor cooling... but..

It was a VERY tight fit. It barely fit... the heatspreaders are touching eachother and the inner one is also touching the CPU heatsink.

The system sees and seems to like the RAM... but does the tight fit nullify the cooling effects of the heat spreader? Would I be better off finding a mate for my 1gb PC3200 kingston module that came out instead?

I'll have to get a picture...

[larrymoencurly]

Re: Cramming Heatsinked RAM into an Imac g5

I thought the low power levels of those RAM chips and their high temperature ratings (85C) made heatsinks completely unnecessary, and heatsinks are put on retail memory modules only for marketing purposes and to cover up the fact that the chips are no-name or overclocked. XbitLabs.com and APHnetworks.com have taken the heatsinks off some modules to reveal that fact, but in the process they sometimes ripped chips or copper traces from the circuit boards.

Many years ago, I found that about 8 out of 13 Kingston 512MB PC3200 modules had defects, and about 1-2 years ago I got a defect rate of about 30% with Corsair 1GB PC3200 modules.

[ratdude747]

Re: Cramming Heatsinked RAM into an Imac g5

My understanding was that the use of heatsinks was to allow easier overclocking by the end user... the RAM seems to work OK and all. I also got some 512mb OCZ PC3200 sticks as well in the shipment, also heatsinked.

It should be safe to use, right?

[Pentium4]

Re: Cramming Heatsinked RAM into an Imac g5

I think they're good up to 105C, they seem to idle around 85C...(semi-sarcastic)

[larrymoencurly]

Re: Cramming Heatsinked RAM into an Imac g5

Heatsinks have almost nothing to do with overclockability and a lot to do with marketing because it's cheaper to slap on fancy heatsinks and use untested or overclocked chips rather than use branded, guaranteed chips of the advertised speed rating.

I haven't done much checking, but the highest operating temperature spec I've seen is 95C case temp, if the refresh rate is doubled. Otherwise 85C is the max

Back in 2006, Corsair tried different heatsinks on a Corsair or OCZ DDR module run at 3.4V and 2-2-2-5 timings in a 68F (probably a misprint for 68C) test chamber, and the best heatsink allowed only a 1.6% faster speed than no heatsink:

http://www.legitreviews.com/article/299/

Maximum speeds:

250 MHz........no heatsink
253 MHz........OCZ aluminum mesh heatsink
253 MHz........Corsair stamped aluminum heatsink
254 MHz........Corsair cast aluminum heatsink

[ratdude747]

Re: Cramming Heatsinked RAM into an Imac g5

So should I not use the RAM then, if heatsink'd non-RAMBUS = junk?

[shovenose]

Re: Cramming Heatsinked RAM into an Imac g5

So should I not use the RAM then, if heatsink'd non-RAMBUS = junk?

I don't think that's what's being implied. That RAM is good quality; just because it has heat spreaders doesn't mean it's crap. The heatsinks are more commonly referred to as heat spreaders for a reason - they spread the heat from the little RAM chips to a large surface area. They don't really cool the chips that much more. However, in low airflow situations I doubt they make a huge difference, but they also won't make it worse.

[ratdude747]

Re: Cramming Heatsinked RAM into an Imac g5

FYI. some datasheets/info (if they matter):

Super talent: https://cdn.badcaps-static.com/pdfs/...c94565e4c5.pdf

OCZ: http://www.ocztechnology.com/ocz-el-...tinum-eol.html

So my ulitmate question is: if the heat spreaders are right against eachother and a CPU heatsink like so:



is the fact i'm using ram with heatspreaders helping or hurting me?

[shovenose]

Re: Cramming Heatsinked RAM into an Imac g5

FYI. some datasheets/info (if they matter):

Super talent: https://cdn.badcaps-static.com/pdfs/...c94565e4c5.pdf

OCZ: http://www.ocztechnology.com/ocz-el-...tinum-eol.html

So my ulitmate question is: if the heat spreaders are right against eachother and a CPU heatsink like so:



is the fact i'm using ram with heatspreaders helping or hurting me?

Helping you.

[Elysarian]

Re: Cramming Heatsinked RAM into an Imac g5

Personally the only concern I'd have is whether they're putting pressure/stress on the sockets, I don't see an issue if they're just touching though.

[larrymoencurly]

Re: Cramming Heatsinked RAM into an Imac g5

So should I not use the RAM then, if heatsink'd non-RAMBUS = junk?

I say you have to test it like crazy with both MemTest86/86+ and Gold Memory, running each for at least 2 hours, preferrably in at least 2 different types of motherboards. About 10% of the modules I've checked that had heatsinks or unbranded chips were defective, but I've seen only one bad module with prime quality chips and no heatsinks. Actually that module may have been OK, but I refused to run it because it made a crunchy sound when I plugged it in, and it turned out to have solder on 2 of its gold contacts, and a sliver of solder probably fell out of the DIMM socket.

Those 1GB Corsair DDR modules I bought were rated 3-3-3-8 on their label but 3-4-4-8 according to their SPDs. I couldn't find any DDR chips as slow as 3-4-4-8 at Micron or Samsung, leading me to suspect they were made from failed 3-3-3-8 chips.

Those heatsinks on your modules are making no difference at all. I've tried heating up DDR2 and DDR3 modules during testing by covering them with anti-static foam sheet, but they stayed below 70C. The sockets seem to tolerate the modules having some side pressure on them because I had a DIMM socket that was sensitive to wiggling and would make the computer freeze each time the DIMM was touched, but it turned out a piece of lint was stuck to one of the socket pins, and after removing it I could wiggle the module quite a bit without causing MemTest86 to report errors.

[ratdude747]

Re: Cramming Heatsinked RAM into an Imac g5

^ Yeah, I wish I had the time to do that... I could technically though. PO of the modules reported no issues, and I'm somewhat certain he memtested them in at least one motherboard.

[shovenose]

Re: Cramming Heatsinked RAM into an Imac g5

^ Yeah, I wish I had the time to do that... I could technically though. PO of the modules reported no issues, and I'm somewhat certain he memtested them in at least one motherboard.

Confirmed., no errors in a weird DFI LGA775 Pentium4 board. It's the OCZ that's iffy.

[kaboom]

Re: Cramming Heatsinked RAM into an Imac g5

It's the OCZ that's iffy.

No surprise there!


As for the heatspreaders. They're an ugly reminder of the RAMBUS days. RDRAM could concentrate all heat output onto a single chip, and also had a habit of running hot.

Now, stupid "GAM3R" heatsinked RAM SPDs bullshit settings to push things too far. 2.1V vs 1.8V, and timings that are too tight, sometimes (usually?) using reject chips.

No wonder that current heatsinked RAM has become suspect...

It's like ASUS and newegg advertising that a given board will run at 2166(OC). More bullshit! All other boards with the same chipset don't go that high, and the chipset datasheets don't specify it either!

ASUS/AS(C)ROCK and antec, whatta perfect match:
2166(OC)
1666(OC)
1333
1066
800

Those 1GB Corsair DDR modules I bought were rated 3-3-3-8 on their label but 3-4-4-8 according to their SPDs. I couldn't find any DDR chips as slow as 3-4-4-8 at Micron or Samsung, leading me to suspect they were made from failed 3-3-3-8 chips.

And probably run higher than spec voltage, too.
Even more bullshit!

That's the problem- these "Brand Name" companies, using, um, their brand recognition, to leverage potential buyers...
The same thing antec did a few years ago...

[shovenose]

Re: Cramming Heatsinked RAM into an Imac g5

And that's why I like MSI motherboards... if only they made RAM

[RJARRRPCGP]

Re: Cramming Heatsinked RAM into an Imac g5

Those 1GB Corsair DDR modules I bought were rated 3-3-3-8 on their label but 3-4-4-8 according to their SPDs.

Looks like it's relabelled PC2700. Likely intended to be factory-OC'ed PC2700.

[Gordon01]

Re: Cramming Heatsinked RAM into an Imac g5

is the fact i'm using ram with heatspreaders helping or hurting me?

Do nothing, I think)

[stj]

Re: Cramming Heatsinked RAM into an Imac g5

do NOT remove the heatsinks,

i did that to a couple of old dimms and found that they used DIY-ON-BOARD technology under the sink with no chip packages!

[Ed Herdman]

Re: Cramming Heatsinked RAM into an Imac g5

I'd write Super Talent asking them if it's okay to remove the heatsinks.

It's a totally different machine than a G5, but I've got a large tower in which I placed a huge Noctua heatsink over my CPU. Unfortunately the heatsink is so big that is partially overhangs two of the RAM slots, and I couldn't place two of my RAM modules in with the heatsinks on. I wrote the manufacturer for guidance and they said it was fine. I haven't been overclocking the RAM or running hot temps inside the case, though, so it might work out totally different inside a G5.

However, this was a special heatsink type, which slides onto the top of the module and is held in place by tiny Philips screws. Obviously, if the heatsinks are glued on to the sides of the RAM chips, and the heatsinks comes off in long pieces, I would be wary of doing this. You might be able to get away with cutting down the heatsinks along their tops though.