Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

nightfly13

macrumors 6502a
Original poster
Jul 17, 2008
679
0
Ranchi, India
I have 1 pair of slots free. Thinking of just going for the gusto with 2x4gb fb-dimms.

http://www.newegg.com/Product/ProductReview.aspx?Item=N82E16820148128

Seems like the best price I can find by around $30. Presently I have:
2x512mb (stock)
2x1gb
2x2gb

Think it's better to try to match what I have more than go for 4 different sizes of memory? I know there's some performance benefit to having each card matching... Maybe one card with 4x2gb and the other card with 2x1gb? Input appreciated!
 

Umbongo

macrumors 601
Sep 14, 2006
4,934
55
England
The 512mb sticks slow you down and yeah all thoose different capacities will too. I'd probably try and sell the 512s and 1GBs and get another 12GB in the form of 6x2GB. Or get 4x2GB and ditch the 512s. The 1GBs would go in slots 3&4 on board B.
 

tobyg

macrumors 6502a
Aug 31, 2004
528
2
You should really stick with memory designed for your Mac Pro, with the proper sized heat spreaders. NewEgg has a section just for memory for your Mac Pro.
 

Spacedust

macrumors 6502a
May 24, 2009
999
160
Tested memory by myself:

Transcend 1 GB - OK
Samsung 2 GB - OK
Micron 2 GB - OK
Qimonda 2 GB - failed - showed as 1 GB

Now I got 2xSamsung 2 GB, 2xMicron 2GB and 4xTranscend 1 GB.

Samsung and Micron are really hot 80C non stop :/
 

nanofrog

macrumors G4
May 6, 2008
11,719
3
You should really stick with memory designed for your Mac Pro, with the proper sized heat spreaders. NewEgg has a section just for memory for your Mac Pro.
I agree. :)

FB-DIMM runs hot to begin with, but the 80C Spacedust's getting is a result of the smaller heat sink. If you look at iStat data posted on the '06 - '08, it's lower. Closer to the upper 60's C to mid 70's C (load). This is from memory, so a search would be in order. ;)

Personally, I'd go for the heatsinks if possible. The other would work, but as it's hotter, the lifespan may be affected, and it can also affect the temps of other components (increases ambient, and the CPU temps as they share a tunnel design for cooling).
 

ScottishCaptain

macrumors 6502a
Oct 4, 2008
871
474
I second that.

I went through probably 4 packs of various FBDIMM RAM from a local retailer- all of it had the slim heatsinks on it. Every single stick ran at +80*C, which is bloody hot (even though redline is quite a bit higher). And every single stick of RAM eventually failed, causing anything from a machine check exception (and an instant reboot, followed by the motherboard disabling that DIMM), to ECC errors that would show up in System Profiler, and random application crashing.

Eventually, it all got returned, and I ordered some proper RAM from OWC. Showed up a week later, threw it on the riser card, and it's been working 24/7, completely solid, for the past year.

I really don't think FBDIMM's are designed to run that hot. They sort of work, but with the results I witnessed, I'd say it isn't worth the possible trouble you're exposing yourself to with the smaller heatsinks.

-SC
 

nightfly13

macrumors 6502a
Original poster
Jul 17, 2008
679
0
Ranchi, India
Thanks for the input, guys. The mac-labeled memory (on Newegg) was like $20 more expensive, that's why I wondered about this alternative, but yeah, the bigger heatsink makes a lot of sense, I already have ambient heat issues (live in India).

For the record, I had two 1GB pairs from 'techworkx' or something 'by Buffalo' and after 20 reboots and trial and error I realized that 2 of them were bad (sometimes showing up with half their capacity, often not showing up at all). I'm still using the other pair. They were mysteriously cheap, like $50 per pair, 18 months ago, and the company seems to have disappeared shortly afterward. Never manage to return them (bought 'em online in the US, realized they didn't work in India..)

I don't need more memory terribly. I mainly just like that it's getting cheaper and I *could* have a lot more in my machine. After 2-3 days uptime, I do basically run out of 'free' but most of it is hiding in 'inactive'.

I really want my Mac Pro to last me years and years (just upgraded video card for Open GL, am thinking of going up to 8 cores). I'm not in any rush, but I think, eventually, 8x2GB will be a happy medium that I won't regret as too little memory?
 

ungraphic

macrumors 6502a
Nov 15, 2007
596
0
Toronto, Canada
Are the PC2 6400 (DDR2 800) Ram sticks compatible with the 1,1 Mac Pro that requires PC2 5300 (DDR2 667) ? Newegg had an awesome deal on 2x2gb ram in 667mhz a few days ago but theyre not listed anymore, Im guessing either out of stock or something less hopeful. Now I know when i installed some ram on my PC i was using faster clocked ram but it would automatically downclock itself to the correct speed. Would this be the case with the Mac Pro and faster ram?

Thanks!
 

AZREOSpecialist

Suspended
Mar 15, 2009
2,354
1,278
OWC has 4 GB sticks w/ heat spreaders and thermal sensors for the Mac Pro. I have four of these babies in my Quad and they run at the same temperature as the CPU -- approx. 30C. Sounds like something is seriously wrong if the memory is running at 80C.
 

flatfoot

macrumors 65816
Aug 11, 2009
1,010
3
OWC has 4 GB sticks w/ heat spreaders and thermal sensors for the Mac Pro. I have four of these babies in my Quad and they run at the same temperature as the CPU -- approx. 30C. Sounds like something is seriously wrong if the memory is running at 80C.

Is yours a Mac Pro using FB-DIMMs?
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.