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Fyi - 128gb ram
- Thread starter monkeybagel
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Apple's implementation or the Intel chipset itself? The chipset, as far as I'm aware is the same on both Mac Pros - the 5520, i.e Apple didn't use X58 like everyone else did which is why there is RDIMM support. Intel certainly never intended W3500/W3600 to support more than 48GB of RAM in their lifetime either so the memory controller may not be able to address it.
Eitherway looks like no 64GB for UP Mac Pro owners pre-2013.
I really *want* to try it since I have the 4th 16GB DIMM here in my hands, but this all points to there being almost no possibility that it's gonna work - guess I should leave it in the packaging and just return it while I can.
I really *want* to try it since I have the 4th 16GB DIMM here in my hands, but this all points to there being almost no possibility that it's gonna work - guess I should leave it in the packaging and just return it while I can.
According to Intel, the processor can address up to 288GB of RAM, so there is a chance the 16GB may work.
http://ark.intel.com/products/47916/Intel-Xeon-Processor-X5680-12M-Cache-3_33-GHz-6_40-GTs-Intel-QPI
That's the chip for the dual processor configurations. I believe he mentioned having a 3690: http://ark.intel.com/products/52586/Intel-Xeon-Processor-W3690-12M-Cache-3_46-GHz-6_40-GTs-Intel-QPI
The Intel entries are obviously not accurate and don't take into account higher density modules, since we know for a fact this chip can address more than 24 GB.
I'll be interested to read the results of the 64 GB/single proc test in 10.9.
My bad. That is weird as I don't see them predicting the X56xx can address 288GB unless it has a very large number of slots.
Check this though: http://macperformanceguide.com/blog/2013/20130611_9z-OSXMavericks-128GB-in-use.html
It seems OWC has already been testing this theory in 10.9 and while it *does* allow the use of a full 128GB of ram in the dual-cpu models, they couldn't get the machine to even boot with 64GB in the single-cpu config.
Semi-related:
On the topic of using 4 sticks as opposed to 3 (dual vs triple channel)
I read that Mac Pros (Westmere/Nehalems, at least) will address the first three sticks in triple channel mode and only fall back to dual channel if they need to access the fourth stick if they need the extra memory. I'm not 100% sure if this is accurate or not... someone please correct me if it isn't.
Of course, simply having more memory is faster than having triple channel but running out, as tests have proven.
And there's plenty of real world performance tests that show triple channel doesn't make a huge difference.
What I'm wondering is, in situations when your Mac is well below the threshold for needing that 4th stick, does it suffer much in terms of memory performance or is it comparable to plain triple channel mode? (even theoretical?)
On the topic of using 4 sticks as opposed to 3 (dual vs triple channel)
I read that Mac Pros (Westmere/Nehalems, at least) will address the first three sticks in triple channel mode and only fall back to dual channel if they need to access the fourth stick if they need the extra memory. I'm not 100% sure if this is accurate or not... someone please correct me if it isn't.
Of course, simply having more memory is faster than having triple channel but running out, as tests have proven.
And there's plenty of real world performance tests that show triple channel doesn't make a huge difference.
What I'm wondering is, in situations when your Mac is well below the threshold for needing that 4th stick, does it suffer much in terms of memory performance or is it comparable to plain triple channel mode? (even theoretical?)
Check this though: http://macperformanceguide.com/blog/2013/20130611_9z-OSXMavericks-128GB-in-use.html
It seems OWC has already been testing this theory in 10.9 and while it *does* allow the use of a full 128GB of ram in the dual-cpu models, they couldn't get the machine to even boot with 64GB in the single-cpu config.
I wonder why it will not even boot with 4x16GB? I know the 2010 Mac mini doesn't "support" 16GB, however with one type of RAM configuration it boots and works every time. I wonder if there is a similar case with the single processor Mac Pro? If it just finding the right combination.
On my 2012, I have to admit, it was a very easy upgrade. Everything turned on and worked perfectly the first try.
5600 series certified for 18x16GB. That is 3 channels x 3 DIMMs x 2 CPUs, as in 288GB can be addressed by one CPU as it can access another's memory.
5500 series were only certified for 144GB as 16GB DIMMs weren't available in Q1 2009, they work with 384GB of LR-DIMMs too.
32GB's came along it their lifetime and LR-DIMM support added to boards allowing 384GB RAM (12x32GB), but Intel don't change the original certified numbers, board makers did though.
3500/3600 were certified for 6x4GB as 8GB unbuffered weren't available then. Same as the i7s. X58 Chipset does not allow you to use RDIMMs so these CPUs can't typically ever get more than 48GB to address.
So the 3500/3600/i7s on a Mac Pro seem to use a single socket on 5520 chipset allowing the memory controller to work with RDIMMs, so you can use 16GB DIMMs.
I guess the CPU can't handle more than 48GB, as in Intel did enable that much as they foresaw 8GB DIMMs coming in their lifetime, but not 16GB as to Intel they were only going to get paired with X58 chipsets and 16GB unbuffered wasn't likely in the CPU's lifetime. Or you can't access more than 16GB on one memory channel. I'd be curious to see 16GBx3 and 8GBx1 tested, obviously you'd need all DDR3 RDIMMs of the same voltage.
Well, I can't test that, but I couldn't resist at least *trying* my 4th 16GB one before I send it back. I got the exact same results that OWC reported - good boot screen w/Apple logo comes up, but once the boot process starts it just reboots and reboots and reboots. I'm trying this on 10.8.5 but from that blog post referred to earlier, OWC tried this on 10.9 with the same results.
Well what I would say to someone who will get real productivity or functionality out of more memory is to trade their single CPU system for a dual CPU system. You can get a 2010 for $1,500 and a 2009 for under $1,200. Two W5580s (3.2GHz) can be had for under $400. Bit more on the power bill and some the hassle, but 2 more cores and more memory capacity for a lot less than a new Mac Pro upgrade.
You could probably do it for $0 total cost, maybe even make a profit, by buying a 2009 and the two CPUs and doing the firmware update then selling a 6-core system because consumers aren't considering it as a real option.
I don't think this statement is accurate. The following quote is from the OWC website:
It clearly indicates that they cannot be mixed with Apple's unbuffered memory modules. Besides I haven't seen any 16GB DDR3 unbuffered (ECC or non-ECC) memory modules on the market yet. See the discussion of this topic here.
Well what I would say to someone who will get real productivity or functionality out of more memory is to trade their single CPU system for a dual CPU system. You can get a 2010 for $1,500 and a 2009 for under $1,200. Two W5580s (3.2GHz) can be had for under $400. Bit more on the power bill and some the hassle, but 2 more cores and more memory capacity for a lot less than a new Mac Pro upgrade.
You could probably do it for $0 total cost, maybe even make a profit, by buying a 2009 and the two CPUs and doing the firmware update then selling a 6-core system because consumers aren't considering it as a real option.
Good point really - I'd love to do that and keep my current speed and go to (2) X5690's rather than the single W3690 I have now but those are still *crazy* expensive and the reality is don't need all those cores. Thankfully the Amazon return process is super-easy so I resisted the urge and just returned the 4th 16GB DIMM
Just wow on that much ram. Jealous doesn't even begin to state how I feel. That is freaking awesome. Can I ask what you use that mush for? Video or scientific number crunching?
I use it to replicate physical networks and servers for testing. I heavily rely on VMware products and that much RAM allows me to replicate many complex physical networks before they are put into production.
OS X has been very stable in this testing. I wasn't sure how it would fare when being pushed to the limits on memory load as I have not tried before, but I was happily surprised. 10.9 has been rock solid.
Flow,
Interesting link you've provided. If I were to purchase 8 x 16GB DDR3-1333 RAM from DMS (which is certified), it would cost me $1352 verses $1730 from OWC. That is a savings of $378! Why is the OWC memory so high in price? Have you purchased RAM from DMS before...with success? As usual, you help is greatly appreciated!
Frank
