Deciphering Hynix RAM options for Westmere 6-core

I would stick to MacSales, Kingston, Crucial, using their memory advisors.

http://eshop.macsales.com/shop/memory/Mac-Pro-Memory

You think it is the same, I think you get what you pay for and you want something that works.

Building a dual processor Xeon and playing the RAM compatible game is worse than on Mac Pro.

Do what you want but be prepared for trouble.

I haven't seen any reference so far that says "low-voltage" DIMMs can be used in a Mac Pro.

1.5v vs 1.65v?
The MP uses 1.5v.
After that, the lower the density, the better.

You can do the large amount of research needed to develop the expertise to specify your memories, but most users buy from a vendor that knows Macs, and can tell them what memories will work in their Mac. A Money-back guarantee ensures the the vendor sends you the correct memories.

Lifetime Warranty is also standard. This encourages Vendors to sell only the highest quality DIMMs.

Your Mac can use up to 8GB DIMMs, but Apple does not yet support 8GB DIMMs (at market prices). That makes it even more important to buy from a Vendor that will support what they sell.

In the US, 8GB DIMMs are being sold by:
Macsales.com (Other World Computing)
DataMemorySystems.com
MemorytoGo.com
RAMJet.com
TransIntl.com

all above except transintl.com (which is showing cheapest 8GB prices at this writing) are shown on:

http://www.ramseeker.com/memory/MacPro_RAM_Upgrade_Kits_DDR3_1333_with_8GBRAM/

Crucial is sometimes listed as a vendor on search sites, but they are not yet ready to ship AND SUPPORT these denser DIMMs at this writing.

Availability of 8GB DIMMs in Europe still appears to be a problem.

Message was edited by: Grant Bennet-Alder

Does Hynix even sell Retail?

Most manufacturers have a 1000-piece or higher minimum order. They are not geared up to sell to you quantity one, accept your credit card, package in small quantities, ship less than a trailer truck load, or handle defects and returns.

Suppose you get the wrong one and it does not work? They have no mechanism to accept returns or give you a refund.

You need a Retailer, with SUPPORT!

You need UNregistered, ECC memory, DDR3-1333 for your Mac Pro 2010 Westmere.
Registered memory is another name for Fully Buffered memory, used in 2008 and previous.
Installing Non-ECC memory in your top-of-the-line Mac Pro will turn off Error Correction, a Bad Idea.

When I enter that in their Server memory selector, "10 parts qualify". They are all 2GB or smaller.

Grant Bennet-Alder wrote:
You need UNregistered, ECC memory, DDR3-1333 for your Mac Pro 2010 Westmere.
Registered memory is another name for Fully Buffered memory, used in 2008 and previous.

Please don't spread misinformation. Registered memory allows for more modules, and more higher capacity memory as well as higher speed memory. It has nothing to do with Fully-Buffered Memory *at all*. Fully Buffered memory was also known as RAMBUS or RDRAM and it is only on pre-2009/pre-nehalem Mac Pro's.

From Apple's Web site:
+"Depending on the processors you choose, the dual-processor Mac Pro uses the following types of memory:+

+2.4GHz quad-core processors: 1066MHz DDR3 ECC SDRAM+
+2.66GHz and 2.93GHz 6-core processors: 1333MHz DDR3 ECC SDRAM+
+8GB DIMMs (48GB or 64GB configurations): 1333MHz DDR3 ECC R-DIMM SDRAM+
+The SDRAM in Mac Pro uses an advanced memory technology that is not only fast, but also reliable. ECC provides this added layer of reliability by automatically correcting memory errors if they occur.+

+Mac Pro supports 8GB registered DIMMs (R-DIMMs) for up to 64GB of memory in 8-Core and 12-Core systems. R-DIMMs cannot be mixed with unregistered DIMMs."+

You won't be able to use 8GB unregistered modules effectively. If you do get them, they will run slower and/or you won't be able to max out your Mac Pro. Not good.

Also, although I haven't been able to prove it, from reading posts in the forums here it appears that the 2GB and 4GB modules that Apple sells are dual ranked, and all 8GB modules are quad ranked. You can't mix rankings in the same memory bank, and putting say, 4GB modules in one bank and 8GB modules in another will unbalance the RAM for each CPU and could lead to other performance issues.

If you are thinking of ever using 8GB modules, you are better off just starting with them.

Unless you can max out with 16GB via 2GB modules for $300 like I was able to 🙂 If I ever need more than 16GB, I won't feel that bad about replacing all my RAM. For now, 16GB is more than enough - between putting my Aperture libraries on an SSD and the 16GB of RAM, Aperture FLIES on my Mac Pro.

Installing Non-ECC memory in your top-of-the-line Mac Pro will turn off Error Correction, a Bad Idea.

On this I do agree - trying to save literally a few dollars by not getting ECC memory is just crazy for computers that average over $3K in price when configured.

Message was edited by: Eric Eskam

Message was edited by: Eric Eskam

Greg Earle wrote:
The interesting thing about a statement like "+Mac Pro supports 8GB registered DIMMs (R-DIMMs) for up to 64GB of memory in 8-Core and 12-Core systems. R-DIMMs cannot be mixed with unregistered DIMMs+." is that, do they mean you can only use R-DIMMs in dual-processor systems? What about my single 6-core Westmere? I would have thought that the memory systems in both the single and dual-processor systems were the same, except for the duals having another full bank of 4 slots. Is there any difference between the 2 banks of 4?

I don't think so. I think they are more referring to the 64GB limit only applying to the two-socket systems. The only thing different, other than one CPU down is four less slots. R-DIMMs should work fine in the single socket machines.

Sorry Eric, I believe you are correct. The FB-DIMM Vs R-DIMM distinction was lost on me.

I stand corrected, and I apologize for spreading confusion on this issue. It was not deliberate.

--------

Memory selection is complex. I continue to advocate for Mac Pro owners to buy from a Vendor that will stand by their product with a money-back guarantee. This is the best defense against getting stuck with expensive modules that do not work.