ram for 2010 Mac Pro 2.8 Quad, 1066 or 1333?

[Draeconis]

Yes. All 2010 Mac Pros actually ship with 1333MHz memory and that is the only speed supported officially.

That's a little incorrect mate, from Apple''s own Mac Pro page;

Depending on the processor you choose, the single-processor Mac Pro uses the following types of memory:

2.8GHz and 3.2GHz quad-core processors: 1066MHz DDR3 ECC SDRAM
3.33GHz 6-core processor: 1333MHz DDR3 ECC SDRAM
8GB DIMMs (24GB or 32GB configurations): 1333MHz DDR3 ECC R-DIMM SDRAM

You can put 1333MHz DDR3 ECC SDRAM in the Quad-Core Mac Pro, but there won't be a massive benefit from it.

 

[Umbongo]

That's a little incorrect mate, from Apple''s own Mac Pro page;

When I posted that statement 6 months ago Apple were shipping 1333MHz DIMMs throughout the range. This is page 43 from the Mac Pro manual:

It is also reiterated in the document: "Mac Pro (Early 2009 and Mid 2010) - Memory DIMMs - Replacement Instructions".

It is cheaper and simpler for Apple to only buy and use one type of DIMM which is what they did and I assume still do.

 

[dyn]

Yes. All 2010 Mac Pros actually ship with 1333MHz memory and that is the only speed supported officially.

Not the entire story there which makes your reply a bit misleading as well as your second reply. Some of the cpu options for the single cpu Mac (aka the quad core) only support 1066 MHz and thus memory will run at 1066 MHz. The other options do support 1333MHz. Since memory is backwards compatible (1333 MHz will work in the quad core but it will run at 1066 MHz since that is what the cpu supports) it makes it very easy for Apple: they just buy loads and loads of 1333 MHz modules because they can stick it in any Mac Pro. They could go for 1066 MHz modules too because they'll work with the other cpu options too only this will be a decrease in performance for most of the offered cpu options. A very good reason to go with 1333 instead of 1066MHz memory.

In short: 1333MHz modules will work in all the 2010 Mac Pro versions (which is why Apple is using those) but the cpu will decide whether it will run at 1066 or at 1333 MHz. The safest option for any 2010 Mac Pro would be 1333 MHz memory.

 

[Draeconis]

When I posted that statement 6 months ago Apple were shipping 1333MHz DIMMs throughout the range. This is page 43 from the Mac Pro manual:

snip

It is also reiterated in the document: "Mac Pro (Early 2009 and Mid 2010) - Memory DIMMs - Replacement Instructions".

It is cheaper and simpler for Apple to only buy and use one type of DIMM which is what they did and I assume still do.

Ah I see, I did take a look at the RAM in my MacPro5,1 and I couldn't see 1066Mhz or 1333Mhz written on it anywhere, but I'll take your word for it