RAM speed -- what's up with 1600Mhz only?

[NoCoErik]

First post, probably not last! I'm tired of Apple dragging feet on a "real" new machine. Slogging along on my 2.66 Quad-core Xeon machine. Need to build one for SPEED and STABILITY. I'm putting together a parts list based on http://tonymacx86.blogspot.com/search/label/CustoMac
and most likely the Socket 2011 Pro Build. Building it to process RAW still images in huge batches (think 2000 - 4000 per batch from a 5DIII) and HD video editing from DSLR of today, and cameras like the BlackMagic Cinema or Sony NEX-FS700 or similar heavy hitters.

To the point: RAM.
All the recommended RAM is 1600Mhz.

Several known compatible motherboards can handle speeds much higher, like

http://www.newegg.com/Product/Product.aspx?Item=N82E16813128531&Tpk=GA-X79-UD5
or
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131801&Tpk=ASUS%20Sabertooth%20X79%20LGA%202011
(from the build at http://www.tonymacx86.com/user-buil...pro-3930k-gtx670-sabertooth-x79-56k-warn.html)

However, the Intel Core i7 CPU options listed either say they support 1600Mhz, or something more vague like "Integrated Four Channel DDR3 Memory Controller" without any mention of speed.

Is there a cap of 1600Mhz on RAM that these Hackintosh machines will take? Or is it a budgetary reason? Or maybe that one can spend more $$ and get little gain, therefore alternates are not suggested.

I'll follow with a shopping list based on what I've found here that users say works. Just looking at the RAM thing separately.

 

[BitterMelon]

Bugetary reasons I'd say. Afaik, there isn't much gain in running faster RAM. And no, there is no specific cap needed for OS X, this is the same for PCs (and indeed servers) in general.

 

[Asus-Freak]

I think the cap is 2400 (platform not OS). I run mine at 2133 and the performance gain is quite noticeable..

 

[NoCoErik]

Hmmm. I see. I think.

I was thinking http://www.newegg.com/Product/Product.aspx?Item=N82E16813131801&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-_-na-_-na-_-na&AID=10446076&PID=4902415&SID=
for the motherboard, which caps out at 1866Mhz it seems.

Does the CPU set have to support a specific speed too? I'm not sure why they list 1600Mhz on some, and vague on others.

 

[Going Bald]

Is there a cap of 1600Mhz on RAM that these Hackintosh machines will take? Or is it a budgetary reason? Or maybe that one can spend more $$ and get little gain, therefore alternates are not suggested.

I'll follow with a shopping list based on what I've found here that users say works. Just looking at the RAM thing separately.

The reason for the 1600MHz is that it is the default memory bus speed for most Intel Ivy Bridge CPUs. If you go to ark.intel.com and look at the official specs of the CPU, in the Memory section you will see something like this one for the 3930K:

[TR="class: infoSection"] [TR="class: tech even odd"] [TR="class: tech"] [TR="class: tech even odd"] [TR="class: tech"] [TR="class: even odd"]

Memory Specifications
Max Memory Size (dependent on memory type)	64 GB
Memory Types	DDR3-1066/1333/1600
# of Memory Channels	4
Max Memory Bandwidth	51.2 GB/s
ECC Memory Supported	No

 

[NoCoErik]

Going Bald,

Got it. I did go to the link you posted, and I see that now. I had a hunch that 1600Mhz standard had a reason. That's it.

One question down… about 100 more to solve (and 100 yet to arise -- that I'll need to find out).

Thanks!