RAM and Mother Board considerations for i5 and i7

The question has been posed "How do I get the most RAM value for my new i7 based computer?" Somewhat surprisingly there is no fixed answer to that question because it involves an ever developing competitive environment.

When the i5 and i7 were first announced the i5 was a "2-channel" memory processor and the i7 was a "3-channel" memory processor. Both of these CPU chips had on-chip memory processing capability but required different memory sticks albeit from the same generation (DDR3). The i5 required the 2-channel mother board and the i7 required the 3-channel mother board.

The obvious result of this was that i7 motherboards were equipped with RAM sockets in groups of three modules (usually 6) and the i5 mother board had groups of 2 sockets (usually 4). The gave an i5 machine with a 16GB capacity as the sockets were limited to 4GB memory modules and there were 4 of them and an i7 machine with a maximum capacity of 24GB of RAM. All of this RAM is non-ECC Registered RAM and usually un-buffered as well.

The i7 triple-channel mother boards remain at 24GB maximum with the exception of some server class dual CPU mother boards which can accomodate up to 96GB of RAM (or higher) but which require server class hardware and error correcting memory to reach these levels.

The new "Sandybridge" i5 and i7 processors which use dual channel DDR3 memory and a new motherboard chipset, can provide 16GB capacity i7. Although this is the chip set that was infamous for the production flaw which cost Intel dearly to repair and replace, that has all been workked out now and the Sandybridge product is flowing again.

The Sandybridge chip set allows 16GB of memory on an i7 mother board (i7-2600) and will allow 32GB if there is ever an 8GB module that is non-ECC available. There are currently 8GB modules but they are server class ECC Registered with a price tag in the $350+ range. The i5-2500 CPU uses the Sandybridge boards and still allows 16GB of RAM to be loaded on the mother board.

Is 16GB enough RAM for Hauptwerk ? The answer in most cases is a resounding yes! There are a few sample sets that can require more memory and there will certainly be more of them in the future. So while discussing the RAM requirements for your computer, it should be kept in mind that Hauptwerk recommends that only 66% of the available ram be used to prevent the operating system from trying to stash RAM information on the much slower hard drive. Even the solid-state drives are not as fast as RAM. This can cause a poping and drop-outs in the ASIO audio stream. There are some i7 24GB machines which do not seem to have this issue but the jury is still out. This means that a computer with 16GB of RAM installed, can most likely only utilize 12GB of that memory for Hauptwerk and sample sets. This now means that no, 16GB is not enough for some sample sets. The 24GB RAM reduces to 18GB which in most cases IS enough RAM for Hauptwerk and its professional ASIO audio stream.

The conclusion to this is yet to be written but the recommendation for June 2011 is that if you need more that 12GB and less than 17GB for any sample set you plan to own, that you use the 24GB i7, triple-channel technology. If 12GB is adequate for your current sample sets, then the 16GB Sandybridge motherboards are an excellent choice. Someday there will be 8GB RAM modules but whether they will work in the present mother boards is unknown.

-TJG-