Does the 5960x Support 16GB RAM modules?

[LHibo]

Hi There

I've learnt from threads on here I'm limited to 64GB on my 5960x which is fine BUT what I want to know is there a limit to RAM module size?

What I mean is I want to get the corsair platinum dominator kit, but I can get it in either 8x 8GB or also available is the 4x 16GB, but looking at the compatibility charts from the MSI Mobo I'm looking at and others the only 16GB modules supported are ECC server type stuff.

If my research is correct, it's easier (well better chance of stability) to overclock memory with fewer dimms, thus the 4x 16GB would be better, plus I think it'd look nicer,, but I don't know if the reason I can't find on any compatibility listing the Corsair Dom Plat kits using 16GB modules is because inherently the i7 chips on a x99 platform etc does not support that larger size of DIMM?

So in theory should 4x 16GB be OK on the 5960x? or is it I have to go the 8x 8GB route??

Any help you can give helping me find the answer would be gratefully received, My google-fu has let me down so far

All the best,

Lee

[AJana1]

Hello Hiboson,

Please take a look at http://ark.intel.com/products/82930/Intel-Core-i7-5960X-Processor-Extreme-Edition-20M-Cache-up-to-3_50-GHz?q=%20i7%205960X Intel® Core™ i7-5960X Processor Extreme Edition (20M Cache, up to 3.50 GHz) Specifications, this processor does not support ECC memory modules!

Please refer to http://www.intel.com/content/www/us/en/processors/core/core-i7-lga2011-3-datasheet-vol-1.html Intel® Core™ i7 Processor for LGA2011-3 Socket Datasheet, Vol. 1, turn to page 11, where I found something important,

Supports four DDR4 channels

Unbuffered DDR4 DIMMs supported

Memory DDR4 data transfer rates of 1600 MT/s, 1866 MT/s, and 2133 MT/s

64-bit wide channels

2Gb and 4Gb DDR4 DRAM technologies supported for these devices; - UDIMMs x8, x16

Up to 4 ranks supported per memory channel, 1, 2, or 4 ranks per DIMM...

From the above information, this processor does support 16GB memory modules, and it is the maximum memory modules size, calculated from 4Gb x (64/8) x 4 / 8 = 16GB, where presuming that each DDR4 DRAM device is 4Gb, because the channel size is 64-bit, so choosing the smallest device would gain the maximum memory size, x8 is chosen. Then each rank could comprise of 64/8 = 8 DRAM devices, this processor supports 4 ranks per DIMM at maximum, so 4Gb x 8 devices-per-rank x 4 rank / 8 bits-per-byte = 16GB. Such a memory module would have 32 such identical chips on it. Fulfilling the all four channels with such memory modules would implement the maximum 64GB system memory.

Best Regards,

Aaron Janagewen

[LHibo]

Hi Aaron

Thanks for getting back to me as this has melted my brain lol sooo many numbers, I had read the 5960x spec sheet but with my knowledge level/abilities figured out that max was 64GB lol As for your calculations I will take your word for it I'm lost , I hope to understand it one day but right now my sleep deprived brain is refusing

So in theory 16GB sticks would work which is cool, was looking at the Corsair CMD64GX4M4A2666C15 or the Corsair CMD64GX4M4B2800C14 and running them on a X99A SLI PLUS mobo. Still routing through trying to find definitive answers if they would work on that board, I've learnt from my adventures that it amazing how many RAM modules arn't compatible with mobos or should I say not being shown as not compatible! It'd be nice on motherboard compatibility listings if it showed you what they tested and know don't work as well as a list of what does, so I would know if it's definitely not going to work or just never been tested

Again, thanks for your help you've been amazing

All the best,

Lee

[AJana1]

Hello Hiboson,

Please refer to http://download.msi.com/archive/mnu_exe/E7885v1.1.zip manual of MSI X99A SLI PLUS, turn to page 1-4, where it says it supports DDR4 memory up to 128GB, providing 8 DIMM slots. But Core i7-5960x might only support up to 64GB. You could configure 64GB system memory in 8GB x 8 or 16GB x 4. The configuration of 16GB x8 might halt your system with PC speaker beeping up. For the latter configuration, remember that for each channel only one memory module could be put, please turn to page 1-16 for details. Please also take a look at http://www.corsair.com/~/media/Corsair/download-files/manuals/dram/DDR4-Compatibility.pdf compatibility paper of Corsair CMD64GX4M4A2666C15, most high end mainboards based x99 chipsets are supported. But you'd better contact MSI and Corsair for the desired information before customising your computer. Good luck!

Best Regards,

Aaron Janagewen

[KTran10]

Here is the specs of MSI board. I agree with Aaron to contact MSI and ask them what 16GB DIMM had been tested on this board. Micron DRAM behave better with Haswell, a verify with Crucial what DRAM chip they use

• Due to chipset resource usage, the system will only detect up to 127+ GB of

memory (not full 128 GB) when all DIMM slots have 16GB memory modules

installed.

[AJana1]

langtu, I believe your idea is positive! But can you promise all the users could successfully configure their system with 127+ GB, when using core i7-5960x?

Due to chipset resource usage, the system will only detect up to 127+ GB of memory (not full 128 GB) when all DIMM slots have 16GB memory modules

OK, the reserved space is called memory hole. During the days when 8086 is popular, memory addressing space between 640KB and 1MB is a hole; when 80286 is introduced, there is another hole between 15MB and 16MB; when 80386 is introduced, the third hole between 3GB and 4GB is also introduced; when Pentium Pro was introduced, it digs a fourth hole between 35GB through 36GB. If all those four holes have been re-mapped, users would hardly find their existence. I believe your system does not remap the fourth hole in 35GB through 36GB, so you could not fully utilise the entire 128GB system memory.

I wish Core i7-5960x could support system memory up to 128GB, but I should follow what intel specs says, 64GB rather than 128GB!

[LHibo]

Thanks for your replies

I've asked over on the MSI forums what has been tested and is "Not Compatible" and will it accept the Corsair Dom Plat 16GB DIMMs etc, I'm going to go for the safe 64GB of RAM in my system, safe in terms of the stated limit on the 5960x specs and WAY safer on my wallet

I had already checked the Corsair DDR4 compatibility listings but unfortunately they don't have the X99A SLI Plus listed only the X99S SLI Plus, I would hope they'd be same compatibility but as it's not definitively listed the doubt train is have a good journey in my head lol

Unfortunately no one has answered my questions over there yet, hopefully soon

I never thought RAM would be the last sticking point in this build, if I thought finding out compatibility etc would have been so hard would have started that research journey sooner, want to get all my bits together this weekend and validate all my parts so if any are DOA I shouldn't have any issues with returns. So I hope the power of the internet supplies me with a good answer by my buying deadline tomorrow, otherwise I might have to go for the safe bet the CMD64GX4M8A2666C15 a 8x 8GB option, this atleast is listed on the corsair compatibility list as OK with the X99S version and all there other X99 boards listed on it so would feel quite confident that one would be ok. Ideally would love to do the CMD64GX4M4B2800C14 (or even CMD64GX4M4A2666C15 or at a push the CMD64GX4M4A2400C14) which I've stated before as these are all 4x 16GB versions. It's just finding out now if anyone has tried these combos to see if there is compatibility

Again thanks for you help

All the best,

Lee

[KTran10]

CPU 5960 support 16GB DIMM, other variables are the motherboard and memory tested