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My MB has a ceiling of 32GB, but only 2 DIMM slots

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  • Laptops
  • DIMM
  • Memory
Last response: in Memory
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October 16, 2014 9:27:52 PM

Is there such a thing as a single memory SO-DIMM module of 16GB ram? I need two to reach the max memory in my laptop. I need PC3 10600 CL9 1.5V.

More about : ceiling 32gb dimm slots

a b D Laptop
a b } Memory
October 16, 2014 9:38:40 PM

For DDR3 nope, which is why it's weird since even newegg TV had a mobo that said it supported 32GB with only two slots.

Only DDR4 will eventually have 16GB DiMMS.
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October 17, 2014 8:14:22 AM

TechyInAZ said:
For DDR3 nope, which is why it's weird since even newegg TV had a mobo that said it supported 32GB with only two slots.

Only DDR4 will eventually have 16GB DiMMS.


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October 17, 2014 8:15:28 AM

Thanks Techy, I expected as much, as I've been all over the internet searching. Thanks for your quick response!
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a b D Laptop
a b } Memory
October 17, 2014 9:01:58 AM

Np, yeah I've also had trouble with google so I know your pain. :) 
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a b D Laptop
a c 145 } Memory
October 17, 2014 7:03:19 PM

PhiSchmo said:
Is there such a thing as a single memory SO-DIMM module of 16GB ram? I need two to reach the max memory in my laptop. I need PC3 10600 CL9 1.5V.


Yes there is, but they are very, very hard to find. The most popular DIMM manufacturers do not manufacture DDR3 UDIMMs over 8GiB right now. There are a few niche manufactures that do, but be prepared to spend a lot of money and deal with potential compatibility issues.

Many motherboards support 16GiB UDIMMs at the firmware level, meaning that the board should boot just fine if a fully JEDEC compliant module of that capacity were inserted. However, only a few such modules exist and they've only been available for a scant few months.

Here's why.

Unbuffered DIMMs (UDIMM) used in most desktops are typically constructed of 8 x 8-bit DRAM ICs per rank. When concatenated, this forms a standard 64 bit wide DRAM bus. Consumer modules will have either one or two ranks per DIMM (typically on either side of the DIMM). If the DRAM chips are 4 gigabits in capacity each (the standard right now), this yields 4 gigabytes of capacity per rank (4 gigabits per chip * 8 chips per rank / 8 bits per byte) and can be used to construct either a single-sided 4GiB DIMM or a dual-sided 8GiB DIMM. 4 gigabit DRAM ICs are fairly new and older 2 gigabit DRAM ICs are still popular. 8 gigabit DRAM ICs are very new having just become commercially available recently but they are slower and thicker so DIMM manufacturers are reluctant to use them in personal computers.

Laptop memory is designed to fit within a smaller space, so real estate on the PCB is precious. Many SO-DIMM modules use 4x16-bit DRAM ICs to form the same 64 bit data bus as 8x8-bit DRAM ICs. In this case, the use of 4 gigabit DRAM ICs would provide only 2GiB per rank. Given that 8 gigabit DRAM ICs have a larger footprint than their more common 4 gigabit DRAM ICs it's most likely going to be even harder to design a SO-DIMM that uses 8x8-bit 8 gigabit DRAM ICs on each side of the PCB (8 gigabytes per rank, one rank per side) while meeting the tight size constraints of the SO-DIMM formfactor.

DDR4 was designed with the methods used to manufacture the current 8 gigabit DDR3 DRAM ICs in mind (they use a stacked die). Coupled with greater native capacities, it's expected that 16GiB DIMMs will be readily available for DDR4.
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