ddr3-dimm-ramThe system memory on a typical gaming machine currently ranges from about 2GB to 64GB depending on the age of the machine and the budget. In 2015, its advisable to have at least 8GB installed with the larger number of 64 bit-games available.

Memory prices have generally fallen with a price deflator of about 45% when the industry has been considered over the long term. The increasing cost of foundries seems to have slowed the deflator somewhat.

SDRAM, DDR, DDR2, DDR3 and DDR4 are all 5.25 inches long. This standard uses a pin to block unsuitable memory from being inserted. Each generation specifies a lower operating voltage as smaller feature sizes come into production.

Memory lags behind processors by a couple of generations because of the lower prices that memory can attract. Few have $5+ billion build a new factory. Samsung recently have expanded into 14nm which will benefit the industry generally.

See our page on RAM errors if you believe your memory is faulty. See our page on Hardware Reserved Memory.  See our page on counterfeit DDR3.

JEDEC has specifications for 512 megabit, 1 gigabit, 2 gigabit, 4 gigabit and 8 gigabit DDR3 memory chips. DDR3 memory chips can be 4, 8 or 16 bits wide.  It was not until 2014 when 8 gigabit memory become widely available for severs and 2015 before it became available for gaming enthusiasts.


SDRAM sticks are all 64-bit data but with a varying number of address bits depending on the capacity. Dual channel in ganged mode is 128-bit and unganged it is 64-bit. Using multiple sticks together reduces latency by interleaving motivating triple and quadruple channel memory.


A memory rank is a set of DRAM chips connected to the same chip select, which are therefore accessed simultaneously. In practice all DRAM chips share all of the other command and control signals, and only the chip select pins for each rank are separate (the data pins are shared across ranks).

According to JEDEC, a bank is a block of memory within a DRAM chip while a rank is a block of memory on a module. What used to be called two-sided or two-bank modules will now be called two-rank modules.

The DDR2 memory shown has 16 pieces of 1 gigabit memory on each side to make up 4GB of total memory. The CPU is able to handle 8 ranks meaning this memory will work fine on most machines.


We have been investigating the market for DDR3-1333 and DDR3-1600. eBay, Alibaba and others have many stores selling memory, targeting AMD users. While older Intel platforms are problematic, AMD has better support due to the integrated memory controllers.  AVOID DDR3 memory marketed for AMD AM3 or as High Density, these appear to have been modified from binned or lower SKU memory sticks. High density memory itself is not the problem — its the counterfeiting that is the real issue by selling defective memory as new. See our page on counterfeit DDR3.

Its not hard to change the serial presence detect (SPD) on a DDR3 memory stick. DDR3 use a small 256 byte EEPROM table with the configuration tables. Testing some of these sticks, we found memory sold as DDR3-1600 was actually binned DDR3-1066. The SPD was changed through the SMBUS which is available through the BIOS.

Our Asus M5A99FX PRO R2.0 motherboard has a switch called memOK which forces the BIOS to try more conservative values when memory will not work. Its a kind of failsafe. Our MSI 970A-G43, like most machines, does not have such a switch. Some machines may reset the memory if the machine repeatedly rebooted in rapid succession.

The main motivation for the counterfeiting is driven by large inventories of unsold memory sticks. Demand for DDR3-1066 is so low prices have fallen below $10 per stick. So rather than bundle the memory in sets of 2 or 4, miscreants reprogram the SPD and try to sell them at higher price points. We estimate that as much as 10% of the DDR3 market may be counterfeit. In some areas as much as 70% of memory may be counterfeit.

We have also seen reports of lower capacity memory being reprogrammed to a higher capacity in addition to changing the speed tables to higher values.


Generally speaking, low-density 1GB modules are made with 16 chips, 8 on each side, using 64Mx8 device, while high-density 1GB modules are made with 16 chips, 8 chips on each side, using 128Mx4 device. JEDEC has specifications for 512 megabit, 1 gigabit, 2 gigabit, 4 gigabit and 8 gigabit DDR3 memory chips. DDR3 memory chips can be 4, 8 or 16 bits wide. Unfortunately its not always very clear with RAM reviews as to the specifics of memory organization.

Some manufacturers intentionally block the use of certain memory modules. They use whitelists to force consumers to buy overpriced memory products. We have seen this with Lenovo, Dell and Toshiba etc.


G.SKILL DDR3-2133 SPD tables

We have noticed some low cost DDR3-1333 and DDR3-1600 for those with more limited budgets. 2048MB and 4096MB capacities have been noticed. Intel is fully JEDEC compliant while AMD can use the larger capacity memory chips more easily. We found memory targeting Intel processors that works fine with AMD machines. The memory supports all 6 JEDEC timing speeds. The XMP adds 3 more for a total of 9 entries from the serial presence detect.


Starting in 2012 the desktop market started to see 4 gigabit DDR3 memory become increasingly available which affords 8192MB DIMMs. Prices for 8 GB memory have fallen considerably in 2015.


Samsung has been manufacturing 8 gigabit memory at 20nm since late 2014 and this is the highest size that JEDEC DDR3 covers. So far 16GB sticks have not yet become available for DDR3 machines. We first noticed some 16384MB DDR4 memory in late 2015. We expect a larger selection of high capacity memory choices in 2016.


Many vendors of memory now use heat spreaders attached to the memory sticks.  The industry has been using heat spreaders for marketing as they can be decorated as desired. These are attached with doubled sided tape so its not hard to removed them using a flat heat screwdriver.

Of course there are memory sticks with no heat spreader available. We would have to abandon our Cooler Master Hyper 212 Evo in favor of a water cooling solution or even maybe the noisy OEM fan.


The 1.5 V supply voltage works well with the 90nm fabrication technology used in the original DDR3 chips. DDR3 has been gaining market share and 2011 should see DDR3 finally overtake DDR2 in overall sales. DDR3 allows for higher clock speeds up about 2666 MHz.  The table shows the basic rate, double these values for system speed.

The JEDEC standard speeds are DDR3-800, DDR3-1066, DDR3-1333, DDR3-1600, DDR3-1866 and DDR3-2133. DDR3-457, DDR3-600 and DDR3-760 are common unorthodox speeds which are aimed at overclocking enthusiasts. DDR3L running at 1.35V due to the 30nm lines. This memory will work at 1.5V and until the BIOS can identify that the memory voltages are lower. Lower power consumption is the big benefit for memory. DDR3L will work with any machine fine.


VENDOR/TYPE SIZE CHIPS 400 MHz 533 MHz 666 MHz 800 MHz 933 MHz 1066 MHz
ELPIDA EBJ21UE8BDF0-AE-F 2048MB 16x 1Gb 7-7-7-20
Hynix HMT125U6BFR8C-G7N0 2048MB 16x 1Gb 7-7-7-20
Nanya NT2GC64B88B0NF-CG 2048MB 8x 2Gb 7-7-7-20
Kingston 9905471-004.A00LF 2048MB 16x 1Gb 7-7-7-20
ELPIDA 16JTF25664AZ-1G4F1 2048MB 16x 1Gb 7-7-7-20 9-9-9-24
Kingston DDR3-1333 2048MB 16x 1Gb 7-7-7-20 9-9-9-26
Micron 8KTF25664AZ-1G6M1 2048MB 16x 1Gb 5-5-5-14 7-7-7-19 11-11-11-28
G.SKILL F3-17000CL11-4GBXL 4096MB 16x 2Gb 7-7-7-19 9-9-9-24 11-11-11-28 11-11-11-30
Corsair DDR3-1600 4096MB 16x 2Gb 9-9-9-24 10-10-10-27
Mushkin DDR3-1333 4096MB 16x 2Gb 7-7-7-20 9-9-9-24
Corsair DDR3-1600 8192MB 16x 4Gb 9-9-9-24 10-10-10-27
G.SKILL DDR3-1866 8192MB 16x 4Gb 9-10-9-26
Kingston DDR3-2133 8192MB 16x 4Gb 11-11-11-28 11-12-12-30

On September 22, 2011 Samsung announced volume production of DDR3 their 20nm line. 2 Gb chips are being made first. After that the 4 Gb chip is next in line. Our G.SKILL DDR3-2133 support the XMP extended timing tables devised by Intel to support higher speeds while preserving the JEDEC DDR3 entries untouched.


At present we have several sticks of DDR3 at varying speeds and capacity. Mixing memory can be difficult depending on the memory and the machine capability. Our Elpida memory actually runs at DDR3-1333 speeds even though its rated at DDR3-1066. The Kingston memory may be counterfeit, as it does not work at the specified speeds at all, however its shown from its SPD tables.