Quick Guide to DRAM

for Industrial Applications 2019 by SQRAM

What’s the difference between DRAM & Flash?

Cache

SRAM

DRAM

NAND Flash

Ca

pa

city

Sp

ee

d/C

ost

High

Low Large

Small

DRAM (Dynamic Random Access Memory) and Flash are key components in PC systems, but they are

different types of semiconductor products with different speeds/capacity/power-off data storage.

Type DRAM Flash

Location close to CPU data transfer through

PCIe BUS

IC Density low high

Module

Capacity 32~64GB 2~8TB

Speed by ns

(faster than flash) by ms

Power-Off

Status volatile memory:

data will lost if powered off

non-volatile memory:

data can be stored if

powered off

What are the features of DRAM?

High Data Processing Speed

Extremely fast with low latency by nanoseconds(10-9) access time. Much faster than

HDD or SSD data speeds.

Volatile Memory

RAM is a type of volatile memory. It retains its data while powered on, but the data will

vanish once the power is off.

Extremely Fast Transfer

DRAM is closely connected to the CPU with short access time. The system performance will drop if

data is processed directly by storage without DRAM.

Higher Capacity, Better Performance DRAM of higher capacity can process more data to

increase system performance. The more data processed by DRAM, the less HDD processing time.

CPU DRAM HDD

What are the DDR specifications (DDR, DDR2, DDR3, DDR4)?

The prefetch length of DDR SDRAM is 2 bits. On DDR2 the

prefetch length is increased to 4 bits, and on DDR3 and on

DDR 4 it was raised to 8 bits and 16 bits respectively. Higher

prefetch length allows higher data transfer rates and lower

power consumption.

Type DDR DDR2 DDR3/DDR3L DDR4

Prefetch

Length 4 4,8 8 16

Voltage 2.5V/2.6V 1.8V 1.5V/1.35V 1.2V

Data Rate

(MT/s) 266-400

533/667/80

0

1066/1333/

1600/1866

2133/2400/

2666/3200

Density

(by chip)

128Mb-

512Mb

512Mb-

2Gb 1Gb-8Gb 4Gb-32Gb

Organization

(by chip) x4,x8,x16 x4,x8,x16 x4,x8,x16 x4,x8,x16

Capacity

(by module) 128MB-1GB

512MB-

4GB 1GB-16GB 2GB-128GB

DDR

DDR2

DDR3

DDR4

What are the DIMM types and features?

Unbuffered DIMM

Buffered DIMM

Register DIMM: Higher bandwidth and

capacity than UDIMM, suitable for high-

end server markets

Load Reduced DIMM: Extreme capacity

above 32GB and low power consumption

SODIMM for NBs, laptops, box PCs

UDIMM for desktops

ECC DIMM (DIMM with Error

Correcting Code function) for networking, military, telecom, servers

Unbuffered SODIMM (SODIMM)

• Small Outline Dual In-Line Memory Module

Major IC Samsung Inking

Specification PN

Serial No.

ETT IC No Brand

(module vendor brand)

No Specification

No Serial No.

PCB

SDRAM

EEPROM

Resistor

Capacitor

Non-ECC Unbuffered DIMM

• PC DIMM as basic function with best cost

• Non error correction function, neither Register buffer function.

• Cost effective solution

Non-ECC vs. ECC Unbuffered DIMM

Cost-effective DIMM without error

correction function, neither Register

buffer function

Non-ECC memory data path: 64 bits

Applications: PC DIMM with basic

function and cost effectiveness

ECC: Error Correcting Code Memory

ECC memory has one extra unit DRAM IC

on each BANK for Error Correction

ECC memory data path: 72 bit (64 data bits

plus 8 ECC bits for data correction)

Applications: workstations, entry-level

servers

Non-ECC Unbuffered DIMM ECC Unbuffered DIMM

PCB

SDRAM

EEPROM

UDIMM vs. RDIMM (Buffered DIMM)

• Unbuffered Dual In-Line

Memory Module

• Registered Dual In-Line

Memory Module

Register

Capacitor

Resister

Registered DIMM (Buffered DIMM)

Registered DIMM improves signal integrity by having a register on the DIMM to buffer

the address and command signals between each DRAM modules and the system's

memory controller,. It also features an Error Correcting Code function.

Registered memory often has a higher price because of the lower number of units sold

and additional circuitry required.

Register DIMMs achieve higher bandwidth and capacity than unbuffered DIMM.

Application: High-end server market.

Load Reduced DIMM (LR-DIMM)

LRDIMM adds a special memory buffer chip to the bus. Memory buffer chips in the

processer packetize and transmit all data, command and control signals on the LRDIMM.

In this way, the memory buffer handles all the reads and writes to the DRAM chips.

LRDIMMs achieve capacity higher than 32GB and better power saving efficiency.

RDIMM

Memory

Controller

Reg

iste

r CMD/ADDR

/CLK Memory

Controller

Me

mo

ry

Bu

ffe

r

CMD/

ADDR/

CLK

LR-DIMM

DRAM IC Level & Production Flow

Downgraded Unknown production flow, resources

Untested and unmarked

Major Manufacturers Fully tested DRAM and mark IC brand

Vendor: Samsung, Micron, Hynix

Application: High-end market, value conscious

market

ETT : Effectively TesTed Not ully tested DRAM, unmarked

Application: Value memory market

UTT : UnTesTed Not tested and unmarked

Module manufacturing brand

Non-brand

Non-brand

IC inking

Test Package Wafer

IC inking

Test Package Wafer

IC inking

Package Wafer

Package Wafer

Why Choose SQRAM for Industrial Applications?

Industrial and Robust Design

• Original IC with rigorous testing

• Wide temperature of -40~85 °C

• Fixed BOM and 3-year longevity

• Rugged DIMM against shock and extreme vibration

• Optional industrial heatsink

Smart DRAM Management Software

• Manage up to 8 slots of SQRAM memory modules

• Operating temperature monitoring

• Temperatures alert over 65°C

• SPD information and timing table

Customization and Value-Added Service

• Conformal coating/ underfill

• Anti-sulfur protection

• Industrial heatsink

Download SQRAM Manger

Watch Tutorial

SQRAM 32GB DDR4 2666 Unbuffered Memory Solutions

Unbuffered SODIMM ECC Unbuffered DIMM ECC SODIMM Rugged DIMM

SQR-SD4N/ SQR-SD4I 4G~32G

0~85℃/-40~85℃

SQR-UD4N/I(ECC) 4G~32G

0~85℃/-40~85℃

SQR-SD4N/I(ECC) 4G~32G

0~85℃/-40~85℃

SQR-YD4N/I 8G~32G

0~85℃/-40~85℃

Server-Grade Performance / Optional Heatsink Available / Monitoring Software

Data Center Medical Transportation Defense

KC. Liu. Advantech

SQRAM Product Selection https://www.advantech.com/products/memory-

module/sub_memory_module

E-Catalog https://advcloudfiles.advantech.com/ecatalog/2019/0

1250951.pdf

Contact Your Local Sales Offices https://www.advantech.com/contact