Difference between revisions of "Memory Upgrade for your PC"

Revision as of 16:48, 26 February 2019

DDR2 / PC2 - 240 pins (200 for SO-DIMM)

DDR3 / PC3 - 240 pins (204 for SO-DIMM) not compatible with DDR2

DDR4 / PC4 -

Error Correcting Code (ECC) RAM is mostly used in servers and aims to detect and correct data corruption. Most desktop and laptop computers will not run it.

Numbers on back of RAM explained.

DDR4-3200 - 3200 refers to the clock frequency

SO-DIMM - Small Outline DIMM in laptops and small form factor computers

DDR - Double Data Rate

DDR3-1600 is also PC3-12800 - generation of the RAM and its transfer speed. DDR3-1600 RAM operates at 1600 MT/s or the same as PC3-12800 operates at 12800 MB/s

S or SoDimm

12800S - the S on the end refers to size, it is a smaller SoDimm or form factor type ram commonly used in laptop computers, all-in-one computers, etc. Sometimes the memory might say 12800 SoDimm rather than 12800S. Same thing.

12800 - without the S should be full sized 240 pin memory. Be careful because sometimes instead of having the S at the end of the number they leave it off, and then somewhere else state that it is SoDIMM or 200/204 pin.

Some Examples

example (1):

PC3 10600S-9-11-F3

• PC3 (same as DDR3)
• 10600 (bandwidth in MB/s),
• S (stands for SODIMM, it's RAM for laptops),
• 9 (CAS latency).
• 11 is the SPD Revision or a way the memory communicates to BIOS
• F3 is the Gerber Revision or changes in the printed circuit board

If it says PC3L it can operate at 1.35V or 1.5V

L is for low voltage. Don't mix L and non-L. If the laptop requires L then use L. DDR3L is a dual voltage capable memory SoDIMM, which supports operation at both 1.5V and 1.35V. DDR3L is also pin-compatible with DDR3. DDR3 is a single voltage capable memory SoDIMM, which supports 1.5V operation only.

example (2):

PC3L-12800S DDR3 1600MHz 204pin So-Dimm

Low voltage DDR3 ram

Operating System Limitation

The operating system you are running can affect the maximum amount of RAM you can use in your computer. The maximum RAM limit for 32-bit Windows 7 edition is 4 GB. Here are the limits for other Windows 7 editions:

• Windows 7 Home Basic: 8 GB
• Windows 7 Home Premium: 16 GB
• Windows 7 Professional: 192 GB
• Enterprise: 192 GB
• Ultimate: 192 GB

For Windows 8.1 32-bit, the limit is 4 GB of RAM. For the other Windows 8 editions:

• Windows 8.1 (64-bit): 128 GB
• Windows 8.1 Professional (64-bit): 512 GB
• Windows 8.1 Enterprise (64-bit): 512 GB

Caution on mixing memory of different manufacturers or types

Due to the variety of possible configurations, some motherboards might not be able to properly configure memory if the array of dual in-line memory modules (DIMMs) contains a DIMM that is not from the same manufacturer, has a different CAS latency value, or has a different density value (high and low used together).

• Best to use memory together of the same size, model, and manufacturer

You can never mix DDR with DDR2, or DDR2 with DDR3, and so on (they won't even fit in the same slots). Use ram that has the same CAS latency, timings, and voltage.

If you mix memory that is of a different speed, such as mixing a DDR3-1333 with a DDR3-1600 as long as they have the same CAS latency, timings, and operate at the same voltage, it will probably work, however, the system will clock memory at the lowest of the two speeds. the memory will only run at the speed of the slowest DIMM, unless you overclock the slower one which will probably result in instability.