ddr3ram ddr3 ram

[redape2050]

Pls help . I have a PC with 1600Mhz ddd3 ram. In thse photos what is the number in bottom right corner mean(1228 ,1334,1435)? I have an 1435 ddr3 ram! i'm looking to add some ram but I haven't find any ram that matches these numbers in my ram. is it mean stock clock speed? I looked into somany online article none of them mentioned it pls help me

[Crunchy Dragon]

I'm not sure what those numbers are, but it isn't clock speed.

 

In the first line, you see PC3-12800S, which denotes type of RAM(DDR3) and RAM speed.

[Sakkura]

8 minutes ago, Crunchy Dragon said:

In the first line, you see PC3-12800S, which denotes type of RAM(DDR3) and RAM speed.

And 12800 is the speed in MB/s. Converted to data rate, it's equivalent to 1600 MT/s. So it's definitely all DDR3-1600.

[Whiro]

13 minutes ago, redape2050 said:

I looked into somany online article none of them mentioned it pls help me

This numbers have nothing to do with your ram , most likely is some sort of batch number or something similar. Check this out

 

[mariushm]

PC3L-12800S

PC3 = DDR3

L = Low voltage DDR3, means it only needs 1.35v instead of 1.5v to run (but it's relatively safe to work with 1.5v if your computer isn't smart enough to reduce the voltage)

12800 = "performance rating"

S = probably Single Rank ... D would be Dual Rank ... just how the tiny chips are arranged on the sticks ... some devices don't like dual rank memory (may work with 2 memory sticks but not 4, or may run with 4 dual rank only at lower frequencies)

 

The speed is specified by that PC-12800 code.

The number tells you the "performance rating" of the memory stick.

 

If you're curious it's calculated like this:

 

There's 64 data pins on every memory stick, and on each tick (Hz), there's 2 bits of information put on each pin, so you have 128 bits per Hz, or 16 bytes per Hz.

A memory stick that's advertised as 1600 Mhz will actually run at half that frequency, 800 Mhz. 

So if you multiply 16 bytes with 800.000.000 Hz, you get 12,800,000,000 bytes/s  or 12800 MB per second...

 

So

1066 Mhz memory = 16 x 533.33 = ~8528  => PC3-8500  (rounded down for simplicity)

1333 Mhz = 16 x 666 = ~10667 = PC3-10600

and so on ...

 

You can find all the codes for DDR3 here: https://en.wikipedia.org/wiki/DDR3_SDRAM#Modules

 

The actual numbers on the chips can be used to also determine ONE guaranteed  memory frequency. Well, it's the part number, which points you to a datasheet where you'll get information about how to decode the part number.

 

The chips will run at  the standard voltage (ex 1.5v for ddr3, 1.35v for ddr3l, or 1.2v for ddr4) at that frequency printed on it.

But, for example, memory manufacturer may have more orders for ddr3 1333 mhz memory and he may simply use ddr3 1600 chips on the stick and sell the stick as 1333 mhz (in such case you get free overclocking room)

 

Or, manufacturer may take thousands of tiny chips and bin them... that means overclock each one individually and determine how safe it is to use at a frequency higher than the one guaranteed by the ram chip maker. 

So, the manufacturer may take 8-16 chips that were guaranteed by let's say Hynix or Samsung for 1600 Mhz at 1.5v, but they tested at 1.65v and found they work at up to 1900-1950 Mhz, so they'll advertise them as 1.65v 1866 Mhz  and give them long warranty and so on. Basically, a factory overclock with all the safeties.

 

So the printed text on the tiny chips may not always match what the manufacturer of the stick actually guarantees the stick is capable of.

 

[redape2050]

Thanks guys . guys really appreciate it. I never got any good replys in any other community's some guys in others community's said it's clockspeed lol 

[Whiro]

22 minutes ago, redape2050 said:

Thanks guys . guys really appreciate it. I never got any good replys in any other community's some guys in others community's said it's clockspeed lol 

Because this is the best forum