What is DDR3L?

[prmtvr]

The question says it all.

 

[timarp000]

The question says it all.

ddr3l is ddr3 memory but has much lower voltages, (eg.1.35v & 1.25v)


The new 3rd gen intel core processors(ivybridge) support ddr3l.


lower voltages mean less heat and will increase the life of your module.



ddr3l is usuall $5-$10 more than ddr3

 

[prmtvr]

Best answer selected by prmtvr.

 

[jaquith]

To be clear, DDR3L (1.35v) RAM works on Sandy Bridge, Ivy Bridge and AMD FX CPUs. I use 32GB of DDR3L Corsair on my SB-E/LGA 2011 and love them!

 

[dougwh]

Also the lower the operating voltage, (1.5v, 1.35v, 1.25v) the faster the memory can theoretically operate because the transition from a zero to a one state requires less voltage shift. It takes less time to go from zero to 1.25 v than it does to go from zero to 1.5v. So the memory cell comes ready sooner.

 

[thegamer298]

Also the lower the operating voltage, (1.5v, 1.35v, 1.25v) the faster the memory can theoretically operate because the transition from a zero to a one state requires less voltage shift. It takes less time to go from zero to 1.25 v than it does to go from zero to 1.5v. So the memory cell comes ready sooner.

Not really, if the latency and frequency are the same then almost no performance difference.

 

[tedraab]

The question says it all.

ddr3l is ddr3 memory but has much lower voltages, (eg.1.35v & 1.25v)


The new 3rd gen intel core processors(ivybridge) support ddr3l.


lower voltages mean less heat and will increase the life of your module.



ddr3l is usuall $5-$10 more than ddr3

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OK, my new Lenovo Thinkpad L440 comes with one DDR3L (4GB) and one open slot. I have a DDR3 (4GB) from an earlier Lenovo Thinkpad. What are the pros and cons of installing the DDR3 module in the open slot (it will fit).

Second, I see that the memory upgrade sold by Crucial Tech for the Thinkpad L440 is DDR3. I discussed this with them and they insisted that their DDR3 modules (1.35v) will operate perfectly fine in the L440. What do you think?

 

[revnu]

Also the lower the operating voltage, (1.5v, 1.35v, 1.25v) the faster the memory can theoretically operate because the transition from a zero to a one state requires less voltage shift. It takes less time to go from zero to 1.25 v than it does to go from zero to 1.5v. So the memory cell comes ready sooner.

Not really, if the latency and frequency are the same then almost no performance difference.

You didnt understand the point that he made.....of course if the latency and frequency are the same the performance is the same BUT(!) if the transition from digital-LOW to digital-HIGH is shorter you can get better latency......if you wont believe that read some stuff about digatal-design

 

[Pinhedd]

Also the lower the operating voltage, (1.5v, 1.35v, 1.25v) the faster the memory can theoretically operate because the transition from a zero to a one state requires less voltage shift. It takes less time to go from zero to 1.25 v than it does to go from zero to 1.5v. So the memory cell comes ready sooner.

It's the other way around.

The limitation on DRAM is not the switching speed of the bus, but the time that it takes to open a row and perform a column operation on that row. Opening a row requires precharging the sense lines to the termination voltage (Vtt) which is exactly one half of the supply voltage (Vss), and then connecting one sense line from each comparator to the corresponding memory cell. If the cell is charged low, the voltage on the connected sense line will drop by a small amount. If the cell is charged high, the voltage on the connected sense line will rise by a small amount. The amount by which the line charges or discharges is proportional to the difference between Vtt and Vss. Mathematically this looks like a decaying exponential and once it has reached a certain level the sense lines can be connected to an amplifier to make a determination as to whether the cell is high or low and latch it into the DRAM's static logic for memory operations. That level is more or less fixed, and will be reached quicker as the magnitude of the distance between Vtt and Vss/GND increases. Ergo, a higher supply voltage yields faster DRAM sensing.

 

[RAMTEK]

Good explanation. Doe the lower voltage also result in lower heat dissipation as well? When choosing between two like machines, one with DDR3L and one with DDR3, what would be the choice? Is the choice slower speed with less heat, or faster speed but more heat? Is that the crux of the decision?

 

[Pinhedd]

Good explanation. Doe the lower voltage also result in lower heat dissipation as well? When choosing between two like machines, one with DDR3L and one with DDR3, what would be the choice? Is the choice slower speed with less heat, or faster speed but more heat? Is that the crux of the decision?

That's correct. DDR3L requires less energy to operate, and thus dissipates less heat but at the cost of some performance. Keep in mind though that modern DDR3L modules will perform better than older DDR3 modules simply due to improvements in design.

DDR3L modules are by design backwards compatible with DDR3 which means that they can be inserted into a motherboard that does not support DDR3L profiles without issue. I know for a fact that Hynix uses the exact same chips for both, and simply picks ones that have desirable performance characteristics for DDR3L. It would be possible to configure the complementary DDR3 modules to run at DDR3L specifications, but operation would not be guaranteed in the same way as configuring DDR3L to run at DDR3 specifications.

 

[pkincy]

Is DD3R memory that is 1.35v the same as DD3RL? It seems there is a plethora of inexpensive DD3R memory with 1.35 v. But to find memory called DD3RL is much harder and more expensive.

 

[Pinhedd]

Is DD3R memory that is 1.35v the same as DD3RL? It seems there is a plethora of inexpensive DD3R memory with 1.35 v. But to find memory called DD3RL is much harder and more expensive.

Yes, that's exactly what it is

 

[rolfcm106]

This was a very helpful thread to read through. Learned a lot, thanks.