Is R1 and R2 RAM compatible with each other?


I’m using the Toshiba Satellite Pro R50-B-112 Laptop and I wated to upgrade the RAM from 4GB to 8GB.
Since only one slot is occupied, I’ve bought another RAM module. So I’ve bought (almost) the same RAM module (4GB DDR3 12800 1600MHz). The only difference is, that the new module is R2 while the old module is R1.

The Laptop doesn’t work with the new module, if I take the old one out and also doesn’t see the new module, if I leave both in the slots. Is it possible, that R1 and R2 are incompatible? Or is it likely, that the module could be broken on arrival? (never had this problem so far)

I also did a BIOS update and it didn’t help.

Is the R1 and R2 what it says at the end of the spec? Like PC3-12800-9-11-11-R1?

R1 / R2 / R3 stands for the rank
Here’s the wikipedia article to it.

It’s basically the number of RAM lanes on your RAM module
(just as an example)
Here’s a R1 module
Here’s a R2 module

If it doesn’t work with neither the old and new sticks at the same time nor with just the new stick by itself it either means the RAM is dead or your laptop is not compatible with it.


Yeah as @w.meri says, it is probably not incompatibility. It is possible though, but not likely. Especially not likely if it won’t recognise it at all. I have had issues where a module would mess up graphics on some laptops, but not others. It would still be fine 99% of the time.

Memory isn’t going to work if you mix ranks. It might work by itself.

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If you got a Lenovo T430s with 8GB of RAM, it was sold, by Lenovo themselves, with an R1 and an R2 rank kit of 2x4GB. Mine even had two different manufacturers and one was 1.35v the other 1.5v. They almost couldn’t have been more different.

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If you use both types at the same time, the device will not work.

hello welcome to the forum unfortunately you’ve responded to a really old post, please consider looking at dates before replying to old posts and necro’ing a thread