T520 maximum memory: 16 GB, not 8

[hairo]

The official specifications for the Lenovo T520 state that the maximum supported memory is 8 GB (2 x 4 GB). Luckily, this is not true. 16 GB (2 x 8 GB) work just fine. I am running this myself. You can find more details here:

http://helgeklein.com/blog/2012/12/leno ... but-16-gb/

[wolfman]

Welcome to the forum!

Yep, agree, I have 16gb of RAM in my T420 since it was a couple weeks old. I actually sold my T410 and bought the T420 specifically because I wanted to use 16gb of RAM.

Hopefully you were able to return or find another use for the other machine, that's a bummer.

[jayton4]

I have yet to find a single Sandy Bridge or Ivy Bridge machine of any brand or model that did not work with 8GB sticks of 1600Mhz Kingston Valueram.

[mujahid7ia]

That's pretty cool. I wish my T510 (i5-520M Arrandale) could go higher than 8 GB.

[underclocker]

I've had 16GB in my T520 for a while, too. Corsair Value Select works just fine.

[wolfman]

I've had 16GB in my T520 for a while, too. Corsair Value Select works just fine.

Agreed, this is the same RAM I'm running in my T420.

[T400plus]

After reading the replies here...I am tempted to ask...I have a old old T400.
How much maximum memory can i tempt it with?.currently i have 4GB+2GB=6GB.
type 2765-T6U---out of warranty...

[wolfman]

8gb of RAM (4gb x 2) is your max on the T400. So you can take out your 2gb stick and replace it with a 4gb stick.

[Core Share]

Thus, would 2 X 8GB be suitable for an X220 as well?

[wolfman]

Thus, would 2 X 8GB be suitable for an X220 as well?

Yes it will.

[Core Share]

Hot diggety dog!

Thank you for the confirmation.

16 GB of deep, deep space coming my way; after my T40 (still my primary machine) and my x60s, when the X220 is also kitted out with an SSD - my mind will be officially blown.

[BobA]

I also upgraded my T520 from 8G to 16G and added a 128G mSATA drive. I did some benchmark testing and discovered I got more bang for the buck by upgrading to the mSATA. The memory upgrade did increase performance, but not as significantly as booting from the mSATA. A delightful system ..

[andrx]

For the people who might be searching for information about whether you can upgrade a T520 to 32GiB of memory:

Some T520 models come with CPUs that officially only support 16GiB of memory,
For example the i5-2520M:
http://ark.intel.com/products/52229/Int ... o-3_20-GHz

However some other models come with i7 CPUs that officially support 32GiB memory,
For example the i7-2670QM
http://ark.intel.com/products/53469/Int ... o-3_10-GHz

The T520 only has two SODIMM slots, and recently 16GiB SODIMM modules have become available,
and they aren't cheap, so I didn't just buy them to try them out, instead I went on looking up whether the
cpu will support these, and I believe the answer is NO.

The explanation is this:
An SODIMM can support per module:
- a maximum of 64 data bits
- a maximum of 2 ranks
- a maximum of 8 banks
- a maximum of 16 row addresses
- a number of column addresses

Column address bits 0..9 are transmitted on A0..A9.
The A10 line is used to transmit the Auto Precharge signal.
According to the JEDEC spec, if the memory has a C10 column, then it will have to be transmitted on the A11 address line.

So there is a hole in the mapping from column address bits to actual physical address lines, and it is conceivable,
that some memory controllers will not support driving the A11 line (and above) when specifying column addresses.

And that is exactly what's going on, the Intel 2nd generation i7 CPU memory controller is not able to drive the A11 signal correctly.
That means that this controller is not able to talk to SO-DIMM modules that are larger then 64 * 2 * 8 * 2^16 * 2^10 / 8 bytes =
8589934592 bytes = 8.0 GigaBytes

That being said, the W520 model should in theory be able to support 32GiB of memory with the right processor, and with 4x8GiB sticks,
because it has 4 SODIMM slots.

I have also found some hints on the internat that the 5th and 6th generation i7/i5 cpus support >=16GiB SODIMM modules,
but that this is unofficial, and intel doesn't support this usecase.

[RealBlackStuff]

That being said, the W520 model should in theory be able to support 32GiB of memory with the right processor, and with 4x8GiB sticks,
because it has 4 SODIMM slots.

Not only in theory, but also in real life, W520 with quad-CPU and 4 RAM-slots supports 4x8GB=32GB.
Mind you, not all W520 motherboards have 4 RAM-slots! The others have 2 slots and only support 2x8GB=16GB.

[MikalE]

I'm very happy with the performance of my T520 using the i7 2620 and 16 GB of RAM. I don't really have any software or applications that would benefit from the use of 32 GB, though I would surely want it if it were possible just for bragging rights.

[lembang]

@MikalE

I don't see a point of having 32GB RAM, if you not rendering 3D model or running a VM.
16GB is already more than enough.