X201 memory upgrade

[qpad]

I want to upgrade the memory in my Thinkpad X201 to 8GB.

The Lenovo support site here recommends PC3-8500 memory, running at 1066 MHz. But the advisor tool at http://www.crucial.com wants me to get PC3-12800, at 1600 MHz.

Can I assume that is because PC3-8500 is obsolete, and those newer chips will work just as well? Some memory discussions around the web seem to assume that higher clocked memory has a higher latency, and others seem to want memory speed to be in some favorable relation to the speed of the FSB...

[ZaZ]

You can buy the faster memory, but there will be little if any practical difference between the two. I'd buy whatever is less expensive.

[qpad]

From what I've learned, it seems whatever modules I buy, they will not run faster than 1066 MHz.

But it is harder to get to the bottom of the issue of latency, and what memory will actually work in the X201. For example, I've found PC3-15000-memory (also a 204 pin DDR3 SO-DIMM) that is cheaper and has a lower latency than the PC3-12800 recommended by Crucial. But will it work in the X201?

Plus, If I buy memory at some clock frequency faster than 1066 MHz, so that the system will have to clock it down, will the latency / cl values also change? Or the performance change in some other way?

[Dekks]

The faster memory will just go as fast as the chipset will work at. Got a surprise on my 2nd hand x201i which runs 8GB crucial recommended RAM at 1600Mhz, which is supposedly faster than book speed.

[Elwyn]

I've got a x201 here with 4GB Ram of 2x2gb 1Rx8 PC3 8500S, and checked online with Crucial then ordered 2x4GB DDR 1600 SODIMM. However, that failed to work.

I tried one of the 4GB sticks in the machine in either slot, as well as with a 2 in there and a 4. It recognised it in the bios but wouldn't boot windows

The BIOS reports: BIOS: LENOVO 6QET62WW (1.32 ) 12/17/2010

[RealBlackStuff]

Latest BIOS (bootable CD) 1.40/1.15: http://download.lenovo.com/ibmdl/pub/pc ... uj19us.iso

That RAM speed is too high, you need PC3-8500 (DDR3-1066) or PC3-10600 (DDR3-1333) SODIMMs, max. 2x4GB

[Elwyn]

Indeed. However, at the time, the suppliers were telling me that all the systems would cope and down speed the ram to match. But clearly they were all incorrect...

Does the X220 come with the slower ram by standard or the faster stuff?

[friedrich-eugen]

RealBlackStuff,

The maximum memory is 4GB or 8GB per slot for an x201T i7-machine?

Thanks in advance

[RealBlackStuff]

X201/X201s/X201T only support 8GB RAM total (i.e. 2x4GB).