Sorry, Another stupid memory question...5300 vs 6400

[xultar]

Based on the Lenovo web site, 200-pin SODIMM, DDR2 PC2-5300  is supposed to be the correct memory for my machine.
But,
What I'd like to know is if I can use 200-pin SODIMM, DDR2 PC2-6400 memory module and benefit from faster memory?

And, is the Lenovo saying that 5300 correct because that is all they offer or is it really not good for me to use 6400?

Again thanks.

I'm so lovin my T61 widescreen!

[nightwings]

As far as I know, you can use 6400 RAM (DDRII 800), but the computer will use it as 5300 (DDRII 667).
The frequency will be reduced to 667, and the computer does not run faster. Unless you do overclocking.

[icantux · Accepted solution]

Correct!

The memory bus speed on T6x and X6x systems is only 667MHz (PC2-5300), so you gain nothing by inserting faster-rated RAM (800MHz PC2-6400) in those systems even though the system will accept that type of RAM.... The 6400 RAM will only work at a reduced 667MHz speed.

[xultar]

Thanks so much!!!

[sambaverde]

thats strange

im running a t61p with 2GB(original) of DDR2-5300 RAM so is should be 66MHz FSB or?

systemmanager and CPU-Z tool show a rated FSB of 800MHz!!

my CPU is a T7700 

the T61 maintainance manual from IBM/Lenovo shows that DDR2-5300 should be used

so whats going on? 

  is LENOVO overclocking ?

  are the tools displaying the FSB wrong

i'd like  to ugrade to 3 or 4GB so what do i buy? DDR2-5300(667) oder DDR2-6400(800)

regards

Martin

[wjli2]

The FSB maybe 800 mhz, but the RAM speed is restricted to 667 mhz max. 

[sambaverde]

so it would be better(and in the end faster) to get DDR2-6400 although the manual says DDR2-5300?

regards

[wjli2]

you won't be able to get the speed boost and it would as much as 1.5 times more for the same amount of ram, also all the new Thinkpads use DDR 3, so it is a redundant investment. 

In my opinion it is not worth it, but in the end it is up to you.  

[sambaverde]

ok, so i stay with ddr2-5300

thanks!

 Martin

[StickyTape]

Note that those of you with X61 laptops from April 2008 onwards are likely to be using Penryn processors which do run at 800 MHz FSB. Therefore you can install the PC2-6400 modules and take advantage of the minor speed increase. I am running two PC2-6400 2GB modules on this laptop, having taken out the old 1GB PC2-5300 ones.

In any case the bus speed will adjust the RAM speed to 667 if you buy the new memory for the older Santa Rosa platform.

Apparently the X61 will support up to two 4GB modules, though of course, you will never use this memory and it will cost you in the range of €350

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X61 T8300 2.3GHz 4GB PC2-6400 Vista SP1 Business x64

Message Edited by StickyTape on 01-09-2009 12:44 PM