Hi.. My current laptop use Samsung DDR3 2GB (533MHz).

And I just bought a new one => Samsung DDR3 1600MHz PC3-12800 4GB

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Need advice. For best performance... should I replace the old ram with the new one, or should I use both of them on the laptop (Toshiba Sattelite L645)

Thanks.

You actually tried install both at same time already?

Cause 1066mhz DDR3 ram is near extinct already, and laptop back then not necessarily can support 1600mhz ram.

This post has been edited by Human10: Apr 14 2014, 10:56 PM

p/s: Just googled your laptop, the processor seems to be gen1 i-series.

And from here, I think the most your processor can support is just 1066mhz.
http://ark.intel.com/products/50178/Intel-...-Cache-2_53-GHz

This post has been edited by Human10: Apr 15 2014, 12:27 AM

I believe I'm opening this topic on a wrong section. Anyway thank you so much for your answer..

Since the most it can support is 1066mhz, does that mean I can't use the 1600mhz ram?

Or I can use it.. but the speed will be reduced to 1066 mhz??

Have you tried installing the 1600mhz ram?

Cause my laptop of similar gen to yours, I can't boot up with 1600mhz RAM.

But for 1333mhz ram, it boot up fine and automatically downclock to 1066mhz by itself.

I just installed the ram.. it boot fine

Check the speed, it run at 533mhz in cpuz right?

Yup.. that's right. But I think that's fine as long I can boot

Yeah, that's the most important point.