Upgrading Memory - Which Should I Choose?

Long story short, I have a Lenovo x201t (Model 2985C5U) with 4GB of memory, and I thought I'd go ahead and max it out to 8GB.

The following is via Crucial's System Scanner
# Maximum Memory Capacity: 8192MB
# Currently Installed Memory: 4GB
# Available Memory Slots: 0
# Total Memory Slots: 2
# Dual Channel Support: No
# CPU Manufacturer: GenuineIntel
# CPU Family: Intel(R) Core(TM) i7 CPU L 640 @ 2.13GHz Intel(R) Core(TM) i7 CPU L 640 @ 2.13GHz
# CPU Speed: 2134 MHz

Lenovo's PSREF also lists the laptop as being able to support up to 8GB of ram.

Also according to Crucial:
Each memory slot can hold DDR3 PC3-8500, DDR3 PC3-10600 with a maximum of 4GB per slot.*

While I'm not necessarily tied to Crucial (though I might end up getting Crucial's memory anyway) it looks like it comes down to 2 basic varieties:

Option 1
Part #: CT1573292 • DDR3 PC3-10600 • CL=9 • Unbuffered • NON-ECC • DDR3-1333 • 1.5V • 512Meg x 64 • •

Option 2
Part #: CT1573300 • DDR3 PC3-8500 • CL=7 • Unbuffered • NON-ECC • DDR3-1066 • 1.5V • 512Meg x 64 • •

Basically, my question revolves around which is better:
A faster speed (PC3-10600 > PC3-8500)
Or the lower CL (PC3-8500 > PC3-10600)

Note the price on both is identical.

For reference:
Wikipedia's Module Comparison

CL — CAS (column address strobe) latency, which is the number of clock cycles it takes before data starts to flow after a command is received. Lower CL is faster. Modules with different CL can be mixed on a system, but the system will only run at the highest (slowest) CL.

Thoughts and comments? (And yes, I am aware I need a 64 bit OS)

 

It really doesn't matter, your dual core i7 doesn't support 1333 RAM.

However the newest SB processors support 1333/1600 modules so I would just stick with 1333 RAM, there shouldn't be a huge price difference. The faster RAM only makes a difference in synthetic benchmarks, real world use you will not see a difference.

 

It doesn't? Crucial's scanner had it come up as an option, and Kingston also listed it as compatible... Kingston

 

Arrandale i7 are all dual core and only natively support 1066 DDR3 RAM. 1333 will work but will automatically downclock to the 1066.

 

True story!

Buy the 1333 if the price is the same - this way you don't loose or win anything performance-wise, but ensure a better resell value and chances after some time...! That's what I did too - bought 1333 to upgrade to 6GB. But if there is a price difference- buy whichever is cheaper - it makes technically no difference to you - the faster will be downclocked.

 

Tsunami_Kid and Gracy are both right. Buy whatever is cheaper. If both are the same price, get the one with the higher frequency rating. It will downclock and tighten its timings to be just like the lower frequency one anyway.

 

Trottel, not once have you spelled my name correctly.

As for RAM recommended; Crucial, Corsair, GSkill, Kingston are reputable brand names.

 

The many discussions about what brand RAM one should get lead to the conclusion that "RAM is RAM" and it is one of the least things in this world where brand really has almost no meaning, but at the same time avoid mega-cheap and unknown RAM to save yourself some troubles!

I say - buy the cheapest RAM from the known brands! There is absolutely no reason why you should buy an expensive brand, unless you plan overclocking it.

As Tsunade_Hime (I think I spelled it right but what does this even mean!?) mentioned above: Crucial, Corsair, GSkill, Kingston, OCZ, Hynix, Samsung...

 

I have to pretty much agree with the sentiment "RAM is RAM" take this link below for example from newegg, it's labeled and sold as Kingston but it's clearly manufactured by Elpida (the same oem RAM that came in my ASUS btw)

Newegg.com - Computer Parts, PC Components, Laptop Computers, LED LCD TV, Digital Cameras and more!

 

Correct RAM is RAM is RAM but the companies I listed are very good about their warranty services, just like hard drives, I only buy from certain manufacturers because their warranty and support are much better than certain other companies.