Can I run my Alienware 18 with 2 sticks of 4GB under the keyboard and 1 Stick of 8GB under the back?

Can I run my Alienware 18 with 2 sticks of 4GB under the keyboard and 1 Stick of 8GB under the back?

 

You can, and will be the best way to kill your performance this way since you won't run in Dual Channel DDR mode. Only put RAM in matching pairs across the entire motherboard.

 

So I have to take out the two 4 sticks under the keyboard or put two more in under the bottom? I purchased two 8Gig sticks not realizing it had the two 4gig under the keyboard. I hate going under there.

 

Buy another 2 of the 8 gigs you purchaed, the same exact ones. You need to have the same speed, size, CAS latency to achieve Dual Channel mode.

I would take less RAM in Dual Channel over more RAM in Single Channel any time of the day

Also note that the matching pairs need to be:

Same RAM matching pair in SLOT 1 / 3

Same RAM matching pair in Slot 2 / 4

that is the info I got from DELL

the best way to remove all doubts is to put the same RAM across all slots and be done with it then sell your older RAM or put it in another computer

 

In notebooks the pairs are put together to give dual channel, 4 + 4 + 8 will give you 8GB in dual channel and 8GB in single channel no matter the arrangement in the slots Either the 4GB sticks will be interleaved together and the 8GB will be by itself or a 4GB stick will be interleaved with half the 8GB stick leaving the remain 4GB single channel and the 4GB stick in single channel giving the same result.

Modern memory controllers are pretty smart

 

We recommend to match all RAM sticks for a better performance. This setup will work, however the upgrade won't be that noticeable because as stated above, it'll run on Single Channel.

 

Well I purchased two sticks of 4 gigs each From Dell and put them in my 18 and nothing but black screen and beeps on boot up. Help!

 

Is it possible that I needed DR3L and purchased DDR3?

 

You absolutely need DDR3L for the 18. It won't run with the DDR3 1.5V... I've tried and it won't boot.

 

It depends on the ram, some 1.5V will be able to run at 1.35V but just like overclocking you enter the silicon lottery. The faster the sticks the less likely you are to get away with it.

 

Even if 1.5V sticks do run, they will burn the motherboard with time. Haswell = 1.35V / PERIOD

 

That's gotta be it!

 

No the sticks will be fed 1.35V even if they are rated at 1.5v, a bit like undervolting a CPU. The motherboard governs that and not the ram.

 

oh pardon me then. The reason I said that is that on the ASUS ROG Forums, when the G750JX was first released, there was a sticky about not installing 1.5V memory because even if it works, it might damage the motherboard on the long run. my bad

here's the thread:

http://rog.asus.com/forum/showthrea...ry-required-in-G751-G771-G551s-(same-as-G750)

 

Lol, well they are wrong, but it's not the first time i've seen that. Mobile haswell provides 1.35v at all times to the memory, intel have specified this.

 

My Alienware 18 runs a 2 x 8, 2 x 4 (24gb) of the same crucial RAM. Is this in dual channel mode despite the different totals?

 

So long as the sticks are each paired with the same size then all of it is dual channel, if they are paired oddly (4 with 8) then you have half of it in dual channel and the other half single.