RAM configurations in Sager NP8651/Clevo P650SE

I have 2x8GB DDR3 1600MHz CL9 and 2x4GB DDR3 1600MHz CL11. I'd like to have 24GB in dual channel. How should the RAM be installed? And before you say it, yes, I could just do 16GB in dual channel running at CL9, but I have reason to want 24GB in dual channel, even if it is at CL11.

I know that desktop systems have color-coded and numbered RAM slots, and the RAM needs to be installed in matched symmetry to get dual channel ( reference). Obviously there's no such color coding on the NP8651/P650SE, but the slots are still numbered.

I've gotten conflicting information about whether getting 24GB in dual channel is even possible, and if it is, in what configuration the RAM should be installed.

Should the 2x8GB sticks go in slots 1 and 2, and the 2x4GB in slots 3 and 4? Or should the 2x8GB go in 1 and 3 and the 2x4GB go in 2 and 4? Or something else entirely? Or does it not matter, and I'll get 24GB dual channel either way? Or does it not matter, and I'll be stuck with 24GB single channel either way?

And just in case I do get stuck with single channel, and thus want to go back to 16GB dual channel CL9, do the 2x8GB sticks go in slots 1 and 2? Or does it not matter?

Thanks in advance.

 

I have 2 and 2 different pairs of SO DIMMs installed as slot #1 + slot #3 and slot #2 + slot #4 - but physically slot #1 & #3 are together (easy access from the bottom side) and so are slot #2 & #4 (under keyboard)

 

afaik ull be fine no matter how u install the sticks. but beware that theyll take on the speed of the slowest installed stick, thus theyre all gonna run in dual channel at 1600mhz with cl11 and not cl9

 

Yeah, that I know and am OK with. I'd rather deal with CL11 than with swapping to disk.

 

Too keep it all in dual channel the matched pairs need to be next to each other.

It's physically laid out so channel a1 and b1 are next to each other for dual channel as are a2 and b2 even though electrically they are not the same channel. It makes it easier to know.

If you install it so the 4gb and 8gb are next to each other you will get 16gb of ram in dual channel and 8gb in single channel.

 

So, based on the pics posted by Eurocom, the slots marked RAM1 and RAM2 are under the keyboard, and RAM3 and RAM4 are on the bottom. In this case, I assume RAM1 would be a1, RAM2 would be b1, RAM3 would be a2, and RAM4 would be b2?

I guess the easiest solution here would be to put both 8GB under the keyboard, since I'll likely be leaving them there and not needing to touch them, and put both 4GB on the bottom, where they can be accessed more easily when the time comes to upgrade, and this will put all 24GB into dual channel, correct?

I understand that putting 4GB in a1 and 4GB in a2, and 8GB in b1 and 8GB in b2 would lead to 16GB in dual channel and 8GB in single channel... but just for the sake of curiosity, what would happen if I put 8GB in a1 and 4GB in a2, plus 4GB in b1 and 8GB in b2? Each channel would have 4GB plus 8GB, but would I get dual channel?

 

haha, i can already see you trying all possible ram install permutations once u get ur rig

 

Already on it.

 

Oh, I will, I'm sure

I'll probably still do it, just to see if I get the same results

 

You got the slots right.

Think of a1 and b1 as a pairing. Like raid 0 you stripe data across. You keep striping until one module runs out. The extra capacity in the other is now single channel.

The only way to max your dual channel is to pair the 4gb with 4gb and 8gb with 8gb. You can pair them either way so 4gb in a1 and b1 (under cover) or a2 and b2 (under keyboard) and vice versa with 8gb.

 

I just validated what Meaker said in the P650SE:

Say 1a and 1b are under the keyboard and 2a and 2b under the bottom panel. Anything in an "a" slot and "b" slot together resulted in dual channel.

So a+a = single channel, b+b = single channel, a+b = dual channel.

a+a+b = dual channel memory of smallest of a+b
a+a+b+b = dual channel memory of smallest of a+b + a+b

i.e.;
- 4GB in 1a, 8GB in 1b, 8GB in 2a would result in only GB dual channel (4GB 1a + 4GB of the 8GB 1b) + 4GB single channel
- 4GB in 1a, 8GB in 1b, 8GB in 2a, 4GB in 2b would result in 16GB dual channel (4GB 1a + 4GB 1b) + (4GB 2a + 4GB 2b)
- 8GB in 1a, 8GB in 1b, 4GB in 2a, 4GB in 2b would result in all 24GB in dual channel

whew... I think I got that right.

Just easiest to match pairs in each pair slots next to each other!!!

 

example



crucial so-dimms a physically together as a pair and kingston so-dimms are physically together as a pair ...

 

Yes they put them physically together since it makes it a lot more convenient, desktops keep them all together since they can and put them in electrical order to help performance.

 

Sorry to revive this thread but I need help sourcing out the right Ram for my p650se
It came with a 8gb DDR3 1600 PC3-12800 SO-DIMM.
Do i need to get another memory stick to match exactly those specs? Or can i get 2x4gb sticks?
The only one i found equivalent so far is crucial and kingstons that match the lapop memory.

 

Goto newegg and check out g. Skill. Put the slots in your cart and/or wish list and save it. New egg will send you a coupon sooner or later for 10% off ram. You can do this for a lot of computer parts and get various coupons this way. I spent $264 shipped for 4x8gb 1600 9-9-9-28 g. Skill ram. Or whcbever brand you prefer. Crucial is also good.
Newegg is usually cheapest on ram it overall.

 

Make sure it is 1.35V ram. Your machine will currently look like:

Slot 1) 8GB DDR3L 1600mhz CL11
Slot 2) Empty
Slot 3) Empty
Slot 4) Empty

To be most efficient you would pair up the 8GB stick with another identical one and still leave room for another 16GB should you need it in future.