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Can I add 2x4gb to my current 2x2gb and use them as 12gb?

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September 24, 2012 6:41:02 PM

I have 64bit OS and MB that supports up to 32gb ram (4 slots).

Ram would be at the same speed 1600mhz and CL9, from kingston.
September 24, 2012 7:38:20 PM

mrbeanladen said:
Memory would be at the same speed 1600MHz and CL9, from Kingston.


Are the previous/current Memory exactly the same? It's very important, since the Memory planks should be absolutely the same model, even if they have different capacity.

They should be the same model, same frequency, same timings and same voltage. As long as all of these requirements are matched, your Memory would work perfectly even if planks have different capacity (but you won't be able to use Dual Channeling or Triple Channeling benefits, remember that).

Note that you CAN use different Memory plank models with different parameters and even from different manufacturers, but it is very strongly not recommended to do such combos.
September 24, 2012 7:41:05 PM

master_chen said:
Previous Memory exactly the same? It's very important, the Memory planks should be absolutely the same model, even if they have different capacity.

They should be the same model, same frequency, same timings and same voltage. As long as all of these requirements are matched, your Memory would work perfectly even if planks have different capacity (but you won't be able to use Dual Channeling or Triple Channeling benefits, remember that).

Yeah, It's kingston hyperx blue something, cl9 1600mhz, 9-9-9-27 to be precise. The new ones I'll get would be 8gb, 2x4gb (I have now in my PC 2x2gb) and 1600mhz, cl9 and I think even the same heatsink but obviously that doesnt matter.

So, could I use them as 12gb? If not, I'll give them to a friend of mine who needs a new PC.
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September 24, 2012 7:48:38 PM

mrbeanladen said:
So, could I use them as 12GB?


I can't say that I'm 100% sure, because before I make a 100% assured comment I need to look at them (link to newegg, or to any other hardware online shop, would be very helpful).
But I'd say that it's about 95%/5% in the favor of it being able to work just fine.
a b } Memory
September 24, 2012 7:50:38 PM

mrbeanladen said:
Yeah, It's kingston hyperx blue something, cl9 1600mhz, 9-9-9-27 to be precise. The new ones I'll get would be 8gb, 2x4gb (I have now in my PC 2x2gb) and 1600mhz, cl9 and I think even the same heatsink but obviously that doesnt matter.

So, could I use them as 12gb? If not, I'll give them to a friend of mine who needs a new PC.

You can use them as 12 GB and maintain full dual channel mode as long as you install each matched pair in the correct DIMM sockets on the motherboard.
September 24, 2012 7:54:34 PM

ko888 said:
You can use them as 12 GB and maintain full dual channel mode as long as you install each matched pair in the correct DIMM sockets on the motherboard.

yea i see the slots are colored differently 2 are blue 2 are white.
So they'd run in "dual channel" individually? dual channel 4gb + dual channel 8gb?
September 24, 2012 7:55:33 PM

^^ exactly. There is a small chance that all 4 sticks might not play along nicely. This is why some manufacturers sell kits with 4 sticks in them because this a guaranteed compatibility. In your case compatibility is not guaranteed but it has a real good chance of working. Consult your motherboard manual and install the sticks so that the 4GB sticks are in dual channel and the 2GB sticks are in dual channel. In most motherboards it would be like this [4GB][2GB][4GB][2GB] but like I said check your manual.
September 24, 2012 7:55:41 PM

ko888 said:
You can use them as 12 GB and maintain full dual channel mode as long as you install each matched pair in the correct DIMM sockets on the motherboard.

His slots would be completely full. Correct me if I'm wrong, but Dual Channel only works when there are only two planks inserted in the same-colored slots, other two being empty, or it won't work (thus, Triple Channel only works when only three planks are inserted in a 6-plank motherboard, in all same-colored slots only).
a b } Memory
September 24, 2012 7:57:11 PM

mrbeanladen said:
yea i see the slots are colored differently 2 are blue 2 are white.
So they'd run in "dual channel" individually? dual channel 4gb + dual channel 8gb?

Yes.
September 24, 2012 8:03:59 PM

stickg1 said:
[4GB][2GB][4GB][2GB]


I think that might work if the planks are of different models, but not when they are completely same.

Well, since they are of different capacity, I guess that they're of different modeling (even if it doesn't really shows much) nonetheless.
September 24, 2012 8:56:05 PM

master_chen said:
I think that might work if the planks are of different models, but not when they are completely same.

Well, since they are of different capacity, I guess that they're of different modeling (even if it doesn't really shows much) nonetheless.


A 4GB stick is a different model than a 2GB stick. That's why you keep the same capacity on the same channel for dual channel mode.
a b } Memory
September 24, 2012 9:10:34 PM

Yes, I believe you can put different capacities in as long as they are together inside of the memory banks (DIMM1: 2gb DIMM2: 4gb DIMM3: 2gb DIMM4 4gb). It is not guaranteed to work though!
September 24, 2012 9:12:05 PM

chugot9218 said:
Yes, I believe you can put different capacities in as long as they are together inside of the memory banks (DIMM1: 2gb DIMM2: 4gb DIMM3: 2gb DIMM4 4gb). It is not guaranteed to work though!

Hmm... so... you think 12gb vs 8gb makes any difference? Is it worth the hassle or should I just give my friend the old pair of ram?
a b } Memory
September 24, 2012 9:14:49 PM

I don't think it would damage your MOBO to try, I remember specifically looking into the DDR3 architecture and it stated in the article that you can use RAM of different capacity. I believe timings had to be the same though, I will try and find my source and post it (it may be wikipedia but I find a little further research usually confirms most articles there).
a b } Memory
September 24, 2012 9:17:10 PM

Here is the relevant section from wikipedia:

Operation
Dual-channel architecture requires a dual-channel-capable motherboard and two or more DDR, DDR2 SDRAM, or DDR3 SDRAM memory modules. The memory modules are installed into matching banks, which are usually color coded on the motherboard. These separate channels allow the memory controller access to each memory module, increasing throughput bandwidth. It is not required that identical modules be used (if motherboard supports it), but this is often recommended for best dual-channel operation. It is possible to use a single-sided module of 512 MB[4] and a double-sided module of 512 MB in dual-channel configuration, but how fast and stable it is depends on the memory controller.
If the motherboard has two pairs of differently colored DIMM sockets (the colors indicate which bank they belong to, bank 0 or bank 1), then one can place a matched pair of memory modules in bank 0, but a different-capacity pair of modules in bank 1, as long as they are of the same speed. Using this scheme, a pair of 1 GB memory modules in bank 0 and a pair of matched 512 MB modules in bank 1 would be acceptable for dual-channel operation.[5]
Modules rated at different speeds can be run in dual-channel mode, although the motherboard will then run all memory modules at the speed of the slowest module. Some motherboards, however, have compatibility issues with certain brands or models of memory when attempting to use them in dual-channel mode. For this reason, it is generally advised to use identical pairs of memory modules, which is why most memory manufacturers now sell "kits" of matched-pair DIMMs. Several motherboard manufacturers only support configurations where a "matched pair" of modules are used. A matching pair needs to match in:
Capacity (e.g. 1024 MB). Certain Intel chipsets support different capacity chips in what they call Flex Mode: the capacity that can be matched is run in dual-channel, while the remainder runs in single-channel.
Speed (e.g. PC5300). If speed is not the same, the lower speed of the two modules will be used. Likewise, the higher latency of the two modules will be used.
Number of chips and sides (e.g. two sides with four chips on each side).
Matching size of rows and columns.
Dual-channel architecture is a technology implemented on motherboards by the motherboard manufacturer and does not apply to memory modules. Theoretically any matched pair of memory modules may be used in either single- or dual-channel operation, provided the motherboard supports this architecture.

And here is the full page:

http://en.wikipedia.org/wiki/Dual-channel_architecture
a b } Memory
September 24, 2012 9:18:23 PM

mrbeanladen said:
Hmm... so... you think 12gb vs 8gb makes any difference? Is it worth the hassle or should I just give my friend the old pair of ram?

Install all four DIMMs and see if it's stable. If it's stable then keep them. If it's unstable give away the 2x2GB DIMMs.
September 24, 2012 9:23:25 PM

mrbeanladen said:
Hmm... so... you think 12gb vs 8gb makes any difference? Is it worth the hassle or should I just give my friend the old pair of ram?


8GB is plenty for a gaming machine. Unless you do other tasks on your computer that require lots of RAM I would probably just give the 2x2GB to a friend in need. Check to see if it's stable though. You could always use that extra 4GB of RAM as a RAMdisk for a cache to speed your computer up a little.
September 24, 2012 10:10:07 PM

stickg1 said:
A 4GB stick is a different model than a 2GB stick.


Actually...there are planks out there that can differ in capacity, but not the model or other parameters. I tried some of those a couple of times, in the past (I think they were DDR2).

To OP on "12GB necessity"...I'll just quote myself from one of the previous similar threads:
Quote:
Usually, getting more than 24GB would be just like applying a safety pillow while wearing a seat belt, nothing less or more than just that.
You'll almost never find a situation where you will actually need more than 8GB.


This, pretty much, stays true to "12~16GB" too.
!