Depending on where you are, good morning good afternoon, good evening !
Slowly but surely upgrading my recording kit and now I need to upgrade my memory, but as usual confused by all the numbers and choices out there !

Win 7 64bit
M/board Asus P7P55D-E

Currently with 4GB- 2 x 2GB of Kingston Hyper-X Blu dual-DDR3 1600Mhz XMP.
want to go to 8GB

Board has 4 slots so am I best to get 2 more of the above or should I replace it with 2 x 4GB of the above.
Or can I keep the current 4GB and put in 8GB more and have 12GB, or doesnt it work like that ?
or do you have any more suitable suggestions.

I also do a fair bit of video editing so definitely need to up my memory but as with all this stuff I find all the numbers confusing.

all advice appreciated
Many thanks

You can add another 2x4 and run 12GB, that will be fine. Just be aware that if you buy slower than 1600mhz RAM then all 4 sticks will run at the speed of the slowest RAM. Or that's the way it used to be!

Saying that, RAM is so cheap you could even put in 4x4 and have 16GB!

Thanks for the reply.
i'm confused already, the spec of what ram I currently have was taken from the original PC purchase leaflet, I have just d/loaded and run Speccy and get this below (I didnt print slot 2 as it seems to be the same as slot 1)

This is what I'm looking to get

http://www.amazon.co.uk/dp/B0057Q4ADU/ref=asc_df_B0057Q4ADU8 477193?smid=A3P5ROKL5A1OLE&tag=googlecouk06-21&linkCode=asn& creative=22206&creativeASIN=B0057Q4ADU

Is it going to be ok voltage wise etc with what speccy says I already have


RAM
Memory slots
Total memory slots 4
Used memory slots 2
Free memory slots 2
Memory
Type DDR3
Size 4096 MBytes
Channels # Single
DRAM Frequency 668.5 MHz
CAS# Latency (CL) 9 clocks
RAS# to CAS# Delay (tRCD) 9 clocks
RAS# Precharge (tRP) 9 clocks
Cycle Time (tRAS) 24 clocks
Command Rate (CR) 1T
Physical Memory
Memory Usage 44 %
Total Physical 2.00 GB
Available Physical 1.10 GB
Total Virtual 4.00 GB
Available Virtual 2.69 GB
SPD
Number Of SPD Modules 2
Slot #1
Type DDR3
Size 2048 MBytes
Manufacturer Kingston
Max Bandwidth PC3-10700 (667 MHz)
Part Number 9905403-137.A00LF
Serial Number 3D34D9CF
Week/year 34 / 10
SPD Ext. EPP
XMP--2
Frequency
JEDEC #4
Frequency 685.7 MHz
CAS# Latency 9.0
RAS# To CAS# 10
RAS# Precharge 10
tRAS 25
tRC 34
Voltage 1.500 V
JEDEC #3
Frequency 609.5 MHz
CAS# Latency 8.0
RAS# To CAS# 8
RAS# Precharge 8
tRAS 22
tRC 30
Voltage 1.500 V
JEDEC #2
Frequency 533.3 MHz
CAS# Latency 7.0
RAS# To CAS# 7
RAS# Precharge 7
tRAS 20
tRC 27
Voltage 1.500 V
JEDEC #1
Frequency 457.1 MHz
CAS# Latency 6.0
RAS# To CAS# 6
RAS# Precharge 6
tRAS 17
tRC 23
Voltage 1.500 V
Slot #2

Thanks

http://www.asus.com/Motherboards/Intel_Socket_1156/P7P55DE/
Visit the tab "Memory/Device Support"
Download the zip file.
It contains pdf files stating what memory modules are comatible with your motherboard.

If you want a safe bet, then either get another pair the same as you have right now or get 4x4GB.

Watch out for the CL Times!

The CAS Latency is (roughly explained) a sort of "release time" similar to a compressor. The higher the CL value is, the more time a memory cell will take to "regenerate" between two read or write cycles and be available again.

So get the lowest CL times you can find. CL-9 is pretty standard and lame, CL-8 is relatively common, but try to get CL-7 modules if you can find (and afford) them.

If your mainboard has 4 RAM slots, that means it probably runs in Dual Channel mode as long as you put in pairs of RAMs.
It's best for system stability not to "mix" various sorts, so either get some more of the ones you already have, or get a new set of ones with maybe lower CL timings.

Usually it doesn't matter if you use (for example) 4x 2GB or 2x 4GB combinations, because with 4 RAMs the total amount of memory might be spread around 4 banks - but it's still only connected to the CPU over the one memory bus, so there's no actual "better" solution.

I'm just getting more confused now.

I have 4GB 2x2GB as detailed in my earlier post.

Can I install the ones I have linked to (see earlier post) 8GB 2x4GB giving me total 12GB, or replacing the current memory installed by themselves giving me 8GB.

as far as i can tell the ones I am looking to get are the same spec ie Kingston Hyper Blu XMP 1600, just higher mem capacity.

Can anybody confirm that for me please

You CAN stick any combination of RAMs in there.
You could even use 4 completely different ones, all different manufacturers, capacities, timings, etc.

That would probably switch to Single Channel mode and make the system a little slower, but it would still "work".

To have a faster Dual Channel system, all you need to do is have twos of "equal" modules in there per pair-of-module-bays.

There are two more module bays free on your board, so just get any set of modules with any capacity. Just be sure that the MHz are the same as your current modules, that'll do.

You could also put higher MHz ones in there, but they wouldn't be used at their full speed, so no gain there.

Having said all that, it is still best to not mix different manufacturers and capacities etc., so if you have the chance - get 2 more of the ones you already have, or a completely new set to replace the old ones.

You CAN add a different new couple to the existing one, it will work, but every person with some common (computer-related) sense in himself will advise you against it.

As I said in my previous post, if you use that PC for timing critical audio related stuff, be sure to dig up some info about the CL timings before blindly buying sluggish RAMs.

Yes.

You CAN buy them, put them in, and they WILL work fine with the ones you already have.
It's just not "symmetrical", that's what bothers most people, including myself - because it's not clean.

No one really knows what goes on in a mainboard's inner workings, so the safest bet -as said by others before- are two exactly the same as you already have - or a completely new set of 2 or 4 to replace the current ones.
Otherwise "strange things" MIGHT (!) happen for no apparent or even regular and traceable reason, BSODs and stuff like that.

Modern systems should actually be capable of dealing with this sort of RAM mingling, but I wouldn't rely on it.

Ok,thanks
I have ordered the 2x4GB as stated and will add them to the current memory

If I notice any problems I will take out the original 2x2GB and stick with the new 8GB.

current mem is in slots 1 & 2 do I just drop the new mem into slots 3 & 4 or do i need to swap them around or anything?

Many thanks for all your help on what to me is yet another very confusing problem !

Haha, no problem, it took me a while to know what's what, and what's important and what's not. I know it can be really confusing!

I just had a look into you board's manual to be sure. It says:

"You may install varying memory sizes in Channel A and Channel B.
The system maps the total size of the lower-sized channel for the dual-channel configuration.
Any excess memory from the higher-sized channel is then mapped for single-channel operation."

In other words: with 4GB now and 8GB to come, you'll have the 4GB you've got now plus the first 4GB of the new ones for Dual Channel operation, which should be more than enough in most cases, and the last 4GB of the new RAMs will be used in Single Channel mode, so that part of memory will be accessed a little slower.

For proper and fast Dual Channel operation, you need to pop one set into the DIMM_A1 and DIMM_B1 slots, and the other ones into the DIMM_A2 and DIMM_B2 slots.

So they'll actually be sort-of "shuffled".
(The names are printed on the board beside the slots)

It doesn't matter if you put the new pair in the blue slots and the old ones in the black slots or the other way round, just as long as you don't mix them up.

You write that your memory is currently in Slots 1 & 2, that sounds like your RAM is running in Single Channel mode, so you should check the manual (chapter 2.4 'system memory' --> 2.4.1 'Overview' ) that they're in the right way.

If you download the English manual and look at (Adobe Reader says it's) page 28 of 126, you'll want to put the first pair in like depicted in the lower left ("Two DIMMs (dual-channel operation)") and then put in the remaining couple as in the lower right picture.

Here's the link to the manual:
http://dlcdnet.asus.com/pub/ASUS/mb/LGA1156/P7P55D-E/E5138_P 7P55D-E_manual.zip

Thanks I appreciate your help.

Ok just had a look inside PC and I've made an error.
The current memory is in both the blue sockets A1 & B1 which if I understand your previous post correctly is as it should be and the new memory will go into the black sockets A2 & B2.

So looking from left to right once the new memory is installed it should be
Black A2 4GB - Blue A1 2GB - Black B2 4GB - Blue B1 2GB and no other settings to be made or changed.

No problem, that what a forum's for.

Exactly, that's just how it should be.

Just ordered it for £40.39 delivered which seems ok.

Really appreciate your help, I might have got there in the end by myself, but it would have been more by luck than judgement thats for sure

Cheers'n'Beers !

Nothing's really changed since the birth of the PC and in many ways it's gotten worse, not better as they have tried to improve things.

The problem is this:

The are maybe half a dozen firms that make the memory dimms and then another half dozen make the IC controllers for the memory sticks. Then a bunch of 3rd party firms cherry pick at each price point and make dimm/ic combos which is what the wider market sees as memory.

On the motherboard side of things AMD's got a short pipeline from the CPU to the memory which is how it's always been, but Intel has taken to intrigrating the memory controller for the PC into the CPU die. This is a big part of why they overtook AMD a few years back on the performance side of things but it's also caused some headaches in certain situations.

For the average user using a stock system you have to consider this :
CPU = 1 controller
Matched memory = 2 matched controllers and matched dimm's.

which to be fair at stock works fine pretty much everytime and you can overclock with ease should you have the desire too.

Now consider system two :

Cpu = 1 Controller
unmatched memory = 2 unmatched controllers and dimms from two firms.

So in that instance the CPU controller may get tripped up by having to speak to 2 different controllers that are babbling away without talking properly between themselfs... and in a even worse case senario your looking at missmatched dimms that are spitting the data back out at slightly wrong clock timings which would cause a desync.

Want to add two more sticks of memory that arn't matched? Sure thats' another 4 potential problems to multiply the issue with.

Starting to see where the issues may come from?

Thankfully the CPU memory controller is fairly good at handling this sort of stuff, at least at stock speeds and it'll manage the flow of infomation coming from the memory buss by dropping the clocks to both of them sync nicely... unless you start overclocking the CPU which can cause all sorts of memory related issues these days due to current design.... That however is another rant.

So what is ideal? All the memory from the same batch if they have all the Dimms from the same batch and all the IC's from the same batch which is kinda the point of matched pairs you see out there. You can buy singles from the same box but even then they could have sourced IC's and Dimms from 2 or 3 different suppliers in the same week and mixed them up, which can be a headache down the line.

TL;DR Buy all your memory at the same time if your overclocking or otherwise be prepared to run at stock should problems develop when you mix them up. If your running at stock already and upgrading then you should be fine if you get the speeds/CAS settings roughly the same and set it up right in the bios.