Double Dual Channel on P5Q Deluxe?

[Neil27]

Hello,

I am looking to add to the 2x1GB sticks running in A1 and A2 slots i have in my P5Q. I am wondering if the B1 and B2 slots will also run in dual channel if i got 2 more 1gig sticks.

The mannal states:

"You may install varying memory sizes in channel A and 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 the mapped for ingle channel operation."

So would it be better for me to buy 2x1gb of the current ram brand i own:
http://www.cleverboxes.com/Product/112-TWIN2X2048-8500C5D

Or for a similar price go for 2x2gb:
http://www.lambda-tek.com/componentshop/index.pl?prodID=1525843

 

[jaquith]

DDR2 1066 5-5-5-15 @ 2.1V (2X1GB) Dominator TWIN2X2048-8500C5D
DDR2 1066 5-5-5-15 @ 1.8V (2X2GB) Kingston KHX8500D2K2/4G
==========================
DDR2 1066 5-5-5-15 @ 1.95+V (6GB)** ; you may have a voltage issue.

Ideally, see if you can find TWIN2X4096-8500C5D (2X2GB) http://www.lambda-tek.com/componentshop/index.pl?searchString=TWIN2X4096-8500C5D&go=go

**In addition, anything >4GB requires a 64-bit OS.

 

[Neil27]

Thanks for the reply, I didnt notice the voltage difference, I think i will play it safe and go with some more corsair dominator ram...

If i get another 2x1gb of the corsair will it have a speed advantage (as in, run as a second dual channel on the motherboard) over getting 2x2gb of corsair?

And i have Win 7 64bit

Thanks!

 

[jaquith]

Whether you have 2X_GB or 4X_GB you're still running in Dual Channel. In a benchmark 2X_GB is faster but nothing you could ever 'feel' or notice. However, 'matching' all the RAM with the same Frequency, CAS timings, and Type often including the same Mfg is 'ideally' the better and safest choice to avoid problems.

If you have the money, 6GB is faster than 4GB in tests. http://www.tomshardware.com/reviews/ram-memory-upgrade,2778-8.html

Good Luck! :

 

[Neil27]

Thanks for your replies, they have been helpful, but i think i do not fully understand how dual channel ram works,

I have 4 slots and my MB manual says it will run the lower sized pair in dual channel, does this mean that the remaining 2 slots can also be a second dual channel if they are the same sized sticks? or can there only be a single 'dual channel'?

 

[jb6684]

Background on RAM:

You should always install 2 sticks that match in size and timings for optimum performance. This is so you RAM will run in Dual Channel mode. And, so that the system will set a CAS & other timings that will work both sticks. And finally, Intel & AMD CPU chips will over clock the best with ONLY two sticks.....

But you can use 4 sticks. The second 2 sticks should match each other. The do NOT have to match size or even the timings of the 1st 2 sticks. This is true since system will run at the timing for the SLOWER pair of sticks. Size doesn't matter at all...

An time you use an odd number of sticks, you'll run Only Single channel which slows your computer down quite a bit.....


To You Specific Question:
There are A1 / B1 lower two slots ; A Channel and B Channel (if you install one in A and one in B that "Dual Channel")

and A2 / B2 upper two slots ; A Channel and B Channel they just provide additional space for RAM NOT more Channels....

 

[jaquith]

You do want the RAM to have the same: Frequency, CAS Timings, Voltage and Type. Your MOBO allows per pg 2-2 for the sticks to be different sizes.

The CPU IMC {Integrated Memory Controller}, in your case, can fully access two channels with up to two sticks {DIMMs} per channel. //Some consumer MOBO's are Dual, Tri and soon Quad Channel.//

In the case of 2X1GB and 2X2GB, both Channel A = 3GB + Channel B = 3GB are identical in size so an 'unequal' size doesn't pertain. Install the Matched Sets per the same color DIMM:

CPU: | 1GB | 2GB | 1GB | 2GB |

Also, if you reread 2.4.2 then you'll understand why I linked the sets I did above.

Good Luck!

 

[Neil27]

Thanks For the replies, I am going to purchase:
http://www.lambda-tek.com/componentshop/index.pl?searchString=TWIN2X4096-8500C5D&go=go

But jaquith, wouldnt the best way to install the memory be:

CPU | 1GB | 1GB | 2GB |2GB|?

according to 2.4.1

The first 2 slots are channel A and second 2 are B

so the paired sticks would run better like i have stated, no?

 

[jaquith]

If you did then you're loading up Channel A = 2GB and Channel B = 4GB and according to the manual you'd yield 4GB with the BIOS shutting down 2G on Channel B.

Reread 2.4.2 - the part that starts "You may install varying memory sizes..."

Dual Channel uses the 'A' & 'B' DIMM banks, and A > B = B*2, A < B = A*2, A = B = A + B or A*2 or B*2.

 

[Neil27]

Ah yes. makes sense now, thanks for all the help.

 

[Neil27]

Hi jaquith

Sorry for asking you so many questions, but where are you getting your info that the kingston RAM i mentioned at the start of this thread runs at 1.8v?

On here it states 2.2-2.3v

http://www.kingston.com/hyperx/products/khx_ddr2.asp

 

[jaquith]

Duh, in the haste I posted the correct timings but I looked at the wrong voltage, and with all the links I thought I posted the info ; Data Sheet link http://www.valueram.com/datasheets/KHX8500D2K2_4G.pdf

DDR2 1066 5-5-5-15 @ 2.1V (2X1GB) Dominator TWIN2X2048-8500C5D
DDR2 1066 5-5-5-15 @ 2.2V [strike]1.8V[/strike] (2X2GB) Kingston KHX8500D2K2/4G
==========================
DDR2 1066 5-5-5-15 @ 2.1V~2.2V [strike]1.95+V[/strike] (6GB)** ; you may have a voltage issue

Oopsy, with the voltage on the Kingston, but you are still much better off the Match the RAM IC with simualr family of Corsairs.