Adding more DDR3 RAM - Dual Channel

[bazz5313]

Hi, I have a Gigabyte GA-970A-DS3P mobo - currently has 2 x 4gb sticks of DDR3 1600 ram. I want to upgrade to 16gb. Could I add 1 x 8gb, or does it have to be another 2 x 4gb sticks. Not sure how this dual channel thing works. Thanks

 

[bazz5313]

I have found out I can use 2 x 4gb sticks for my other dual channel, as long as the 2 new sticks I am putting in the dual channel are the same. CPU-Z shows my current sticks as DDR3 1600MHZ 9 9 9 24 (CAS LATENCY, RAS TO CAS DELAY, RAS PRECHARGE, CYCLE TIME). Do I need to get the same timings 9 9 9 24 for the new 2 x 4gb sticks? as I have seen 4gb sticks for sale with different timings - eg. 11 11 11 30. .. thanks

 

[Karadjgne]

Yes, you can use 1x8Gb with 2x4Gb and have full dual channel.
4-X-4-8 or 4-8-4-X will see 8Gb in channel A, and 8Gb in channel B.
If you mix that up and do something like 4-X-8-4, then you'll be in flex mode which shows 12Gb in A and 4Gb in B, so the first 4Gb and 4Gb from the 8Gb stick will be in dual channel, with the last 4Gb stick and the remaining 4Gb of 8Gb will be single channel.

Ram will run at slowest speed and timings, so if you have 8Gb cas11 1600 and 8Gb cas9 1600, the whole thing will run at 16Gb cas11 1600.

The biggest worry about mixing kits is compatability. The closer you can get to identical match, the smaller the possibility of incompatibility. Usually. The only guarantee with mixed ram is there is no guarantees. It may work, it may not, it may need extra voltage, it may need relaxing timings further or any combination to get it to work right. Simply no correct or positive answer until tried, which is why ppl claim you shouldn't mix ram, you may not be able to return it or have to return it half a dozen times to get ram that plays nice. Very big hassle.

 

[bazz5313]

Thanks for advice. Have just added 2 x 4gb sticks, no issues. However - one query - CPUZ shows DRAM Frequency 669.6Mhz (has always shown that, prior to the extra 2 x 4gb), and I just found out that means my ram is running at 1333Mhz, not 1600Mhz. Should I change it in BIOS, and if so do I just enable XMP profile? (I read somewhere that is all I need to do, but wasnt 100 percent sure). My ram is all 1.5v. -- Or, is it worth it ?? - will I see any difference increasing the ram speed - Main use of PC is gaming. Thanks

 

[sizzling]

You should only need to enable XMP.

 

[bazz5313]

Just checked BIOS - XMP is set to Profile 1.
System memory multiplier is 8.00 - Auto
Memory Mhz is 1334Mhz - 1600Mhz
Basically the end column reads ** Profile 1, Auto, 1600MHZ

Only option with XMP is Disabled or Profile 1 (wont let me disable it).
Think I clicked on Multiplier (set to Auto) and options are Auto, Quick, Expert. Didnt want to mess around with them at present. Any suggestions
p.s. quick edit, the above settings are what the BIOS was set to when I checked it. I havent changed anything.