why does RAM timings need to be adjusted in some MOBO?

Toggle sidebar Toggle sidebar
P

papercut03

Honorable
Jun 11, 2013
161
0
10,690
I am just wondering, why does some RAM (especially the ones that are not on the mobos QVL list) needs the timings, voltages etc. to be adjusted is it because of compatibility issues? (and im not talking about Overclocking) Also, how can we know if the stick that we are going to buy is 100% compatible with the mobo or just simply "plug and play" and yer good to go? is there any special trick? THANK YOU IN ADVANCE!
 
Sort by date Sort by votes
smorizio

smorizio

Titan
Jan 22, 2010
30,984
9
125,315
With ram most of it now built for intel mb and there xmp profile. Some newer amd mb have xmp profile built into the bios. Amd itsel now starting to make ram with it own type of xmp profile. With ram there a small ic on it that tells the mb the rated speed of the ram. Sometimes do to the ram chips and mb voltage you have to bump up the dram voltage with all dimm slots filled. Sometime the ram vendor was to aggressive on the ram and it not stable under testing intill you slow the timming down. The biggest issue is one module of ram stick may have four or five different ram modules used in it life time. That a mb vendor may sample a set of ram sticks from this weeks lot and find they work fine. The next lot may have anther batch of ram ic and not work till a bios patch is dropped. Big ram vendors like crucial test there ram a lot. Most laptop vendors recommend them for there ram upgrades. Gskill ram some of the ram is hit or miss on some mb.
I had issue with gskill and a sabertooth mb. Crucial ram stood behind tree life time warranty when I had bios bug on p35 mb and 1066 ram. I sent back three or four kits till I found out that the 1066 ram the mb could not run it without causing ram issues. Crucial swapped out the ram for slower 800 for free and the system was stable.
 
Upvote 0 Downvote
Tradesman1

Tradesman1

Legenda in Aeternum
Jun 5, 2013
67,883
40
126,960
There's actually a few issues that come into play, first, when you first install stick, the motherboard defaults to either 1333 or 1600 and sets a generic JEDEC based set of timings which should hopefully match up to default timings in the SPD of the DRAM sticks themselves and should allow you to boot most any stick up...9if the BIOS is well written and some are not), see my QVL info thread here:

http://www.gskill.us/forum/showthread.php?t=10566

Then it can be more difficult, though it shouldn't be, most all sticks 1600 and above now need to be configured to the mobo to run at rated freq, Intel uses XMP as the easy way, and AMD uses it's own style of OCing profiles, most popular is called DOCP (some are even starting to use XMP), this takes a profile off the SPD and offers it to the BIOS which then, if it can sets the sticks up as they should be, this is where problems often occur as the BIOS can't always set the sticks to the optimal timings/settings (which is a BIOS programming thing, which is why you see so many BIOS updates, generally 50-75% or more of BIOS updates are really for DRAM and XMP compatibility)

For basically true 'plug and play' and doing nothing you are limited to 1333 or 1600 if the mobo supports that freq at boot, otherwise with Intel on higher freqs XMP will work, generally with slight adjustments the manufacturer or someone knowledgeable w/ DRAM can provide...I help on support at GSkill and do so because I have found their sticks to be great, and they have knowledgeable techs and field engineers that are in and out of the forums on a daily basis
 
Upvote 0 Downvote
P

papercut03

Honorable
Jun 11, 2013
161
0
10,690


So sometimes even the ones that are on the QVL's list are not reliable? because I saw some RAM with the speed of 1800MHz or 2100MHz included in some of the MOBOs QVL list.

 
Upvote 0 Downvote
Tradesman1

Tradesman1

Legenda in Aeternum
Jun 5, 2013
67,883
40
126,960
Well in their minds, (the mobo makers), yes they work, because they booted up fine at 1333 or 1600, bbut in your example you bought the RAM for 1800 or 2100 (actually prob 1866 or 2133) and that's what you want it to run at (and they advertise that it will run at that), but at times no they won't without manual adjustment, because the mobo makers don't have the BIOS ready for them - (and this drives me crazy, they advertise the freq and say it will work, they put them on the QVL, but if someone has a problem, rather than support what they advertise, they often tell you to call the DRAM maker or even just tell you the DRAM is prob bad/dead)
 
Upvote 0 Downvote
P

papercut03

Honorable
Jun 11, 2013
161
0
10,690


MEHHH sounds like false advertising and passing their wrongdoings to the RAM company D: last question, so I have a RAM that was not on the QVL's list of my mobo. It has a speed of 1866 MHz but my mobo defaults it to 1600 MHz. The bizarre thing is, if I plug both of them (my ram came in a set of two) MEMORY_MANAGEMENT errors shows up. BUT if I only plug in one, my computer becomes stable. I have tried plugging both sticks individually. they will work as an individual but not as a pair. xD
 
Upvote 0 Downvote
P

papercut03

Honorable
Jun 11, 2013
161
0
10,690


Hi! so right now I am running my computer using the RAM that was on my MOBO's QVL list. In the QVL's list, the RAM that I have bought was labeled as 1600MHz however, When I plugged it in, My mobo underclocked it and used 1333MHz. So I have used XMP profiles to run my RAM at 1600MHz. My question is, since on their list, my RAM has 1600MHz does this mean that when they tested the RAM that I have they overclocked it to 1600MHz? or should I just hope that tested it at 1600Mhz since most of the time they test the ram they do not have BIOS? THANK YOU SO MUCH!
 
Upvote 0 Downvote
Tradesman1

Tradesman1

Legenda in Aeternum
Jun 5, 2013
67,883
40
126,960
It was probably tested at 1333....Setting up a BIOS for the most part initially consist of programming it for standard JEDEC settings like your 1600 may be 9-9-9-24, 9-9-9-27 somthhing to that effect, whan a manufacturer puts out a set of 1600 at say 8-9-9-25, there's good chance that wasn' settings programmed to be used by the BIOS, so the BIOS looks at what's on the SPD of the stick in the SPD profile and sees that 8-9-9-25 and the best it might be able to equate to as far as settings it can use is 9-9-9-25 so it set's it to that and it will prob work fine and will show in CPU-Z and elsewhere that it's running at 1600 so folks are happy and never catch that the CL is at 9 instead of the 8 it should be at, if the mobo maker sees the sticks or someone complains about it they MIGHT put it on there list to add an update to the BIOS for 8-9-9-25 or they might not....if you notice and change it, it might not want to run right, so YOU, being ever resourceful check and around and my ask for help or find a thread somewhere that says raise the DRAM voltage by +0.03 and you try that with the tighter CL of 8 and all is REALLY GOOD, itt's running as it should, a couple months down the road, you may do a BIOS update and figure, crap, got to change the CL again and up the DRAM voltage and be surprised to find that with the new BIOS it sets the timings correctly and you no longer need that extra DRAM voltage
 
Upvote 0 Downvote
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Moderators online

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom