Is it okay if I use different RAM stick sizes?

Any good motherboard should easily be able to handle mixing ram. Even cheap boards nowadays can do it. I've mixed different speeds, sizes, and brands with success on cheap boardd like biostar.

Any additional stress on the memory controller is purely hypothetical and modern systems are easily able to mitigate most issues. While most old computer pro's don't like the idea, mixing ram isn't an issue anymore, so long as you motherboard supports the ram speed.

Thor220, can I refer all the folks having problems with mixed sets to you to get straightened out, I've been here but about a month and pick up two or more a day having problems with mixed sticks, have also done support on the GSkill forums for the past few years and that's the biggest problem in the DRAM world, second biggest is BIOSs that aren't ready for large /high freq sets, how often do you do this and I'd guess basically with maybe 1066/1333 which often do work (though often one doesn't get full potential from the DRAM...and your wrong, mixing DRAM didn't use to be the issue it is today, yesterdays DRAM was staid and simple, DDR, DDR2 and early DDR3....you obviously don't deal with good DRAM or high freq DRAM, and don't know/understand MCs - if it's purely hypothetical, then why say, are AMD FX CPUs rated (supposedly up to 1866 at 1 stick per channel, 1600 for for four sticks of single rank and only 1333 for 4 sticks of dual rank - In all your great wisdom are you saying that's hypothetical? I use AMD as an example because they HATE to say anything negative about their own product, but it's right here:

http://support.amd.com/us/kbarticles/Pages/ddr3memoryfrequencyguide.aspx

Hypothetical, hah! Can you kindly explain this? It's 'experts' like you that cause people in the forums problems with your baseless 'advice' and comments....so will it be OK to have these folks taking your advice PM you to fix there problems?

Aoneptune,

I apologize for disrupting your thread, but these people drive me crazy and I am an old computer pro, and have probably forgotten more about systems than this Thor220 knows

Can I have these folks PM you also? at 1333 and under, quite often yes, at 1600 and above, more often No

My experience is hands on, not from forums. I have put different sticks of ram, different speeds of ram, and different sizes of ram into multiple motherboards, spanning a large swath of manufacturers. An issue is rare, more coming from bad sticks. Obviously the ideal situation is to use the same size, speed, and brand but if a better option is available from using varied sticks, I would take it.

Onto your amd link, amd never rated fx for 1866. They only officially support 1600. Not to mention the article never mentions anything that would detriment running different sticks. If you can disprove by way of actual proof that would be great but right now you might as well be quoting a dead president.

Just because people have issues with mixed sticks does not mean it's due to just that. Why are there more people with issue on mixed sticks? Maybe because the vast majority of people purchase memory a second time, often not the same as the original. Next time someone disagrees with your opinion on a forum you should come out with a more polite tone instead of being so condescending. This is the internet, someone is bound to contradict your own opinions.

aoneptune

As mentioned in my earlier post, if you'd like to try yes, feel free, it may work, and as mentioned you'll have 8GB in dual channel mode and 4 GB in single...and as I mentioned, if there is a problem, I'll be happy to help, I've had a lot of experience in dealing with these matters, just wanted you to be aware of the pitfalls you may encounter as many others here in the forums have encountered. A lot of folks don't like being frustrated if they do run into problems, others seem to revel in it and the tinkering around that may be needed to tune the sticks to run optimally (actually I know I do, but preferably when I have the rig hands on, it (at times) drives me crazy doing it back and forth through the forums

Thor220

Yes I do get upset when I see these suggestions, you mention you've done this several times, and may well have, though I'm guessing the bulk of it (DDR3 anyway) has been with 1333 and prob 1600 sticks, or if you often work with higher end DRAM (1600 and up and/or tighter timings) then you have a better knowledge of advanced timings than others and are comfortable adjusting those and voltages as needed...most members here aren't that skilled, they want to plug in the DRAM and have it work, mention adjusting voltages/timings and they are lost.

You also mention 'more coming from bad sticks', in talks with the folks at GSkill, Corsair, Mushkin and others the vast majority of sticks that are RMAed are often perfectly fine, and the problem was people trying to mix the sticks with those they already had and since things worked fine before, they blame the new sticks - this is especially true w/ 1600 and and up, people have heard of XMP and figure if they turn it on it will work fine - but XMP is programmed by the set of sticks as packaged, not by the individual stick, if that's the way things 'Really' worked they all they would sell is 1 stick packages and make much more money....Why? Each package consist of of sticks that have been tested to work together as a set, it takes a lot of time to test all the sticks and package them....the sticks in a package are tested to work together, tolerances are so tight, you might pull 20 consecutive sticks out of a production lot, and only find 4 that work together and play nice to make one 4 stick set, getting 2 sticks to play nice is easier, three a little harder, 4 mentioned 6 harder and 8 hardest yet. This problem is also expounded on with higher freq sticks that are even harder to pair up and put together sets that will play nice with each other.

XMP is mentioned above, and as you prob know only applies to sticks 1600 and up, per the Intel spec, so as an example if you take a set of 1600 (2x4GB) and run under XMP, if you look in the Advanced/secondary timings you'll prob see a tRFC (Refresh Cycle Time) of 128...however the same model of sticks in a 4x4GB package will require a tRFC of 208....occasionally the BIOS may/might auto adjust the tRFC to at, or (most likely near) what is actually required, also if under Auto it will also often adjust timings on say a 1600 set that is speced 8-8-8-24 to something at CL9 or even CL10 (even saw a couple here that were set to CL11, which greatly changes performance and often leads to BSODs and other problems that are hard o diagnose, which is why I ask...all to often when I see a problem....'DO you have a single package of DRAM or is it from 2 or more packages' - it's often from two or more and a problem with timings and/or voltages.

These things used to be fairly easy w/ DDR and DDR2, manufacturers adhered to JEDEC standards, but JEDEC has completely lost control w/ DDR3 - specs originally came out taking DDR3 to 1600 as the max - but people wanted faster DRAM, 1866, 2000, 2133 quickly came out and JEDEC was scrambling to set 'standards' and the manufacturers kept raising the pole, to now there are 16GB sticks available and freqs to 3000 and above.

Another problem folks often encounter is looking at a mobo spec is seeing a mobo that 'supports' DRAM up to 2800-3000 so they go out and buy say a st of 2400, and don't take into effect that the CPU HAS TO BE ABLE TO RUN IT, and folks have no idea what their CPU can run. (see my info thread here:

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

People also don't understand what is shown in CPU-Z, another info thread here:

http://www.gskill.us/forum/showthread.php?t=10565

I've been working the support forums at GSkill for about 4 years now and I see these problems every day - (and it's a relatively small forum compared to here, about 30,000 members), but I've found myself helping thousands of people who have mixed sets and often on the advice of 'experts' saying 'Yeah, that's no problem, just add another stick or two, as close as what you can to what you have', then there they are, they've spent money (often mail order) and now how sticks that won't play together, so they have to spend more to mail them back, maybe pay a restocking fee, and still don't have working DRAM (and most don't take into effect, now they have wasted a lot of their own time, if they value their time at $10 and hour, they often exceed the cost of the stick(s) that don't work just in their own time then add in postage, restocking fees, time spent waiting on arrival, time waiting on an exchange, travel (if bought at a store), etc.....in the long run, it's just cheaper to buy a set of what you want (total amount).....Yes, occasionally you'll get a set with a bad stick, but that's far less common then problems encountered from mixing sets/sticks.

In the forums here, I try and take the same approach I do with my clients who want builds, upgrades, repairs, etc and try to offer advice and help the same as I do with clients, and pass along what I've learned from building all these years, consulting, etc
I came here specifically to help a couple of folks from the GSkill forums who were looking for help with DRAM from other manufacturers than GSkill and told me, that there's really nobody here at Tom's that knows DRAM, and in the short time I've been here (about a month), I feel that I've helped a number of people with advice they liked and appreciated, while I normally sort of stick to the Memory and mobo areas, when browsing I' jump into whatever I see of interest or where I see a problem I've encountered (often numerous times) and I try to follow all the threads I jump into...and HELP the folks when needed...unlike many here who seem to be on a quest to earn badges, I've seen numerous folks suggest this, Yeah just add more DRAM and often on Posts where there, not even a CPU or mobo mentioned, How can one offer informed advice when they don't even know the hardware? and they often also ask the OP to be sure to check the best answer/solution thing...yet I basically never see these people jump in and actually try and help get things running, while not thrilled about it, think I've got 3000+ response, and by far (would guess about 75-80% are followup responses to whatever I initially offered - I'm going in and helping through their problems....

I'm not exactly sure how all this badges stuff works, but I am somewhat happy that I think over 75 have picked my responses as a 'Best Answer', but more telling to me is that more and more I am getting PMs from folks asking for advice and saying they don't want to hear junk answers, that too many people here just want to try and tell them what to do as if they know everything.

* Also I brought up AMD as an example of how stress affects the MC, and I feel it's a very telling example, of what/how additional sticks/density can affect the MC...The same happens to Intel CPUs, even though they are much stronger, as an example my 3570K can run 32GB of 2400/10, but that's about it, to run 2666 w/32 it just doesn't stay stable with out additional voltage to the DRAM, the MC and even the vCore, which takes temps higher than I'm comfortable with, however, If I drop to 16GB 2x8GB I can run at 2666 , yet fully populated with 4x4GB sticks (again 4 sticks more stress) it tops at 2600....If I drop to 2x4GB sticks I can run 2800, so stress does play in as a factor.....

Hey guys, what if i mixed 2x 2400mhz 8GB corsair vengeance and 2x 2400mhz 4GB corsair vengeance for 24GB of ram (ram slots in order of 8GB, 4GB, 8GB, 4GB so 2x dual channel)?