Question about mixing RAM

So I was just curious how much of a loss of performance or how much instability would increase if I mixed two different brands (two different Cas Latencies) in my build?

Right now I have this one:
Newegg.com - G.SKILL 2GB 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10600) Desktop Memory Model F3-10600CL9S-2GBNT
Cas Latency/Timing - 9-9-9-24

But I was thinking of picking up this one:
2.0 GB Super Talent DDR3 PC3-10600 1333Mhz 240-Pin Memory with Black Heatsink (W1333UB2G8/WA133UB2G8) - DDR3 1333MHz (PC3-10600)
Cas Latency/Timing - 8-8-8-24

both same voltage (1.5V)

I've read that it isn't suggested but the threads that said that were 5 years old (google searched) so is that still the case? should I just go and buy the ones online instead of heading to the computer store later this afternoon?

oh and then I was just curious also about two of the slots on my mobo...

it says I can overclock to 1800mhz in those two slots but what about the other two slots? can they be used with slower speeds and not mess up the computer?

also, I'd like to know how to install that 1800mhz...do I need to buy that speed or do I need to buy a 1333mhz (fastest my mobo states besides the 1800 (OC)) and overclock it to 1800?

and if I overclock it, I'll probably be wanting sticks of memory that have heatsinks, right?

Mixing memory is always a crapshoot. Sometimes it works fine, sometimes not at all, sometimes it's pretty much OK with random problems here and there. You takes your chances and gets what you gets.

okami 11x said:

...it says I can overclock to 1800mhz in those two slots but what about the other two slots? can they be used with slower speeds and not mess up the computer?

That's a new one on me. Two high-speed and two low-speed slots on the same board?

also, I'd like to know how to install that 1800mhz...do I need to buy that speed or do I need to buy a 1333mhz (fastest my mobo states besides the 1800 (OC)) and overclock it to 1800?

It's letting you use RAM rated higher than the stock speed of the FSB. This gives you room for a little more overclocking. If you're mixing RAM you'll likely find that the faster pair has to slow down for the slower pair. (See the first sentence in this post.)

Keep in mind that RAM (and CPU's, for that matter) are manufactured in batches. After they are made they are tested. The higher rated parts get sold as higher-specced parts and the slackers as low-grade parts. If yields are good (meaning that a high percentage of the parts test well) the manufacturer may mark some of them as lower-specced parts for marketing purposes just so they have some to sell. For instance, if you've ever seen hobbyists raving about a certain stepping of a CPU it probably means that many of them are marked lower than their true capability and are great overclockers. RAM is often the same way, as are video cards.

You can't count on anything other than that the part will run at the speed at which it is rated. If you can squeeze a little (or a lot) more out of it, great.

and if I overclock it, I'll probably be wanting sticks of memory that have heatsinks, right?

Most RAM does nowadays. If it doesn't, you can get add-on heatspreaders, though you often might as well have paid for better RAM to begin with.

profdlp said:

That's a new one on me. Two high-speed and two low-speed slots on the same board?

I could just be confused myself. If that's not something that's been heard of before, then I probably just messed up reading the specs.

So I think I'll just wait and get the same memory.

However, I did just realize I have this memory on my wishlist on Newegg

Newegg.com - G.SKILL Ripjaws Series 4GB 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Desktop Memory Model F3-10666CL9S-4GBRL

It has the same specs except for one small detail. On the Timing, it's 9-9-9-24-2N
What does the 2N mean? it's not on the memory I have now so would these two be compatible?

Oh and I've heard people saying don't mix RAM sticks with different sizes (i.e. 1 stick of 2gb and 1 stick of 4gb) because the larger size is brought down by the smaller one. Is that true? or can I just order a 4gb stick in the future and slap it down in the case? And if it's fine, can I dual channel two different sizes or do they have to be exactly the same?

sorry for all the questions, I'm just a n00b when it comes to RAM since I always thought that RAM was RAM

another question lol

which number is better for timings/CL? a higher or lower? (i.e. 4-4-4-12 vs. 9-9-9-24)

Found this note on the spec sheet for your board:

(Note 2) To reach DDR3 1800MHz or above, you must install two memory modules and install them in the DDR3_3 and DDR3_4 memory sockets.

I think it's due to the limitations of the chipset and has to do with the same thing in the next part about 1T and 2T. Basically, the chipset is limited in data paths and will run all the RAM slower if using more than two slots.

okami 11x said:

...It has the same specs except for one small detail. On the Timing, it's 9-9-9-24-2N
What does the 2N mean?...

That's the command rate, meaning the time it takes to send a signal to the memory module. If you've poked around in your BIOS you may have seen a RAM timing setting like 1T and 2T. The "N" is the same thing. My last AMD system required you to run at 2T if using more than one pair of sticks in any case.

Oh and I've heard people saying don't mix RAM sticks with different sizes (i.e. 1 stick of 2gb and 1 stick of 4gb) because the larger size is brought down by the smaller one. Is that true? or can I just order a 4gb stick in the future and slap it down in the case? And if it's fine, can I dual channel two different sizes or do they have to be exactly the same?

You'll lose the Dual-Channel capability if you use mismatched pairs in the wrong slots. I won't promise you it's true in all cases (because I don't know... ), but I have a system with a pair of 512MB sticks and another pair of 256MB sticks running in Dual-Channel just fine.

sorry for all the questions, I'm just a n00b when it comes to RAM since I always thought that RAM was RAM

Questions are fine, asking them is how the experts became experts. You are well on your way yourself. :)

PS: Saw your last question as I was typing this. Lower numbers are better.

profdlp said:

Basically, the chipset is limited in data paths and will run all the RAM slower if using more than two slots.

So basically, if I use all four slots, my RAM will run slower than if I only used 2 slots?

profdlp said:

You'll lose the Dual-Channel capability if you use mismatched pairs in the wrong slots.

so I have 2 blue slots and 2 white slots (I assume that's to make it easier to spot which ones can do Dual Channel together), but if I put a 2gb stick in one of the blues, and a 4gb stick in the other blue, there isn't going to be a dual channel then, if I understand correctly. It will run the same as if I put the 2gb stick in a blue and the 4gb stick in a white, no?

profdlp said:

PS: Saw your last question as I was typing this. Lower numbers are better.

That's what I assumed :) I just wanted to know for sure


So as my mobo was advertised, can all of my slots be overclocked to 1800+ (as it says directly on the mobo)? and do I just buy 1333 and oc it to 1800? or do I buy 1800? (my gut is that if I bought 1800, it wouldn't work)

oh and I'll make sure to keep asking the questions

Wishmaster said:

I wouldnt advise mixing and matching RAM. True, sometimes you can get it to work, But in general its not really a good idea.
Even though the basic specs, (speed, latency, voltage) all look the same, theres many smaller sub timings etc that could be quite differnt, depending on the type of RAM it is.

so even though I'd be buying the same brand but different model and all the basic specs are the same, you'd suggest not mixing them then?

so basically it'd be better to just put the 4gb ripjaw I posted earlier by itself then having the one I have in my system right now plus the ripjaw?

okami 11x said:

So basically, if I use all four slots, my RAM will run slower than if I only used 2 slots?

Wishmaster put it better than I did. More sticks equals more stress on the system, meaning less chance of higher speed.

so I have 2 blue slots and 2 white slots (I assume that's to make it easier to spot which ones can do Dual Channel together), but if I put a 2gb stick in one of the blues, and a 4gb stick in the other blue, there isn't going to be a dual channel then, if I understand correctly. It will run the same as if I put the 2gb stick in a blue and the 4gb stick in a white, no?

Check in the manual for which slots are paired, it's not always obvious by color code.

do I just buy 1333 and oc it to 1800? or do I buy 1800? (my gut is that if I bought 1800, it wouldn't work)

Higher-rated RAM will work at a lower speed if necessary. I wouldn't count on getting 1333 to run at 1800. If the 1333 was able to run at 1800, chances are the manufacturer would sell it at that speed for a higher price. (Go back and read what I mentioned before about "batches".)

As Wishmaster reminded you, see the first line I wrote in Post #3. Mismatched RAM is a crapshoot. If you want to be as sure as possible that it's going to work you might want to just get two new sticks at a higher capacity. Your specs say you have 2GB now. The sticks you linked to are 4GB each. I'd think that 8GB total would set you up quite nicely.

EDIT: Just saw your last post. If you get the two 4GB sticks you can always try all four sticks together. If it doesn't work just yank the old ones out. I don't think you'll see any difference between 8GB and 10GB either way.