OK to mix RAM as long as they have the same speed, capacity, timings, and voltage?

[Dankk]

I'm using two sticks of Corsair memory that are different models, but very similar to each other. Here are two CPU-Z screenshots that show each module. Do you think it's OK to mix these?

Sure, they have different JEDEC values, and a different "max bandwidth" rating (not sure how meaningful that is); but ultimately, they both have the same capacity, they both have the same speed (800MHz, or 1600MHz since it's dual channel), they both have the same timings (10-10-10-27), and they both have the same voltage (1.5v).

I don't think my motherboard is under-clocking or under-powering either of these to match the other. If you look up the specs for both models, you'll see that they're running at the exact same specs as recommended from the manufacturer.

Just checking because I know mixing RAM is typically regarded as a dumb move, but I'm guessing since these are so close to each other I'm actually fine? let me know if I'm wrong.

 

[Zodiark1593]

http://www.intel.com/content/www/us/en/support/boards-and-kits/000005657.html

In short, yes, you can run your sticks in dual channel. It's probably the mobo is running them at equal speeds.

 

[Deders]

I expect you will be fine. I've used mixed ram in some builds with no problems, I checked the same details you did.

There are however a myriad of subtimings that may cause some issues, with any luck your motherboard's internal logic will have found a way to set these so everything is in tune.

Modern mobo's come with something called memory training and will adjust these sub timings on bootup, depending on a variety of factors. It's best to leave this on.

Older mobo's you might have to do a full bios reset or unplug it and remove the battery for half an hour or so in order for the bios to click on and redo it's memory testing.

 

[LTC8K6]

It's the Memory tab that shows the actual speed that the memory is currently set to.

The SPD tab just shows the SPD info from each stick.

If the Memory tab shows the speed you are looking for, then you are good.

 

[dave_the_nerd]

Generally yes, it's ok, with two caveats:

1) Some motherboards won't run 4 sticks as fast as they can run 2 sticks, regardless of what speed the RAM is rated at.
2) If you're not running the ram w/in spec (so, if you're overclocking) mismatched can be pickier.

 

[nerp]

It should be fine. I made a point of buying identical memory from Crucial and it turns out one has Hynix chips and the other has Micron. So even buying the same memory will give you the same timings but not necessarily the same exact sticks of memory.

 

[DigDog]

since nobody has pointed this out yet..

RAM does not have "speed". or "timings". or even "voltage".

What it does have, is ideal voltage, maximum speed, and maximum timings, same way that a CPU has an ideal voltage and a recommended speed, which as well all well know, it's never the case.

So, ALL ram can run at any voltage (more or less), but depending on this voltage you might or might not be able to push it to certain frequencies, or lower than certain timings.

The fact that ram auto-detects the manufacturer's recommended speed is not really due to the "ram" itself, but something which they stick on the module (i dont really know everything here, so ..).

In short, you get a module which has "potential", to run at lower (and higher_ voltages, which can hit such and such a frequency ...and so on.

When you run two different brands / models of ram, you won't be able to use the auto-detect. The motherboard freaks out if you tell her you're using two kinds, just like if you told your ma' you are dating two girls.

But, if you run the ram at "reasonable" settings, ALL ram will run the same. In fact, most high-end ram (with high voltages and very high speed) will not auto-detect correctly on most mobos, and it needs to be manually set to those speeds.

 

[h9826790]

In general, mixing different size, speed, timing...DDR 3 RAM is not an issue. The system should able to automatically pick the highest possible speed (the lowest between the sticks), and run on that speed. e.g. Almost all 1600 RAM can run at 1333, 1066 etc.

If not, manually set the parameter that according to the "slowest" stick.

The only limitation so far I know is that you cannot mix RDIMM with UDIMM.