Mixing Ram Sizes?

[elcid79]

Just bought a new PC and it came with 8gb (4gbx2) of Viper III 1866 ram. I want to upgrade it in the near future, is it possible to put 2 8gb sticks in there also? I don't think that it matters too much but it has been years since I built my last PC.

Cheers,

J

 

[Ajay57]

Well as the members would say a lot depends what is your Mobo and your OS that you are using? And by the way welcome to the Forums and can you please give us some more information to go on! Thanks J.

 

[elcid79]

Thanks,

I wound up going with an
AMD 8350
Gigabyte GA-970a-UD3 Mainboard
and a AMD7770 Fx card.


Probably going to put Windows 8 on it, and I may dual boot a linux build.

Thanks for the help. Its fun to get back into desktops. I havn't had one in years, traveling so much for work.

 

[Ajay57]

It say's you can use up to 32 GB of memory on that Board, but that depends what OS you are running. I.E. Win 7 64 bit will support up to 16 GB the higher OS 32 GB and upwards to 64 GB. So take a look at the post and see what you want in Ram, but i think nothing to stop you. Putting 16 in that board so long as its compatible with it.

1, http://uk.gigabyte.com/products/product-page.aspx?pid=3907#sp

Just read the post above if you need anymore help just come back to us. And there is memory PDF Download to your area so try that and check your RAM!

Thanks ED, yes he needs to buy a new set of ram @ 16 GB or 2 x 8 GB. But as EarthDog said do not mix and match ram!

 

[EarthDog]

The point is mixing and matching. Since he already has 8gb im going to assume he has a proper os that supports it and the capacity he is upgrading to..

That said, not a good idea to mix and match. Speeds, timings, and voltages all need yo match.
but even then there is a chance it wont be stable.

 

[elcid79]

So I was flipping through the approved vendors list and I noted this:

"Only one DIMM per channel is supported for DDR3-1866MHz and higher speed as using an AM3+ CPU"

So as I understand it, my mb has 4 Ram slots, I can only use 2 dimms of RAM at 1866 or above. I could however use all 4 Dimms if I underclocked the ram. Would it be better to Underclock for 26 or 24gb at 1600 or run 8gb at 1866. Further, if I do go with underclocking would I have to purchase the exact same RAM that I all ready have to prevent it from creating problems. Thanks again! You all rock!

 

[elcid79]

Also, with that, would I see better performance with 8gb at 1866 or 16gb at 1600... Cheers.

 

[sandslash]

It is very, actually the most insignificant gains in overclocking, to overclock the RAM. Your performance increase would be in the single digit percentile numbers, the biggest "improvement" in purely synthetic loads like crushing pi decimals. That being said, if you like crushing pi decimals and want to be 1,2% faster than you were, sure get fast RAM, otherwise don't bother, unless your CPU overclocking is bottlenecked by the RAM that is.

AFAIK the FX-series is quite easy to overclock a bit being multiplier unlocked, so it shouldn't be much of an issue. Just don't buy anything slower than 1600 so the other pair shouldn't bottleneck your 1866 too much.

 

[elcid79]

So should I "Underclock" the 1866, and run 16 or 24 gb at 1600?

 

[sandslash]

Yes. You generally don't have to do that by yourself, as faster RAM is backwards compatible and will just run at the clock speeds of the slower pair. What are you doing that needs such amounts of RAM?