Old 4GB 665mhz RAM with new 1600mhz ram ? ( HELP! )

ryan161200 · Mar 13, 2015

Hello everyone so i'm going to get some new 1600mhz ram and i actually have 665mhz 4GB ram, so i wanted to know if i buy 4gb of new ram ( 1600mhz ) and put it with my old one ( 665mhz ) will it work ?
i actually want to have 8gb of ram, do i need to remove old ram and get only the new ?
adding new ram on old is compatible ?
please answer me, it will be very helpful because i'd really like to keep my actual ram and just add 4gb instead of buying 8gb.

thanks!

Dark Lord of Tech · Mar 13, 2015

ryan161200 :

Don't bother with the old ram , you want 2 identical new modules for the best performance.

ryan161200 · Mar 13, 2015

Yeah but i want to know if it will be 8gb of ram if i add to the old 4gb new 4gb

Dark Lord of Tech · Mar 13, 2015

Don't bother with the old ram it won't be compatible.

ryan161200 · Mar 13, 2015

so i need to buy 8gb and throw the old 4gb ?

Dark Lord of Tech · Mar 13, 2015

Buy 2 - 4gb sticks , don't use the old.

ryan161200 · Mar 13, 2015

okay so it isn't compatible

Dark Lord of Tech · Mar 13, 2015

No it's not.

giantbucket · Mar 13, 2015

is the old ram DDR3 just like the new ram??? if they're both DDR3 you can mix them - it's not ideal but it's usually fine. if they're both DDR2, then you can probably mix as well. but you won't be able to mix a DDR2 with a DDR3.

ryan161200 · Mar 14, 2015

giantbucket, yeah the old ram is ddr3 too like the new one, but are you sure i can mix the 665mhz with the 1600mhz ? cuz i have to know then i'll buy less new ram

giantbucket · Mar 14, 2015

pretty sure your DDR3 667 is actually DDR3-1333, so you should be able to buy an 8G of DDR3-1333 to match it. if you run a program like CPU-Z, the memory tab will indicate the numbers, and you can take those to the shop and if they're properly educated, they can match the 8G to the existing 4G so that you don't lose anything.

PC3-10600 = DDR3-1333 which sometimes has the 665MHz spec stuck to it just to confuse things

I don't think there ever was a DDR3-665 module made.

Dark Lord of Tech · Mar 14, 2015

Just use the new 1600 pair , so that it won't be downclocked to your old 1333 speed.

giantbucket · Mar 14, 2015

that's one option - max performance.
the other option is for cost-effectiveness and not throwing away perfectly good parts.

ryan161200 · Mar 15, 2015

here is a picture of the ram informations

giantbucket · Mar 15, 2015

ok, so it's a DDR3-1333 CL9 1.5V module. should be dead easy to find a matching 8G module so that you get 12G total ram. that is if you want to keep your current ram and just add capacity.

the other option is to replace it with as much DDR3-1600 CL9 1.5V (or 1.35V) as you can afford.

heck, you can probably run your current DDR3-1333 and buy a DDR3-1600 CL9 1.5V and together they'll just run as -1333 (run at the slower speed of the two). this only kind of makes sense if the -1600 module is cheaper than the -1333 module, or if you plan to one day replace the current -1333 with another -1600 doing the upgrade in stages.

personally, I'd just add 8G of DDR3-1333 CL9 1.5V module. but maybe I'm biased since that's exactly what I need to do on my Dell laptop.

ryan161200 · Mar 15, 2015

giantbucket i can get only the 1600mhz because in my country in the stores there is only 1600mhz 8GB ( like corsair, adata xpg, ect ) there is no a big variety ! ^^ and i can't order online

so if i buy 2x4 ddr3-1600mhz and put them in dual channel with the old ones in dual channel, i would get 12 GB ?
PS: i'll have a motherboard with 4 slots, so i put the both 2x4 1600mhz in dual channel ( black ) and the both old one in dual channel ( white ) ?? and i will get 12gb ?
thanks!

giantbucket · Mar 15, 2015

if you put 2x4G 1600 (new) together with 1x4G 1333 (old), then you'll get 12G but it will probably drop down to single channel mode. i haven't tried it myself but stuff i've read says you can see a slight reduction in performance when using single channel in certain applications (and in other apps, no real difference). but it's still 12G worth of ram.

if it completely fails to even boot, then you can just remove the old one and forget about it, and just use the new ones. you'll have "only" 8G but it's still enough and will work in proper dual channel.

ryan161200 · Mar 16, 2015

okay! thanks

DavidVlogs · Jun 8, 2017

ryan161200 :

I also am wanting to add 4gb 1600mhz to my 665mhz ram so will it be compatible?

Old 4GB 665mhz RAM with new 1600mhz ram ? ( HELP! )

Reputable

Retired Moderator

Reputable

Retired Moderator

Reputable

Retired Moderator

Reputable

Retired Moderator

Dignified

Reputable

Dignified

Retired Moderator

Dignified

Reputable

Dignified

Reputable

Dignified

Reputable

Prominent

Share this page