Confused about DDR3...

[frowertr]

Wanting to put together a new AM3 890FX system together. Been looking at getting this ASRock board: http://www.newegg.com/Product/Produc...82E16813157196

According to the motherboard specs its supports DDR3 1800(OC)/1600(OC)/1333/1066/800.

Now I won't be doing any overclocking. So what speed DDR3 do I need to get. Is 1800 and 1600 only useful if overclocking? Would 1333 be what I would want to shoot for?

I used to build systems back in the day but have been out of the loop for a while...

Thanks guys!

 

[Ben90]

DDR3-1333 is the max a Phenom II officially supports. If you are planning on keeping this system for a while I would probably just get 1333. If you are the type of person who would like to drop in a new processor later down the road I would consider 1600@1.5v as long as there isn't too much of a premium.

 

[frowertr]

DDR3-1333 is the max a Phenom II officially supports. If you are planning on keeping this system for a while I would probably just get 1333. If you are the type of person who would like to drop in a new processor later down the road I would consider 1600@1.5v as long as there isn't too much of a premium.

Thank you, Ben. I may just go with 1333 to keep everything easy as possible.

Why do you suggest possibly going with 1600 for "future proofing". Are you thinking future Phenom II's will eventually support PC-1600??

 

[Scotteq]

If you dont' plan on overclocking (ever), then stick with the 1333 DIMMS with the tightest timings you can find.

If you *do* plan on overlocking, or want to allow for it with little/no hardware changes later on, then you could/should buy faster memory. Otherwise, (to borrow a phrase) there's 'no improvement in Userland' for the extra money you spent.

 

[lopri]

There are 4 dividers available for AM3 CPUs, which are:

DDR3-800, or 3:6 (1:2) -> HTT (200) x 6/3 x 2
DDR3-1066, or 3:8 -> HTT (200) x 8/3 x 2
DDR3-1333, or 3:10 -> HTT (200) x 10/3 x 2
DDR3-1600, or 3:12 (1:4) -> HTT (200) x 12/3 x 2

Beyond DDR3-1600 can only be achieved by overclocking HTT. For example, if you overclock the HTT to 250 at memory set to 3:10 ratio (DDR3-1333 stock), your memory will be at DDR3-1666. (=250 x 10/3 x 2). If you set the ratio to 3:12 (DDR3-1600 stock), you get DDR3-2000 (=250 x 12/3 x 2)

Memory overclocking greatly depends on the choice of CPU and the board. In general newer steppings fare better than older stepping CPUs.

 

[Blain]

Just remember to buy DDR3 rated to run at 1.5v or less.

 

[frowertr]

Ok, so bottom line is if I don't want to overclock, then I need to stick with PC-1333 and make sure its 1.5v or less.

I saw that Gskill had some 1.35v memory on Newegg that was PC-1333. I'll check that out. Love the idea of reduced energy and heat...

 

[Rifter]

Also something to consider since the price is not alot differnt and you might find a good sale price on some 1600 is that you can always get 1600 ram and run it at 1333 with tighter timings and less voltage.