DDR2 to DDR3

big.rich1976 · 8 Feb 2010 at 10:58

Hi There,

Quick question regarding DDR3 ram, I currently have DDR2 667mhz ram, Quite old but works well and this is teamed up with a E2180(800fsb) CPU which has served me well for the last couple of years. However i am in the process of upgrading to a Q6600(1066mhz FSB) and im not sure what DDR3 ram to get. Im not so worried about the performance increse the mem is going to give me over my old ram but it is essential i can use the DDR3 ram for my next upgrade to i5 or i7 in a couple of years or so. My mobo is a P5KC and has 2 DDR3 slots, I can use upto 1333mhz DDR ram. SHould the speed of the ram match or be better then the FSB of the CPU.

Thanks in advance.

MagicBoy · 8 Feb 2010 at 11:03

There's about a 1% difference. Pointless upgrade - spend the money on something more useful like a faster HDD or graphics card.

big.rich1976 · 8 Feb 2010 at 11:24

Surely if i leave this old ram in tho it will cause a bottleneck. As i mentioned in my orig post im not bothered about how much performance i will see re the ram but i will be overclocking the Q6600 and dont want to be held back.

MagicBoy · 8 Feb 2010 at 11:44

Depends. If you have two DIMMs installed then it's running in dual channel mode. Therefore you've effectively got 1333MHz (2*667MHz) of RAM bandwidth which is more than the FSB of the Q6600.

Admiral Huddy · 8 Feb 2010 at 11:51

I have the same mobo and once tried DDR3 memory. Made no difference at all. plus the DDR3 controller is a bit flaky to say the least. Bear in mind too that because the memory controller for C2D is located on the mobo, the DDR3 memory requires more power. The current range of DDR3 modules for i3/i5/i7 where the controller is located on the CPU require less power and will not work on your S775 combo. Likewise, if you can get some higher voltage DDR3 modules, don't expect these to work later on an i3/i5/i7 system because these are different.

Your bet bit is get hold of some PC2-8500 and beef up your exsisting overclock.

gurusan · 8 Feb 2010 at 11:59

MagicBoy said:
Depends. If you have two DIMMs installed then it's running in dual channel mode. Therefore you've effectively got 1333MHz (2*667MHz) of RAM bandwidth which is more than the FSB of the Q6600.

Nope you're getting confused there

667MHz ram in dual channel is still just 667MHz

Admiral Huddy · 8 Feb 2010 at 12:01

gurusan said:
Nope you're getting confused there 667MHz ram in dual channel is still just 667MHz

correct ..

MagicBoy · 8 Feb 2010 at 12:01

Yeah. But it's twice as wide, therefore bandwidth is doubled.

gurusan · 8 Feb 2010 at 12:03

MagicBoy said:
Yeah. But it's twice as wide, therefore bandwidth is doubled.

In theory yes, but if you take a look at an everest bandwidth comparison or something you'll find a only a few % difference on the 775 platform

Admiral Huddy · 8 Feb 2010 at 12:04

MagicBoy said:
Yeah. But it's twice as wide, therefore bandwidth is doubled.

But you were confusing this with the frequency of the RAM, They are not the same thing.

Understanding, Choosing and overclocking DDR2.

big.rich1976 · 8 Feb 2010 at 15:06

Thanks for the info guys, will take a look at some DDR2 me thinks.

reflux · 8 Feb 2010 at 15:08

yeah DDR3 is really only worth it if you have to have it.

big.rich1976 · 8 Feb 2010 at 16:17

I was only going to try and get DDR3 ram purely for compatibilty later on when i go to i5 or i7

Admiral Huddy · 8 Feb 2010 at 16:18

big.rich1976 said:
I was only going to try and get DDR3 ram purely for compatibilty later on when i go to i5 or i7

Not a good idea.. See post #5 above.

big.rich1976 · 8 Feb 2010 at 16:23

yeah i saw, will just get some compatible DDR2. God this mem lark is so confusing nowadays.!!!

Admiral Huddy · 8 Feb 2010 at 16:38

It's certianly not as clear cut as it once was but progress comes with complexity..

big.rich1976 · 8 Feb 2010 at 17:24

yeah bring back the PC100 and PC133 days!

Uriel · 8 Feb 2010 at 17:30

Save your DDR2 - the prices are going up. In about 1-2 years I wouldn't be surprised to see 4GB branded DDR2 selling for the same price as 8GB DDR3.