How to get my DDR2 memory up to 1000MHz?

Naujoks

Distinguished
Mar 29, 2006
190
0
18,680
I just myself these:
OCZ XTC Platinum OCZ2P10002G (2x2gb)

My mobo is the Abit AB9, with an E6850 CPU, running at 3.06GHz.
When I switched it on, the memory was recognised, and is running stable, but it's shown running at 850Mhz in the BIOS (and under CPUz).

I'd like to get it up to 1000MHz though, but don't know how, so I would be very grateful for any help!
 

blackwidow_rsa

Distinguished
Aug 16, 2007
846
0
18,990
Setting the memory faster than the fsb will make no difference. The cpu won't be able to use the extra bandwidth.
In dual channel your RAM would technically be running at 1700mhz (850 x 2).
 

Naujoks

Distinguished
Mar 29, 2006
190
0
18,680
Did I fundamentally misunderstand this whole issue then?
The E6850 the has a 333MHz FSB (1,333MHz effectively), so shouldn't that match a memory speed of 1000MHz or even 1066MHz? Otherwise I wouldn't need 800MHz RAM, or even just 667MHz, or would I?

I'm very confused now. Where is the bottleneck then? If I want to use my RAM at it's best speed, which CPU would I need to get?
 

br3nd064

Distinguished
Aug 20, 2008
807
0
18,990
No, it should match the speed of 1/2 of the effective fsb.

For example: I have a e8500 oc'd to 3.8ghz. 1/2 of the fsb is 800, so I'm using DDR2 800mhz ram... There is no bottleneck because the FSB and RAM are synced 1:1.

If you want to use that cpu at the ram's best speed, you would need a motherboard that is known to support a 2000mhz fsb. You would then lower the CPU multiplier, raise the voltage, and raise the normal fsb to 500mhz.

A warning though: the chip *might* support the high fsb, but there aren't many motherboards that are stable around that speed.
 

Naujoks

Distinguished
Mar 29, 2006
190
0
18,680
So, at present my motherboard, which is 1033MHz FSB doesn't even come close to the speed of my RAM, barely half the speed?!
The question is then a more general one, which is why motherboards lag behind the other components so much.
 

br3nd064

Distinguished
Aug 20, 2008
807
0
18,990
That's right, unfortunately. That's why it doesn't make any sense for people to be switching to DDR3 @ 1600mhz.

It's not really the motherboards that lag behind, it's mostly the cpu's. Although, there are cpu's that can reach >500mhz fsb, it's not really worth it because it's putting unnecessary stress on all the other components. You will see very little performance increase between running a low multiplier, but high fsb, and medium multiplier, but lower fsb.
 

cd14

Distinguished
Mar 29, 2006
226
0
18,680


If you want to run 1066 mhz ram at 333 FSB, you will need a multiplier of 3.2. This will get the ram to 1066 with a FSB/RAM ratio of 5:8.