Ram not working at 800MHZ? only 333.9MHZ?

Matrix · 19 Nov 2006 at 18:57

I've just set up a new system and i've ran Cpu-z and seen my ram is at 339.5MHZ instead of 80oMHZ.

I have a E6600, Asus P5W DH and my ram is Geil2gb PC6400c4 800MHZ ultra low latency DDR2 Dual channel

I'm hoping someone can help me out please?

Thanks

Jokester · 19 Nov 2006 at 19:00

It's because of the RAM divider it's on. You'll need to go into the BIOS and change it's speed from 667MHz to one up assuming it doesn't exceed 800MHz. You might also need to double check the RAM voltage is set to the manufacturers recommended setting and not rely on the board's default.

Jokester

harris1986 · 19 Nov 2006 at 19:08

check ram volts are at their stock!

snowdog · 19 Nov 2006 at 19:43

!st of all you need to double the reading in cpu-z ( ie. 800mhz is actually 400 in cpu-z)

You need a divider in bios to let ram run faster as your cpu...

thefishdude · 19 Nov 2006 at 21:06

you have to double that numbers as its ddr2 . sooo your ram is runing at 680. if ytoiu want it to run at 80omhz or 2:3 in memory section of bios. also you may need to up the voltages to the ram depending on what brand you got. also you will need to anually change the ram timings to 4-4-4-12

harris1986 · 19 Nov 2006 at 22:17

no you double it because it's giving the speeds per stick! it's not running 680mhz per stick lol, either in bios it's not set to run 1:1 or his volts are too low for the ram which is a common problem with the geil stuff!

thefishdude · 19 Nov 2006 at 22:29

what you mean it giving speeds per stick ??? soo if i had one stick only you saying it would wonly be runing at 340mhz ??????? or do you have to have 2 sticks of ddr2 ? and what if you had 4 sticks ???

Jokester · 19 Nov 2006 at 22:34

No the RAM is running on a 4:5 divider so that on a 266MHz FSB the actual RAM is running 333MHz (double data rate of 667MHz). To get it to run at 800MHz on a P5W all you need to do is manually set the speed to 800 (2:3 divider), assuming the voltage and timings aren't too tight. It will appear in the BIOS as 667MHz as the BIOS gives you the actual double data rate the RAM is running at no the divider.

Jokester

Matrix · 20 Nov 2006 at 11:30

Jokester said:
It's because of the RAM divider it's on. You'll need to go into the BIOS and change it's speed from 667MHz to one up assuming it doesn't exceed 800MHz. You might also need to double check the RAM voltage is set to the manufacturers recommended setting and not rely on the board's default.

Jokester

Thanks for the info i'm not sure where abouts in the BIOS i need to look i've be through and i couldn't see anything for memory?

Thanks

wjfcomputers · 20 Nov 2006 at 13:42

harris1986 said:
no you double it because it's giving the speeds per stick! it's not running 680mhz per stick lol, either in bios it's not set to run 1:1 or his volts are too low for the ram which is a common problem with the geil stuff!

No. You do not double it because there are two sticks. Why post if you don't know what you are talking about?

It's doubled simply because it's DDR.

gash2024 · 21 Nov 2006 at 08:57

what there trying to say is
stick 1 400MHz
stick 2 400MHz

=800MHz

Set your timings and voltage manually or you will have problems and if you intend to run 800 MHz up the FSB voltage by 0.1V and dont ever rely on the boards defaults or auto settings i did once and i will never again.

pastymuncher · 21 Nov 2006 at 11:06

Don't be so bloody stupid! Stick 1@400 and stick 2@400 does'nt equal 800mhz.

Just listen to what Jokester says and you will be fine.

Matrix · 21 Nov 2006 at 15:21

Could someone please tel lme then where to go in the bios cause i just can't see where i need to go to change the settings?

Thanks.

pastymuncher · 21 Nov 2006 at 16:37

Somewhere in your bios you should have an entry called DRAM settings, or similar. It should be in there. Thats where mine is anyway.

gash2024 · 21 Nov 2006 at 17:00

pastymuncher said:
Don't be so bloody stupid! Stick 1@400 and stick 2@400 does'nt equal 800mhz.

Just listen to what Jokester says and you will be fine.

err spanner if stick 1 is 400 mhz and stick 2 is 400mhz then suprisingly your going to finish up with a total of 800 mhz :rolleyes:

Matrix if you cant find your bios menu press Ctrl F1 (might be Ctrl 1 cant remember)

FreeStream · 21 Nov 2006 at 17:29

gash2024 said:
err spanner if stick 1 is 400 mhz and stick 2 is 400mhz then suprisingly your going to finish up with a total of 800 mhz

Matrix if you cant find your bios menu press Ctrl F1 (might be Ctrl 1 cant remember)

No, he is quite right.

One 400mhz stick and another 400mhz doesn't = 800mhz. They are still running at 400mhz.

DDR = Double Data Rate, this is double what SDR would be (Single data rate).

So if a stick is at 400mhz, and its DDR, the mhz is doubled because its doing twice the work per clock cycle (800mhz).

Thats it.

gash2024 · 21 Nov 2006 at 17:49

o.k u got me but you know what i meant as we know its DDR 2 dual channel

FreeStream · 21 Nov 2006 at 17:55

gash2024 said:
o.k u got me but you know what i meant as we know its DDR 2 dual channel

Just version 2 of DDR, like DDR is version one.

DDR3 = 3rd version of DDR
DDR4 = 4th...

etc

Dual channel means that the mem controller can access both sticks at the same time. Which in theory doubles bandwidth.

pastymuncher · 21 Nov 2006 at 19:17

Thank you Concorde.

Has anybody actually got the same mobo (Asus P5W) as Matrix so that he knows what to change?

Matrix · 23 Nov 2006 at 09:40

pastymuncher said:
Thank you Concorde.

Has anybody actually got the same mobo (Asus P5W) as Matrix so that he knows what to change?

Yep i'm still not sure what i'm changing here guys