memory timings on the PII X4 940

[imported_Redmist]

this is kinda confusing for me to ask the right way, so plz bare with me and try to understand what im asking here.


I'm building a new system soon and Im looking to get one of the new Phenom II cpus, either the X4 940 or the X3 720.

Right now Im gaming on an AMD X2 6000+ with 4 gigs of DDR2 800mhz. since the cpus multiplier is 15 and the memory divider is 7.5 my ram is running at 375mhz (x2) instead of the advertised 400mhz, I know I can make this 400mhz by upping my fsb to 214 but this 560 nforce chipset runs pretty hot when OC'd.

so say if i get new ram, that runs at 1066 for a am2+ mobo to go with the PII X4 940 cpu, will this ram only run at the same speeds because of the odd 15/2 = 7.5 memory divider or how does everything calculate differently?
what settings do i need to have to get the ram to at 1066 with the cpu being on stock 3.0?

 

[richierich1212]

Well if you want the Ram @ 1066 with the CPU on stock, you just go to the BIOS settings and select DDR 2 1066. That's it. You don't have to worry about dividers at the stock speed.

 

[imported_Redmist]

yah but doesnt the odd multiplier set things off? isnt the formula cpu freq divided by memory divider?

in bios my memory reads 800mhz but in cpu-z its 375mhz because of the x15 mutliplier is really 7.5 and its rounded up to 8, so its 3000 divided by 8 which is 375... is this formula changed?

 

[Flipped Gazelle]

Originally posted by: richierich1212
Well if you want the Ram @ 1066 with the CPU on stock, you just go to the BIOS settings and select DDR 2 1066. That's it. You don't have to worry about dividers at the stock speed.

This.

If you populate all 4 RAM slots, it may default to DDR2-800. In that case, you need to set the RAM to 1066 in the BIOS. Sometimes that doesn't work, and you'll have to run it at 800.

 

[Flipped Gazelle]

Originally posted by: Redmist
yah but doesnt the odd multiplier set things off? isnt the formula cpu freq divided by memory divider?

in bios my memory reads 800mhz but in cpu-z its 375mhz because of the x15 mutliplier is really 7.5 and its rounded up to 8, so its 3000 divided by 8 which is 375... is this formula changed?

Nope, the RAM speed for Phenoms is computed differently than for X2. It's very much like Core2.

 

[imported_Redmist]

oh sweet thanks guys, i was worried id be stuck with running 1066 memory at 750

 

[TotalLamer]

Theoretically a Phenom II won't run 4 sticks of DDR2 at 1066, but I've got 8GB in my board and have it manually set to 1066 @ 2.1V (rated 2.0-2.1V) no problem in the BIOS.

 

[heyheybooboo]

I think it would be worth recycling your DDR2 800MHz if you are not going to use it in another system. Will the NF560 do the PhII's ??

 

[imported_Redmist]

Originally posted by: heyheybooboo
I think it would be worth recycling your DDR2 800MHz if you are not going to use it in another system. Will the NF560 do the PhII's ??

nah this mobo is only am2, I remember seeing on the support site saying it was AM2+ ready and there was a hidden bios update, you had to send an email request for the bios but it appears like its gone now.
http://global.msi.com.tw/index...1244&maincat_no=1#menu

I'm just going to use the left over parts for a second system. maybe i can get my wife into playing some age of conan with me

 

[Keysplayr]

Are there any probs running 2x2GB sticks at 1066? Or is it just when all slots are populated?

 

[Flipped Gazelle]

Originally posted by: keysplayr2003
Are there any probs running 2x2GB sticks at 1066? Or is it just when all slots are populated?

Just when all 4 slots are populated.