DDR2-900 memory overclocking issues. What am I doing wrong here???

[OCZSpeedJunky]

Ok, I am confuzzled here. I know that obviously with DDR RAM, it was simple, take the FSB, for example 200mhz, and double this to get you RAM speed of DDR 400, assuming it is running 1:1 with the CPU. OK, so now then with DDR2 RAM.
Correct me if I am wrong, but isn't it basically the same thing, taking the FSB, and multiplying it?? so, for DDR2 RAM, we take the FSB, as example 200mhz, and multiply that by 4, to get say DDR2 800mhz RAM correct?? Or am I doing this wrong??
Reason for asking, is I am playing around with my Asus Crosshair mobo, which I have installed OCZ DDR2-900 Platinum EPP RAM on. So, naturally by default it takes DDR2-800 PC2-6400 RAM. So, I drop the CPU multi ti 11X, as to not clock the CPU much right now. Then, I up the FSB too 225, which when multiplied by 4 should put my DDR2 RAM at 900mhz correct?? I did this, but it says my RAM is running at 825mhz according too cpu-z. Am I doing something wrong here??
Someone please help me out, 'cuz I'm a bit confuzzled here. Since DDR2 RAM takes data in chunks of 4, to get the proper speed isn't the FSB multiplied by 4 then to get the effective DDR2 speed??
Thanks for the input ahead of time....I be thinking I need it at the moment lol

OCZ

[OCZSpeedJunky]

OCZ2N9002GK DDR2-900 PC-7200 900mhz 2 x 1GB kit - Does anyone have the slightest clue what chips they are using on these modules?? I would like to know, but don't exactly feel like popping off mt heat spreaders to find out. Is there another way I can find out what chips they are using, so I know whether I want to stick with these or not. Thanks

OCZ

[clokwerk oranje]

Ok, I am confuzzled here. I know that obviously with DDR RAM, it was simple, take the FSB, for example 200mhz, and double this to get you RAM speed of DDR 400, assuming it is running 1:1 with the CPU. OK, so now then with DDR2 RAM.
Correct me if I am wrong, but isn't it basically the same thing, taking the FSB, and multiplying it?? so, for DDR2 RAM, we take the FSB, as example 200mhz, and multiply that by 4, to get say DDR2 800mhz RAM correct?? Or am I doing this wrong??
Reason for asking, is I am playing around with my Asus Crosshair mobo, which I have installed OCZ DDR2-900 Platinum EPP RAM on. So, naturally by default it takes DDR2-800 PC2-6400 RAM. So, I drop the CPU multi ti 11X, as to not clock the CPU much right now. Then, I up the FSB too 225, which when multiplied by 4 should put my DDR2 RAM at 900mhz correct?? I did this, but it says my RAM is running at 825mhz according too cpu-z. Am I doing something wrong here??
Someone please help me out, 'cuz I'm a bit confuzzled here. Since DDR2 RAM takes data in chunks of 4, to get the proper speed isn't the FSB multiplied by 4 then to get the effective DDR2 speed??
Thanks for the input ahead of time....I be thinking I need it at the moment lol

OCZ

it works differently for calculating DDR2 Freq on AM2... you have to look at your multi, in this case x11 multi will give you mem divider of /6...

ergo, FSB 225MHz x 11 = 2475MHz for the CPU...
DDR2 Freq 2475 / 6 = 412.5MHz x 2 = 825MHz...

if you've had kept multi at x12, your mem divider stays at /6... you'll get;
FSB 225MHz x 12 = 2700MHz (CPU)
DDR2 Freq 2700 / 6 = 450MHz x 2 = 900MHz...

Breakdown of Multi/Dividers for AM2
Multi x10 - Divider /5
Multi x11 - Divider /6
Multi x12 - Divider /6
Multi x13 - Divider /7
Multi x14 - Divider /7

[3oh6]

Breakdown of Multi/Dividers for AM2
Multi x10 - Divider /5
Multi x11 - Divider /6
Multi x12 - Divider /6
Multi x13 - Divider /7
Multi x14 - Divider /7

that list above is just when on the 800 divider...here is a link to a chart with all the dividers:

http://www.xtremesystems.org/forums/...ht=am2+divider

as for what ICs are on the 7200 EPPs...it depends. mine are D9GKX, others have D9GMH on theirs so there is only one way to find out but its pretty safe to say it is one of those two ICs. HTH

[aspevacek]

Mine are the D9GMH chips and seem to be decent to say the least

I had a Crosshair for about a week, I dont know if it is just my being used to DFI bios layout that I did not give the board a shot, or the fact I got rid of a nice set of Patriot 7200's over it. But either way I did not care for the crosshair even with all its fancy LEDs.

[OCZSpeedJunky]

it works differently for calculating DDR2 Freq on AM2... you have to look at your multi, in this case x11 multi will give you mem divider of /6...

ergo, FSB 225MHz x 11 = 2475MHz for the CPU...
DDR2 Freq 2475 / 6 = 412.5MHz x 2 = 825MHz...

if you've had kept multi at x12, your mem divider stays at /6... you'll get;
FSB 225MHz x 12 = 2700MHz (CPU)
DDR2 Freq 2700 / 6 = 450MHz x 2 = 900MHz...

Breakdown of Multi/Dividers for AM2
Multi x10 - Divider /5
Multi x11 - Divider /6
Multi x12 - Divider /6
Multi x13 - Divider /7
Multi x14 - Divider /7

Yea, I was kinda thinking that was how it worked, Thanks for clarifying that. I had purposely stayed away from CPU's like the X2 4200+/4400+/5000+ because of the odd number multi which causes issues when it comes to the mem divisor. I read that somewhere. Anyway, I will just change the CPU multi back to x 12. I only dropped it to x 11 because I was thinking along the old DDR o'clocking, "drop the multi, up the FSB to increase the RAM speed". I see how it is supposed to work now. I know the mem divisor is 6, just didn't realize I had to always use that to calculate the RAM speed with DDR2. So, I'll go make a few changes and get it back up too speed. As soon as I here back from OCZ on my RAM. For some odd reason, whenever I enable the EPP and let the mobo do the auto max overclock, I get a boat load of errors, BSOD's, and the system will randomly crash. One of the guys at OCZ thinks my chips may have been programmed with the incorrect SPD, so I may need to exchange them.
But anyway, thanks for clarifying the memory divisor. Didn't realize I always needed to use it to calculate the speed. And thanks for the divider list. Much appreciated. I'll give ya'll a hollar this weekend after I drop the new X2 4800+ in and tweak that for a bit. Still got the single core 3800+ in it at the moment. Thanks guys.

OCZ

[OCZSpeedJunky]

as for what ICs are on the 7200 EPPs...it depends. mine are D9GKX, others have D9GMH on theirs so there is only one way to find out but its pretty safe to say it is one of those two ICs. HTH

And as for the chips they are using on the EPP 900's, I seen somewhere that OCZ never uses the Micron chips, unless I misread and they were referring to a specific set of modules that they were referring too. I'll do some digging and see what else I can find out about the IC's. 'Cuz I won't go through the hassle of popping the heatspreaders to find out. I'll post more info on that when I get it. Thanks guys.

OCZ

[RyderOCZ]

7200 EPP Can have Micron on them.

[OCZSpeedJunky]

7200 EPP Can have Micron on them.

Cool deal Ryder. I was wondering 'cuz I know my DDR400's had TCC5 chips if I remember right, and now days everyone wants the Micron D9 chips. I just recall seeing a thread yesterday about someone wondering about OCZ using D9's on another set, don't remember which ones though. Appreciate the info. Once I get the new CPU dropped in I'll have too see how these puppies clock. Fun fun.

[myrddin669]

with vdimm= ca. 2,6V
P5W64 WS PRO



no doubt very interesting memory

[OCZSpeedJunky]

with vdimm= ca. 2,6V
P5W64 WS PRO



no doubt very interesting memory

Wow, nice speeds and timings bud. I haven't had a chance yet to push this set, but I will this weekend. My X2 4800+ should be here tomorrow, and I'm waiting on that. Maybe I'll try pushing this 3800+ Orleans single core before I yank it out.
Just out of curiousity, what would you think would be the max I might wanna push this 3800+ CPU too as far as max voltage?? Stock it's reading 1.36volts(probably 1.35v stock version), and when I let it auto overclock in the BIOS, I set it at 1.55v. So whatcha think, 1.65 or 1.7v probably for a max volt to push it?? My board will go all the way up too 1.85v, and the RAM voltages will go up too 3.425v. So I got plenty of room. Just don't wanna cook the 3800+ Orleans 'cuz I plan on getting rid of it. Let me know whatcha think. And I'll see what I can maybe get out of it before I yank it out this weekend.

OCZ