am2 ddr2 dividers

[knacky]

[MusicIsMyLife]

Great work.

This is what I searched for.

[knacky]

weird interesting findings
in 3000+ am2 orleans cpu multipliers 6x and 7x don't work
9x multipliers applied
667 memory divider don't work with full cpu multipliers
400 memory divider don't work with half cpu dividers
when set board don't post or windows don't boot
no matter if i rise the voltage or not it simply don't work

[dz_jad]

I'm confused...I havent overclocked any 64's yet, but I've got one in the mail, what would this be used for?

[knacky]

table shows the real memory clock in am2 oc

[dz_jad]

so if you bump the HTT and multiplier and such, then you'll end up with this memory clock? thanks

[akijikan]

mfn' sweet, thx

[arisythila]

It is very wierd how this works.

~Mike

[3oh6]

thanx for the chart, i was about to sit down and put one together myself...now i don't have to

[jpennstar]

would someone help me understand what the >/# means?

I'm trying to OC my 3000+

[3oh6]

would someone help me understand what the >/# means?

I'm trying to OC my 3000+

that is the divider that the memory frequency is derived from. you divide your CPU frequency by this number for memory frequency. for example...

if your CPU multiplier is set to 10
and your HTT is set to 200
and your memory is on the 667 divider which = /6

then this is how the math works out:
2000*10 = 2000 / 6 = 333.3 (DDR667)

make sense?

[dz_jad]

so it tells you what to set it at, or is it just showing, if you have this HTT and multiplier, then the mem divider will be this...?

[3oh6]

its just a chart showing what the DDR frequency is, at the given HTTs and memory dividers provided...quite handy.

[ozzimark]

It is very wierd how this works.

~Mike

exactly the same as the older K8's, just with different memory ratios

[jpennstar]

OH... well that makes more sense and is helpful.

Cuz I have an AM2 3000+ now at 2.4 (268HT, 4X) and I'd like to get to 2.8. I have Corsair XMS2 DDR2 800 5.5.5.18 2T. I've tried just about everything, it seems, to get it there. I reached 2.6ghz but that wasn't nearly as stable as the 2.4ghz setting.

I have Swiftech H20 on it so I know it isn't the temps and I've increased the volts on everything and still no go so I am sure its something to do with the memory and memory timings.

I have a CPU multi of 9, so if I set my HT to 300, my DDR2 divider to 533 /7 my memory will be running at 771mhz which would be within specs.

[afireinside]

Thanks for the tables! I've been to lazy to write them down and I hate going through multis and mem settings to find the one I need.

[jpennstar]

Basically

(HTT X CPUmulti) / RAM Divider = RAM mhz & 2X equal effective mhz

Why does the chart have specific HTT numbers, are those the only ones the DDR2 will work with or are they just random steppings to show the progressions?

For example. Could I use 310HTT which gives me 801. effective. ???

[3oh6]

Why does the chart have specific HTT numbers, are those the only ones the DDR2 will work with or are they just random steppings to show the progressions?

yup, just random stepping to show the memory frequency progression as it scales. like AFI said, thanx for giving us the means to be lazy

[jpennstar]

MAN I tried /9 and /7 with different latency combinations and volting the hell out of my computer and nothing......... No a happy comp I guess.

2.4ghz is as far as I can go. Don't get me wrong its definently a snappy comp but I'd still like 2.8.

HTT - 267
HTTx - 4
HTTv - 1.3
CPUm - 9
CPUv - 1.45
RAM - /7 (533)
RAMv - 2.1
RAM - 4.5.4.12 2T

Hey getting a 3800+ for 93 bucks is cool!

[jrw]

Excellent!

[tzitzos]

excellent

thx dude

[Warship]

"HTT - 267
HTTx - 4
HTTv - 1.3
CPUm - 9
CPUv - 1.45
RAM - /7 (533)
RAMv - 2.1
RAM - 4.5.4.12 2T"

Drop your HTT-multi to x3 and raise that HTT-freq.

[OCZSpeedJunky]

A little more info for guys working with the new AM2 CPU's. Here is the default/stock Memory Divisors, CPU Multipliers, & L2 Cache listed per chip for all the Athlon64 currently out:

Single Core Orleans (all 512KB L2 Cache)
1.8ghz, 3000+ CPU Multi x 9 / Memory Divisor 5
2.0ghz, 3200+ CPU Multi x 10 / Memory Divisor 5
2.2ghz, 3500+ CPU Mutli x 11 / Memory Divisor 6
2.4ghz, 3800+ CPU Multi x 12 / Memory Divisor 6

Dual Core X2 Windsor
2.0ghz, X2 3800+ CPU Multi x 10 / Memory Divisor 5 *L2 Cache - 512KB x 2
2.0ghz, X2 4000+ CPU Multi x 10 / Memory Divisor 5 *L2 Cache - 1MB x 2
2.2ghz, X2 4200+ CPU Multi x 11 / Memory Divisor 6 *L2 Cache - 512KB x 2
2.2ghz, X2 4400+ CPU Multi x 11 / Memory Divisor 6 *L2 Cache - 1MB x 2
2.4ghz, X2 4600+ CPU Multi x 12 / Memory Divisor 6 *L2 Cache - 512KB x 2
2.4ghz, X2 4800+ CPU Multi x 12 / Memory Divisor 6 *L2 Cache - 1MB x 2
2.6ghz, X2 5000+ CPU Multi x 13 / Memory Divisor 7 *L2 Cache - 512KB x 2
2.6ghz, X2 5200+ CPU Multi x 13 / Memory Divisor 7 *L2 Cache - 1MB x 2

Dual Core FX-62 Windsor
2.8ghz, CPU Multi Unlocked up too x 25 / Memory Divisor 7 *L2 Cache - 1MB x 2

Generally, if you are running the CPU at default stock multi/speed, take the default CPU clock speed, and simply divide it by the Memory Divisor, that will give you the stock speed when using the DDR2-800mhz divider. Example, take the Orleans 3000+ for instance, which default is at 1800mhz(1.8ghz) stock. To find the speed at which your DDR2-800+ will be running at, it's as follows:

example:
200mhz FSB x 9 CPU multi = 1800mhz effective CPU clock speed
1800mhz / 5 Memory Divisor = 360mhz
360mhz X 2 = 720mhz *what DDR2-800/900/1000/1066/1100+ will run at stock w/ a 3000+ CPU at stock/default FSB/CPU multi

All the CPU's which have a default "odd numbered" multiplier will run DDR2-800 below stock/spec speeds. That includes anything that runs above 800mhz also, such as DDR2-900/1000/1066/1100, etc. All the CPU's with "even numbered" multpliers will run at DDR2-800 stock. It's an annoying issue with all the chips that come with a "odd numbered" multi's. So you MUST overclock the "odd multi" CPU's to get your DDR2-800/900/etc. to stock speed. As far as other speeds, 667mhz, 533mhz, knacky's tables above are a great idea to use. Nice work knacky. :thumbsup:
Hope this helps a few people understand more along with knacky's tables above on how the new AM2 Memory Divisors work.

OCZ

[GFreeman]

Righto, imagine that I have a 4800+ Brisbane cpu.. which come with a half multi (12,5).. not sure if the same formula goes for that too?

So let's say i'm using the DDR800 devider.

We have 200htt x 12,5 (cpu multiplier) = 2500 Mhz
2500 /5 = 500 Mhz x 2 = 1000Mhz on my modules... correct?

[ozzimark]

ceiling ( 12.5 / (2/1) ) = ceiling ( 6.25 ) = cpu/7