cpu overclock and memory divider question!

[ta8689]

Ok... i have my cpu at 2.5 ghz.. and its unstable unless i put memory on auto. But then it puts it on 2T and ddr266... its ddr500 memory.. WHat do i do??

 

[BassBomb]

did u lower HTT mutliplier?

you should be able to OC ur HTT == Memory.. not needing a divider, since that ram is rated high

 

[ta8689]

what should the htt multi be? i have it at 3

 

[kmrivers]

250x4 sounds about right

 

[ta8689]

what do you mean 250x4? its at 266.... i thought it should be higher

 

[kmrivers]

250HTTx4, 1:1 HTT and mem, 250x9 = 2.25ghz

 

[ta8689]

???? ok my cpu is running 2.50. Im confused. I have an a8n-sli premium mobo,may be diff then yours..???

 

[kmrivers]

i dont have a 939 box. just going based on what i know.

if your cpu is running at 2.5ghz then you have you HTT at about 280 or so. Which would mean you are overclocking your memory unless you are using a divider. To oc with your memory running at spec here is what you do.

HTT: 250
HTT multi: x4
Mem: 1:1(250) i dont know that it is called in your bios

so: 250x9 = 2.25ghz
which may need a vcore increase i dont know.

 

[ta8689]

well i have vcore at 1.4, i have it set as 175x9 rite now. and how do i raise htt? i can raise bulti, but i only have options like ddr266, 333,400,433,500,etc.

 

[Giantsfan24]

the ddr266etc are part of the mem divider. Lets say you ram only goes to 210mhz(it seams like your would go higher but you need to find your max mem speed). Anyway, if you are running 2.5GHZ with a 9 multiplyer, then you HTT(fsb) should be about 277. You obviously cant run that 1:1 since you mem cant go that higher so you drop the mem down to ddr266 or ddr333 and that way, when you oc the cpu, it will run the ram near your max mem frequency.

 

[5t3v0]

As you have DDR500 memory you might well be able to run 1:1 with some tweaking and luck. I also run at 9x280 and have DDR500 but I cant run 1:1 so use the 166 or DDR333 (5:6) divider to give 229MHz on the memory. Running the memory lower than stock might allow you to tighten up some of the timings.

HTT is the cpu frequency - this can be changed in 1MHz increments. You say you have this set at 275 just now.
The memory frequency is the one with options like 266, 333, 400, etc. It is not a fixed setting. It sets the memory speed at a ratio of the cpu which is why its called a divider. At 200 HTT a 333 divider will set the memory at 333. When you start raising the HTT, the divider causes the memory frequency to increase proportioanlly. Use A64MemFreq1.1 to guide you on setting this.
HT or LDT is the bus between the cpu & memory. Its frequency is calculated HTT x HT multiplier x2. It should always be below 2000. Your HT multi is spot on at x3, this gives 3 x 275 x 2 = 1650

 

[ta8689]

Hey thanks, i think i get it now. Sorry it took me a while to get back.. i reformatted, it seems to run more stably with the dual core now. And yesterday was my birthday.. so i was a little busy 🙂

 

[5t3v0]

You're welcome. Happy birthday!

 

[chocoruacal]

Originally posted by: ta8689
Hey thanks, i think i get it now. Sorry it took me a while to get back.. i reformatted, it seems to run more stably with the dual core now.

What do you mean? Either its stable or it isnt. Download Stress Prime 2004 and install it into two separate folders. Then run dual instances of Prime 95, one for each CPU. The AN8 boards are notorious for not liking 1T timings at 200+ MHZ HTT, so don't be too let down if you have to run 2T. Personally I'd run a divider and so that I could use 1T and tighter memory timings, which would most likely be faster anyway.

 

[ta8689]

Yeah thats what im doing. And its stable with a divider and 1t at 2.48 ghz. I guess im happy with this for now. There were problems with my o/s and it needed to be reformatted. It wasnt cpu instability. I cant really say what it was, but its gone now. Maybe it just wanted to have everything installed again with the dual core. Thanks.