View Full Version : Trouble getting a high FBS OC out of my DFI nf4U

04-05-05, 11:01 AM
Now that I figured out how to control CPU voltage on the DFI nf4U I've been able to get a decent OC, 12*220=2640 @ 1.7v, RAM(SPD) 1:1 2.7v, LDT 1.2v, HTT x5 1.6v(nf4) is what I'm currently running rock solid.

Here's the deal.....I can't seem to get operational going for a higher FBS, lower multi OC :(
for example: 11*236=2600 1.7v, RAM(SPD) 1:1 2.8v, LDT 1.3v, HTT x4 1.5v results in a hang on boot or if it boots, no USB function in XP.
I also tried afew other combos like: 10*260=2600 1.75v, RAM(SPD) 1:1 3.0v, LDT 1.3v, HTT x4 1.6v again hangs on boot, usually after APCI.
So, what gives? Seems strange that the CPU fails at a lower speed, because of an increased FBS(this isn't typical behavior). I'm thinking its either 1. USB or periph ports are over speeding(not locked), 2. the PCI-e bus is not locking or 3. the HTT multiplier is not dropping as I set it.

What do you think? Anything jumping out at you? Anyone know what "LDT" is or does?

The full specs are in my sig

04-06-05, 11:23 AM
Try to keep the HTT under 1000. I doubt even the DFI can handle anything higher

04-06-05, 11:55 AM
Yea try lowering your HTT to 3, and drop your memory ratio.

04-06-05, 12:04 PM
PaiN, if you can't get it figured out you might go ask Sierra over on abxzone. the man is a guru. :)

BTW, as you prolly already know, HTT of 4x is fine at less than 250FSB.

04-08-05, 03:34 PM
sorry I haen't been watching this thread.....
I have been working hard to get this resolved and figure out what was going on. To boil it down, my current RAM doesn't like to run up or in a-sync with this CPU......once I had the bios down I was able to divide out the RAM and get a solid 300x9 :cool:

If you're interested in the ugly details here's some links, the second link has CPU-z screens... :


04-09-05, 04:43 PM
There's a few things i don't understand about amd64 overclocking.

1. Can someone please explain how the HTT x# setting interacts with overclocking. and how it adds up to 1000mhz.

2. Isn't a bad idea to have the memory out of sync with the processor fsb? or does this act different because of how the memory controller is built into the cpu?

04-09-05, 05:42 PM
Take your FSB (200) x the default multiplyer (5x) and that gives you the HTT.

If you run a 250fsb, you would want to decrease your multiplyer to 4x

04-11-05, 02:09 AM
On a A64 CPU running the memory out of sync on a nforce3 dose'nt hurt the speed of it like it does on a nforce2 running a barton cpu out of sync.