FSB Help: Crosshair V Formula

[I.M.O.G.]

I need input for getting a higher FSB on this board. Using a FX-8120 currently, same issue on FX-6100.

I can't raise FSB higher than 263MHz without immediately crashing, what should I try in order to hit 270FSB, 280FSB, or 290FSB?

In testing, these were my settings. Let me know if you have any suggestions or questions...

CPU Multi: 17X
Vcore: 1.85V (LN2)
CPU-NB Volts: 1.55V
CPU-NB Multi: 9X or 10X
HT Link Multi: 9X or 10X
Ram Voltage: 1.8V (11-11-11-40 2T)

So at 263MHz FSB for example, I'd be 2630MHz on CPU-NB and HTLink, and 4471MHz on CPU frequency. I've tried memory dividers of 1066 and 1333 - my RAM is rated for 1600MHz, so at 1066 I would only be hitting 1400MHz on the RAM, and at 1333 I would only be hitting 1750MHz.

The CPU can do 31.5 X 257MHz, so core frequency and temps aren't holding me back - I just can't figure out why I have this FSB limitation. Any ideas?

 

[Woomack]

I have similar issue on UD5 with FX8120. I mean higher FSB = lower memory clock or it won't boot at all. I can set 300MHz+ FSB with 1600 memory but I cant set 250MHz+ FSB with 2000+ memory.
If you have 1600 ram then you get similar performance on ~1333 and 1600. On this platform most important is CPU-NB frequency not memory ( till some point ).
I would try something like 1066 memory divider with 300MHz FSB and lower CPU-NB like 2200-2400. If you make it run then try to go higher with CPU-NB.

 

[I.M.O.G.]

thanks, I will try those settings and let you know how it goes.

I have tried setting 280 and 270 Fsb with 1066 divider, which both crashed immediately. I will try lower cpunb settings while doing it like you suggest.

my goal is running 28, 29, or 30 multiplier with high FSB... right now only 31.5 and 31 are any good for me, and I need higher FSB to hit 8ghz with the lower multis.

more input appreciated? any other voltages I should tweak to help with fsb? northbridge voltage or anything?

 

[xsuperbgx]

If you put NB, HT, and memory multipliers way down at the lower multipliers, can you go to a higher fsb and boot?

 

[hokiealumnus]

I usually bump HT up to 1.25-1.3 too. CPU-NB to ~1.35V; 1.55V seems a bit too high, but I didn't go past 7.6GHz, so perhaps I'm out of my league (until I try again).

The biggest red flag I see is you are running CPU-NB at 2600+ MHz. When I was benching Bulldozer one thing I noticed right away was that it doesn't seem to like CPU-NB & HT frequency to be too high. Drop those multipliers so they're both closer to 2000 MHz and I bet you go higher on the FSB.

You're going for max frequency anyway, so it's not relevant where they are.

 

[I.M.O.G.]

thanks appreciate that help, I will be trying that tomorrow also hokie and will report back.

superbg: I will try that also. I dont know how low the multis will go and still boot, but 1066 is the lowest ram multi that will POST. I will try dropping everything else and report what happens.

 

[I.M.O.G.]

Getting back to testing this now, about to pull down temps...

 

[hokiealumnus]

Stream?

 

[I.M.O.G.]

CPU-NB and HT Link set to 6x Multi - that means they start out at 1200MHz.
CPU multi set to 10X - that means it starts at 2000MHz.
Memory set to 2.66 Multi (1066) - that means it starts at 533MHz.

vcore at 1.45V
CPU-NB at 1.3V
Ram set at 1.7V
HT set at 1.25V
Temps at -100C currently

Fine at 255FSB, crashed immediately at 260FSB.

 

[hokiealumnus]

Put CPU-NB @ 1.35 & HT @ 1.3. Raise NB a bit too, maybe 1.25-1.3.

 

[I.M.O.G.]

Stream is online at www.overclockers.com/overclockers-live

 

[I.M.O.G.]

CPU-NB and HT Link set to 6x Multi - that means they start out at 1200MHz.
CPU multi set to 10X - that means it starts at 2000MHz.
Memory set to 2.66 Multi (1066) - that means it starts at 533MHz.

vcore at 1.45V
CPU-NB at 1.3V
Ram set at 1.7V
HT set at 1.25V
Temps at -100C currently

Fine at 255FSB, crashed immediately at 260FSB.

All settings are the same, unless specified:

CPU-NB 1.35V
HT 1.3V
NB 1.25V

Temps are now -190C

At 259FSB it was fine, at 260FSB it locked up.

 

[I.M.O.G.]

So these are the timings and subtimings my ram defaults to for each divider:

1333 - 9-9-9-24-5-4-4-7-10-110-33-7-2-4-4-7.8-1T
1600 - 9-9-9-24-6-5-6-8-12-110-40-6-3-4-4-7.8-1T
1866 - 9-9-9-24-7-6-7-8-14-110-47-7-3-4-4-7.8-1T
2133 - 9-11-9-27-7-6-7-8-14-110-47-7-3-4-6-7.8-1T
2400 - 10-11-10-30-7-6-7-8-14-110-47-8-3-4-6-7.8-1T

Leaving everything at auto and ram voltage at 1.65V or 1.7V, it posts fine defaulting to all of those settings.

Going to try manually setting all timings and see if that has any effect on my FSB limits. Also going to use a higher CPU-NB multiplier, like 10 or 11, just to ensure that remains higher than the ram frequency.

 

[I.M.O.G.]

Manually setting the 2400 timings, CPU-NB and HTLink were set to 11x, Vcore was 1.4, CPU-NB volts were at 1.3V and...

Using the 1600 divider, I was able to hit 245FSB (980/1960MHz on the ram). (250FSB immediately crashed)

Using the 1333 divider, I was able to hit 250FSB (833/1666MHz on the ram). (255FSB immediately crashed)

Using the 1066 divider, I was able to hit 255FSB (678/1356MHz on the ram). (260FSB immediately crashed)

Using the 800 divider, I was able to hit 260FSB (520/1000MHz on the ram). (265FSB showed up on CPUz, then crashed seconds later)

So loyal OCF readers, my question to you is this: What does this mean? (I have no idea)

 

[I.M.O.G.]

Further information for anyone hazarding a guess...

Manually setting the 1333 timings in post #13, CPU-NB and HTLink were set to 11x, Vcore was 1.4, CPU-NB volts were at 1.3V and...

Using the 1600 divider, I was able to hit 245FSB (980/1960MHz on the ram). (250FSB immediately crashed)

Using the 1333 divider, I was able to hit 245FSB (816/1632MHz on the ram). (Crashed within 10 seconds, before I was able to try 250FSB)

Using the 1066 divider, I was able to hit 255FSB (678/1356MHz on the ram). (260FSB immediately crashed)

Using the 800 divider, I was able to hit 260FSB (520/1000MHz on the ram). (265FSB immediately crashed)

So again, my question to you is this: What does this mean? (this is not a trick question)

 

[I.M.O.G.]

Good news is it looks like I can actually use the 800 divider, which could give me 260 or a bit above, which may get me to 8.2GHz if the chip can do it.

Bad news is, I still can't hit 270 or 280 FSB, which I would need in order to try multis like 29 or 30x.

So do you think its the ram or the board? Seemed a bit more unstable using the tighter timings, with all other settings the same... So I think my last two posts mean that maybe its a weird ram problem, and not a board limitation?

 

[Seebs]

Matt...

Why don't you fire of a PM to *Chew at his normal stomping ground. He was able to get his board to do 275 with ease.
I should have asked more specific questions about how he ran his settings back at that event... All he said was "Run 275FSB and go to the high 20s for multis" that's how you'll get the high clocks... But I neglected to ask about NB, HTT, etc.

I remember he showed me the RAM he was running after the event and they were G-Skills. Some PSC kits he said. They were 2000MHz 6-8-6 if I remember correctly.

 

[I.M.O.G.]

Done, let him know I'd appreciate input if he's not too busy. Also PM'd Redduc900, he may have an opinion on something like this.

Hopefully its ram and when the gskill flares show up, I'll be ripping and tearing.

 

[Seebs]

I'll PM him as well.

 

[hokiealumnus]

Unless he has gotten something different, the Flare kit on its way to you is the same kit chew* uses.