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FSB limiting Overclock

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gothpyre

Registered
Joined
Jan 6, 2010
AMD Athlon 64 x2 4000+(Brisbane)
2gig ram Kingston ddr2
BioStar Mobo-Mcp6pb M2+ Rev. 6.00

I have been trying to overclock my brisbane but I cant seem to raise my fsb over 253 with my mutiplier at x10.5. I tried lowering the mutiplier and it still wont post past 253. Most of the time my bios won't even boot until I reset the cmos(or reboot like 50 times). I don't see any temperature problems. I also raised the voltage, tried changing the timeing and voltage on the ram. I feel like my mobo limits me on how hi I can raise the fsb, even with a lower multiplier, it just does not make sense. I hate biostar, there are enough overlcocking options to taunt me but I am limited to how much I can change. If you need more info just ask.
 
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theflyingrat

Member
Joined
Apr 20, 2001
Location
St. Paul, MN, USA
If it stops at a certain HTT bus speed, even after lowering the CPU multiplier, you've got one of two problems.

a) That's as far as the motherboard will stably operate the CPU. There is a point where the HTT speed just can't be pushed any further without losing its signal integrity.
b) Your memory has hit a wall; you'd usually have to lower the memory multiplier to keep it within its operating spec.

To be honest, 253HTT is way faster than a micro-ATX board with a skimpy 3-phase VRM, based on the dumpy GeForce 6150 chipset has any right to go. Lots of these won't ever go higher than 220HTT before something goes stupid. On top of that, the power circuitry on the board will only support a 95W CPU, so overclocking will never be its high point to begin with.

But before giving up on it, check your memory and HT Link multipliers. If you can lower both of these and it still won't clock up, you're simply motherboard-limited, something that I wouldn't see as a surprise one bit.
 

Parad0x420

Member
Joined
Jun 22, 2007
Location
Dark Side of the Moon
Could you post come CPUz screenshots of your current OC? Showing us the CPU and HT link speeds along with your RAM tab. When bus clocking, you're increasing several things at the same time, so you might have to compensate by lowering the multiplier on your HTT and using a lower RAM divider. The board has the option of going that high on the FSB setting, but most of the time you will never reach that. Some boards just top out at a certain point and won't allow you to go any higher regardless of what settings you try.
 

DragoXT

Member
Joined
Jun 14, 2005
It sounds to me that your need to drop your LDT multi down if you left it on auto. You also need to make sure that your RAM can do those speeds, or have them on a divider so that they run at stock speeds to take that out of the equation. For brisbanes you want to try and keep that HT speed under 1000mhz, and dropping that LDT multi down to like 3x should do that for you at the speeds you are pushing that fsb/htt.
 

Bobnova

Senior Member
Joined
May 10, 2009
That's a pretty impressive OC for that set of parts, just so you know. Follow what the guys above have said and you may well get even more, but don't be too shocked if your mobo simply won't do it, you've already squeezed out more then many people have been able to.
 

EarthDog

Gulper Nozzle Co-Owner
Joined
Dec 15, 2008
Location
Buckeyes!
You dont have a FSB, its HTT. ;)

I havent heard of that board so I cant speak with a lot of merit, but if you lowered your HT and are keeping it at or below 1000, your memory is at stock speeds or known stable, you may have topped out.

Some CPUz screenshots would be helpful for us to help you better.
 

Parad0x420

Member
Joined
Jun 22, 2007
Location
Dark Side of the Moon
You dont have a FSB, its HTT. ;)

I havent heard of that board so I cant speak with a lot of merit, but if you lowered your HT and are keeping it at or below 1000, your memory is at stock speeds or known stable, you may have topped out.

Some CPUz screenshots would be helpful for us to help you better.

This is true, but the setting that you change in BIOS is actually still labeled "FSB". So, to make sure he knows what we're referring to, it makes more sense to call it that for now.
 

EarthDog

Gulper Nozzle Co-Owner
Joined
Dec 15, 2008
Location
Buckeyes!
Wow, really? Thanks for that. Maybe I should keep my nose in the Intel world that I know best. But whats weird, I never had a S754/939/AM2 that listed it as FSB before (though i only had about 6 boards from those gens).

Thanks for that info and correction! :)
 

Parad0x420

Member
Joined
Jun 22, 2007
Location
Dark Side of the Moon
Haha, no problem Earth. It may not be all boards that do it, but some of the ones I've used still label it that way. And by the way the OP described his question, I'm guessing that it is displayed the same way. But you're still essentially right, it is the HTT. :)
 

EarthDog

Gulper Nozzle Co-Owner
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Dec 15, 2008
Location
Buckeyes!
Doesnt look bad. Seems comparable to the Xig... which is a solid bang for your buck cooler. :)
 

Bobnova

Senior Member
Joined
May 10, 2009
From the CPUz shot i can see that your HT-Link speed is very high for a brisbane (they don't like >1000), somewhere in the bios there will be a multiplier for setting it, you want to drop that multi from 5x to 4x or 3x. Someone above this post said it's called LDT in your board, i've never used it so i don't know.
 
OP
G

gothpyre

Registered
Joined
Jan 6, 2010
I don't have an option to change the ht multiplier in my bios or ldt, I looked for both of those just now. The only thing ht related that I can change is the voltage. The only thing in bios that lets you change the multiplier by 5x 4x 3x is under the pci express part. Also my video card is and ati radeon 4650 512 meg card.
 

Parad0x420

Member
Joined
Jun 22, 2007
Location
Dark Side of the Moon
From the CPUz shot i can see that your HT-Link speed is very high for a brisbane (they don't like >1000), somewhere in the bios there will be a multiplier for setting it, you want to drop that multi from 5x to 4x or 3x. Someone above this post said it's called LDT in your board, i've never used it so i don't know.

I had suggested that to him back when I thought his 1150 HT was high.
I also see only 1.328v for your Vcore.. I'm a little surprised that it's that low, but it might be able to go further with a Vcore increase.
 

EarthDog

Gulper Nozzle Co-Owner
Joined
Dec 15, 2008
Location
Buckeyes!
Yikes, doesnt sound like a solid overclocking board... Where is QuietIce when you need him... :)
 

Parad0x420

Member
Joined
Jun 22, 2007
Location
Dark Side of the Moon
I don't have an option to change the ht multiplier in my bios or ldt, I looked for both of those just now. The only thing ht related that I can change is the voltage. The only thing in bios that lets you change the multiplier by 5x 4x 3x is under the pci express part. Also my video card is and ati radeon 4650 512 meg card.

I can't remember where the setting for HTT was on my old A8N32SLI-Deluxe, but it might have been under the chipset config, or possibly around the PCIe config.. can you tell us what settings it displays for those multipliers? It might be those that you found there.

Found this in QI's writeup
Advanced/Chipset

ChipsetSm.JPG


K8 to NB Frequency: This is commonly known as the HT multiplier. Stock setting is [5X] and is usually adjusted downward to allow for a faster clock speed. The HT bus* is advertised to run at 1000 MHz (200 x5) but most of the time it'll go 1100+ MHz. Finding the top speed of the HT bus is one of the goals when testing your system. Mine went to 1130 MHz before becoming unstable so with a 233 clock speed I need a [4X] setting since 233x5 is 1166 MHz (>1130). Generally it's a good idea to keep the HT bus at 1000 MHz or less unless you've extensively tested yours and know it can run faster.
*Edit: Newer versions of CPU-Z show this as "HT Link".

K8 to NB LinkWidth: Should be set to 16v16^ as shown. (Edited, Thanks Zx2Slow)

SB to NB Frequency: Leave this at 5X to avoid problems.
Edit: Some people have gotten higher FSBs setting this to 4X but only for extreme (300+ MHz FSB) overclocks.
(Thank you, redduc900)

SB to NB LinkWidth: Should be set to 16v16^ as shown. (Edited, Thanks Zx2Slow)

Primary Graphics Adaptor: Should be set so your primary video card slot is listed first. I only have one card and it's in the bottom slot - the top PCIe slot is PciE1. This setting does make a difference - I had stability problems when it was set at default with PciE1 first.
Edit: For those of you installing a dual GPU card (i.e., the nVidia 7950) you need to put it in the LOWER (black) slot to get dual x16 graphics.
Do your settings resemble these? If so, that's your HT multi.
 
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