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PCIe frequency - Auto or 100mhz?

14193 Views 10 Replies 10 Participants Last post by  StenioMoreira, 
J
Hi all

My first OC, would somebody care to explain why the PCIe frequency should be at 100mhz? I'm guessing it has something to do with the NB frying.

Would it be safe to let it run on Auto? This is the only way I can get my PC to boot when OC'ing at high clock frequencies.

I think it's worth noting that I cannot boot at frequencies higher than 3.2ghz. I haven't tried doing anything with the RAM yet, though.

Rig:
Mobo: Gigabyte GA-G31M-ES2L
CPU: Q6600

Thanks in advance for any advice.
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D
Leave it on Auto.

It has nothing to do with CPU overclocking.
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Danker16
the PCIE frequencie should always be 100MHZ, lokc it at 100MHZ if want to avoid random BSODs and freeze ups
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V
2
Quote:

Originally Posted by Jurras View Post
Hi all

My first OC, would somebody care to explain why the PCIe frequency should be at 100mhz? I'm guessing it has something to do with the NB frying.

Would it be safe to let it run on Auto? This is the only way I can get my PC to boot when OC'ing at high clock frequencies.

I think it's worth noting that I cannot boot at frequencies higher than 3.2ghz. I haven't tried doing anything with the RAM yet, though.

Rig:
Mobo: Gigabyte GA-G31M-ES2L
CPU: Q6600

Thanks in advance for any advice.
It should be safe to left it be on auto yes.

As for booting, underclock your ram and loosen the timings. Then try to boot. Also, what vcore are you running?

Edit:

Quote:

Originally Posted by Danker16 View Post
the PCIE frequencie should always be 100MHZ, lokc it at 100MHZ if want to avoid random BSODs and freeze ups
Although it's true that PCIE frequency should stay near 100, leaving it on auto is not a problem at all and WILL NOT lead to crashes or freeze ups.
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M
I always leave it on auto, since it only effects your gpu, but I remember someone I respected on the forum saying that if you raised it to 103-109 or something that it could actually make an unstable system more stable, or something like that. That it was some trick of high-end overclockers.

Also, there is some evidence that slightly raising that bus clock can improve frames by a few per second, but I've never verified this myself.
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P
Quote:

Originally Posted by Mygaffer View Post
I always leave it on auto, since it only effects your gpu, but I remember someone I respected on the forum saying that if you raised it to 103-109 or something that it could actually make an unstable system more stable, or something like that. That it was some trick of high-end overclockers.

Also, there is some evidence that slightly raising that bus clock can improve frames by a few per second, but I've never verified this myself.
It was the 9600GT's I remember, upping the PCIE Freq slightly actually gave noticeable gains. No idea what other cards it affected of it was only the G94 core.
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D
Quote:

Originally Posted by Mygaffer View Post
I always leave it on auto, since it only effects your gpu, but I remember someone I respected on the forum saying that if you raised it to 103-109 or something that it could actually make an unstable system more stable, or something like that. That it was some trick of high-end overclockers.

Also, there is some evidence that slightly raising that bus clock can improve frames by a few per second, but I've never verified this myself.
No.... PCIe frequency affects any devices on PCIe which may include NICs, storage controllers, audio devices, etc.
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corky dorkelson
Upping the PCIE frequency too far can and will cause data corruption with SATA hard drives. Just something to keep in mind. I have heard of corruption happening as low as 110mhz. That is why people almost always advise keeping it locked at 100. In some circumstances with a really high FSB OC, upping the PCI-e freq can help stabilize an OC.

I personally have never gone beyond 110mhz (one of my budget boards needed a bump in PCI-e for a any OC at all).
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G
We at the GAEP45-UD3P Thread tend to lock it at 100MHz, more as a due diligence, consistency thing than a real practical matter.
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B
A few MHz bump in PCI-E frequency often increases the max stable BCLK on LGA-1366 setups. Without modification, only a handful of X58 boards can maintain stability with more than 102MHz PCI-E or 222MHz BCLK.

Also, my EeePC 900 (Celeron M version) can't run the FSB more than ~10MHz faster than the PCI-E frequency. So, to get 133MHz FSB stable on it, I need to run the PCI-E bus at around 124MHz.

There are risks with upping the PCI-E frequency that can become a very big deal after about 110MHz, and most platform see no benefit from boosting it. So, it's best left alone unless you have good cause to think that it could help.

Anyway, as for auto vs, 100MHz. I usually set 100MHz manually, not that this is usually necessary.
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StenioMoreira
hello guys I increased Pcie frequncy to 117 mhz but now i got these 2 settings --> Plx Core voltage and Plx Aux voltage. They both on auto and i want to set a voltage myself as auto always pushes things too far. And advice on voltagess?? what is a conservative Core and Aux plx voltages??? im guessing only thing i need to mess with is Aux and for core idk what that does. They both under Pcie tuning section after i increased pcie frequency
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