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Indulge my PCIe speed query.

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ogboot

Member
Joined
Jul 8, 2003
A long time ago, (that's relative, but a/w) when I started overclocking I couldn't afford the top of the line mobos that had PCI locks. Most of my O/C at that time was on VIA chipsets like the kt600, and all kinds of bad things would happen when your pci bus speed went too high (over 35mhz would start causing hard drive corruption on most of my setups for instance).

Now fast forward, I didn't have these issues on any of my C2D platforms, but here we are with i5. I see several posts in this section referring to increased pci-e speed for more stable overclocks. Wouldn't this cause undue stress on components like graphics cards that rely on that bus? What PCI-e speed is considered "safe" or "tolerable" to your average add in card? I'm not going to risk a very good video card for the sake of 200mhz on my cpu.

Someone please enlighten this wayward soul. Thanks in advance.
 
A "safe" or "tolerable" PCIe bus frequency on a Lynnfield is 100MHz. It was originally thought that when increasing the BCLK, the PCIe fequency also increased because the two are tied together. But in reality all Lynnfield CPUs use an independent clock generator for the PCIe controller with a nominal frequency of 100MHz (the PCI Express clock setting in the BIOS of most i5 boards is adjustable from 100MHz - 200MHz). So in essence raising the BCLK on a Lynnfield system won't push the PCIe bus out of spec. Unless you plan on running a BCLK of over 200, I would suggest just leaving the PCIe bus frequency at the default of 100MHz.
 
that sounds like great advice redduc and i completely agree, I was just curious because some people were claiming that increasing the pci-e frequency was giving them higher overclocks. after all the joy we've all experienced from pci locks I was surprised to see talk of increasing said clock. Not worth the risk in my opinion.
 
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