What's your opinion about PCI Express overclocking ? How to stress test it ?

[creativus]

I just reached a stable CPU overclock but along the way I've read a few threads about PCI Express overclocking. Some fps gains seem possible, especially on the low side, but when I increased my PCI Express frequency from 100MHz to 108MHz I got a boot failure. Right now it's on 104MHz but I don't know how to stress test it.

Any ideas ?

 

[Woomack]

It highly depends on the CPU and additional devices. Some will fail when you set too high clock and this clock can be ~103MHz or more. If you have a locked Intel CPU then for some generations, the max clock is usually ~103MHz or something near. AMD motherboards sometimes dislike anything higher too.
You can run PCIe bandwidth benchmark which is in the latest 3DMark but I guess this test isn't free. Usually, storage devices are failing first. SSD should be able to work up to at least 110-115MHz but it's not a rule.
I don't think that PCIe OC has any point. I mean you may see a 1% performance gain in some benchmarks but in reality, it won't really matter.

 

[EarthDog]

Pointless since the gains are mostly negligible and it can cause system instability.

 

[Evilsizer]

interesting forum update....

PCIE buss is tied to the sata controller, instability will cause data corruption. there is no stress testing the PCIE buss, for me i had no problems running 104 pcie in the day. it did off a bit of a fps boost but we are also talking much older hardware where the more bw to the card helped. it isnt work it but with overclocking even set to 100 you can still have some issues, to make sure it hard locks the clock just set it to 101mhz.

 

[EarthDog]

Why touch it at all? Default is perfectly stable.

 

[Woomack]

Some generations ago, you could improve the max storage bandwidth or graphics card bandwidth but right now I'm not sure how it could help.

 

[Evilsizer]

Why touch it at all? Default is perfectly stable.

not all core 2 boards were able to lock 100mhz, it would fluctuate. By setting it to 101, boards were able to hard lock it with no fluctuation. all of mine i did made it more stable for overclocks. we know that will always vary but i can only say on the Abit boards, not the other brands.

 

[EarthDog]

Clocks fluctuate naturally though, right? If you want to stop the fluctuating, disable spread spectrum.

 

[Evilsizer]

i was never sure what that option did back in the day, i never messed with it. on motherboards it more possible they fluctuate, i say i think on this case. just because of all the stuff going on a computer motherboard with other connections or buss talking to devices. some devices on board may have wiggle room on the variations of clock speed. take this merely as musings from being a old over-clocker and not a EE or a more knowledgeable overclocker like NickShih that had his hands on this beauty.

still has a 4790k in it i think, also i couldnt remember the sytax to end the url= section to attach to a word LOL. every time i thought i had it and typed more it made the rest part of the link. *face palm crap, still doing it and the avatar's not poping up now using the *name* god im bad now