Oscilloscope

[negev]

Is there an easy way to connect an oscilloscope to a pc to monitor clock signals from the motherboard?

Something with a pci card would be good, which would then let you flick between the different signals so you can fine-tune overclocking.. much easier than trying to manually hold the terminals in the right place..

I'd be willing to pay for something like this

[Sailindawg]

Glad to see that you read the article I suggested. I don't know how Praz obtained those oscilloscope readings for his article. He can be contacted over at DFI Club or through his own site www.edgeofstability.com. I have read his posts for quite a bit over at the now defunct DFI-Street and he's a very knowledgeable overclocker / enthusiast / engineer. Praz still seems to work for DFI and has access to all sorts of labs and gear. Some type of PCI slot type of solution would be great. It would take some of the black magic aspect of OC'ing away.

Edit: the edge of stability contact link is broke. :down:

[negev]

Does the blackops have voltage measurement points like that DFI board does? A quick look at the motherboard layout on google images suggests it has at least one.. i can't be bothered to open my case right now lol

[gmcg]

Is there an easy way to connect an oscilloscope to a pc to monitor clock signals from the motherboard?

Something with a pci card would be good, which would then let you flick between the different signals so you can fine-tune overclocking.. much easier than trying to manually hold the terminals in the right place..

I'd be willing to pay for something like this
IMO it makes no sense, because:

1. to adjust "ringing" during overclocking - as for example GTLREF level, you need an extremely fast oscilloscope, such device will cost a fortune, in addition its signal cable will add some capacity to the circuit and at such frequency it may change everything - form of the signal, or for example, circuit may oscillate with a cable and be good enough without it.
http://www.thetechrepository.com/showthread.php?t=87]

2. it is not easy to connect oscilloscope to a necessary signal point, usually those points are pretty small - see the pictures above.

3. adjustment with finding for example "stable point" while your PC is tested during hours under stress is the optimal result to avoid ringing, therefore even if you will get the best signal form with oscilloscope, you still will need to re-adjust and re-test your system for stability disconnecting the signal cable of oscilloscope, such as parameters of the circuit will be different.

Here is a good article about such things http://www.sigrity.com/papers/2005/s17p6.pdf Here is the lowest price for refurbished Tektronix TDS6604, used for such measurements:
http://www.testequipmentconnection.com/products/6031
Of course there are even better models http://www2.tek.com/cmswpt/psdetails.lotr?ct=PS&ci=13458&cs=psu&lc=EN but price ...

It is pretty doubtful that anyone needs it just for overclocking of his motherboard, negev ...

[negev]

Oh well guess that ideas out the window :P

[Gendo]

Yeah I guess you'll just have to raise the voltage to get your stuff stable. Like the rest of us:rofl:

Or you'll have to settle for 100Mhz less on your ram. Which btw you'll never notice.

[saaya]

well, i visited oskar wu himself in his lab a few months ago and he was playing with a 20ghz scope :D
but he told me theres not so much you can really get from the results... it helps you to understand whats going on and MIGHT give you a hint at whats wrong, but thats about it... like gmcg explained meassuring those high speed signals is really difficult, cause as soon as you add a probe itll change everything... so you have to use active probes, which cost a lot and, while not beeing so capacitive, still influence the circuit quite notably.

so whenever you attach the probe and manage to get something working well, as soon as you remove the probe things are worse than before...
and its not just about adding another resistor or increasing or reducing some voltage to get back to the state the probe caused...

we have a couple of 20ghz scopes here and theres a lot of neat things you can do with them, but its all just helping and giving you hints... its not really all black and white ultimate xray stuff like you might think... i was quite dissapointed cause i originally thought those scopes will be very useful to figure out whats going on and improving circuits, but they arent nearly as useful as i thought...

and just to give you guys a heads up, nehalem has a built in debug interface cause the memory speeds and qpi speeds are way beyond anything you could reliably meassure externally... no matter how much money you spend on a scope and get a super mega ultra 100Ghz scope, which intel certainly could, it wont help you...

BUT, meassuring voltages should be fine, i mean you can zoom in indefinately and still see more details, but to check vcore stability and vdroop a scope is still very reliable for, at least afaik...

[HDCHOPPER]

sounds like quantum physic ! once ya looked at it youve changed it:rofl:

[saaya]

thats where the idea for QuantumForce comes from :D
i love quantum mechanics... there is still magic down there in this miniature world all around us that science hasnt manage to kill yet :D