Fair enough, your different perspective is at least as valuable as mine ! There is so much I still need to learn myself, I wouldn't dare say I know the truth and anyone else is wrong.
I think your experience is incredibly valuable and useful. You mentioned you had BSOD 7B on 15-20 computers which is a whole lot more than most people on this forum ever use... I only have at hand 3 or 4 different machines, which are not even all really mine... However the fact that you haven't yet seen a machine that is "too fast" or one that is "slow enough" doesn't mean it will never happen in the future. And this leads to the next step:
Your pragmatic approach is perfectly fine. But caring about "universality" is in itself is a good enough reason to try to understand the root cause of the problem, in order to come up with a solution which is known to be future-proof, and not just a tweak which "happens to work today, but may not work tomorrow"
Till we have absolutely irrefutable evidence, all we can do is speculate that this or that is happening. Any hypothesis can (within limits of reason) be thought to be true, as long as a counter example is not found (i.e. a BSOD 7B is not seen).
You are right, it is very trial and error, and I have no idea if this will necessary continue this way. IMO, even 15 data points is not very many. I think its enough to spot a very strong link, but I'm guessing I'd need hundreds to escape the statistical uncertanties.
It is obviously very time consuming, but if you can check that all three solutions behave the same 100% on many machines (the more the better !), that will be very informative ! As long as we don't find a counter-example, we cannot rule out the fact that is purely down to timing...
In fact there might be a fourth option (at least for XP):
You can try to replace the standard usbhub.sys file with the version from XP Embedded SP3 (from http://iorboaz.blogs...ndows-2003.html) or from the Feature Pack 2.
This has also given me 100% success, but that was only on 4-5 different machines. If you have the time, it would be interesting to test on many more !
But anyway for Win7 I don't know if in there is also a variant of usbhub.sys to be taken from Win7 Embedded.
Well, I am using Windows 7, so I can't that embedded driver...
As far as the other solutions, I'm thinking that I can't see the harm in going with the kitchen sink approach. From a practical standpoint, I can't see the harm in including ubdrvgd.sys and cdob's changes. Based on the working theory, its probably not necessary, but I'm hesitant to flat out leave the ubdrvgd solution as I've had zero problems in the last few days - and as you might guess its sort of important for me that I have a working tool on hand since I'm using it on a daily basis.
Edited by Agent_Smith, 03 May 2011 - 03:40 PM.