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Re: [Xen-users] VGA/PCI Passthrough of Secondary Graphics Adapter




I'm not disputing that FLR makes it easier. What I am saying, however, is that if the driver is written without cutting corners and making assumptions, it should be able to manually re-initialize the device.

I totally wish that was the case, if you find a linux method of doing this I would love to know about it.

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With the reliability record you describe above, that makes VGA passthrough stability as close to useless as it can possibly get.


The installation process is super buggy, but after getting it installed correctly I have had it working just fine for months. ÂKeep in mind I was running Wheezy (unstable) and Xen 4.2 (unstable a the time), so I was more concerned with "can it work" than "is it stable".


Uhh... You are saying that the ATI card shows up as an ejectable device in the Windows VM? Really??

/me goes to check

Typical - after the VM booted perfectly every time for the last 2 days, now I get nothing but a BSOD (failed attempt to reset the display driver) every time - and I'm doing this on a freshly rebooted machine.


I posted a youtube video showing the whole process, I demonstrate ejection @21:25Â


I point my fingers at FLR because its described responsibility is to
reset device state in virtual environments, and every one of the
problems I have encountered appear to be linked to the state of the
card. ÂHowever, other users have posted very different experiences,
leading me to believe that it could well be hardware specific.

I suspect it's down to shoddy drivers. Has anyone actually reported problems with a supported Quadro card ([246]000 or FX [345]800)?

Not the mailing lists, but as supported devices (as per the wiki) I'm willing to bet nVidia has been contacted for troubleshooting support.


I started with a consumer nVidia card, it didn't work that's why I
switched to AMD. ÂIf you can share the model of a $180 USD consumer
nVidia card with HDMI out and onboard audio that can be converted to a
working Quadro model card and is equal to or outperforms my AMD I would
gladly switch.

GTX680 and GTX690 have been done:

http://www.eevblog.com/forum/projects/hacking-nvidia-cards-into-their-professional-counterparts/msg207550/#msg207550

Note: Small amount of soldering required.

I saw that, would be awesome if I had a bit of extra cash, but more if someone can confirm that it works.
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But they don't fit in the $180 budget envelope. It does look very much like most Nvidia cards are modifiable to equivalent quadros (those that have reasonably equivalent Quadros at least).

I'm just getting a genuine low-end Quadro (for hopefully <= Â130) first to make sure it'll work, before I get something higher end for modifying.

I'm vaguely tempted by a Titan, but the problem is that the only equivalent enterprise grade card is a Tesla, which means no video out, which would somewhat defeat the purpose. Then again, there seems to be evidence that the number of shaders doesn't have to match with what the Quadro model is expected to have - it looks like the hardware capabilities get auto-deteced correctly.


>From what I have seen the Quadro 2000 is the earliest
model with onboard audio, and none of them have HDMI out so you would
need a DisplayPort to HDMI adapter, plus they cost double what I paid
for my card. ÂIf you compare passmark benchmarks my card has a 60%
performance gain over a Quadro K2000, and 30% over the Quadro 4000 which
costs four times as much. ÂGoing back to the lack of demonstration
videos really makes me wary of throwing that much money into a
"possible" alternative, especially one that performs worse than my
current. ÂWhile I have seen emails mentioning Quadro, that's about it.

Expect a report back from me on this as soon as I get my hands on a Quadro (2000 or FX3800, I have no intention of spending more than a bare minimum). My priority is to have something that works, and works _reliably_.

That is something to look forward to, please do send out details if you get a Quadro and it works. ÂIf it does no longer having to eject on reboots might be worth the drop in performance.
Â

 No instructions or demonstration videos or performance comparisons.
 Makes me a bit wary about dropping four times the cost of my current
card for less performance when the only supporting documents are various
emails and a wiki page.

Let me flip that one around - there are plenty of blog entries and videos of ATI cards working, and yet there are several recent posts on this list about using ATI cards and VGA passthrough working at best unreliably, and more often not working at all. Don't fall into the "It must be true, I read it on the internet!" trap. :)

A good rule to follow to be sure, and that's why I like detailed supporting information and demonstrations.
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