[mythtv-users] VDPAU blows up video card, film at 11

Dale Pontius DEPontius at edgehp.net
Sun Jan 18 23:47:04 UTC 2009


Brian Wood wrote:
> On Sunday 18 January 2009 06:09:09 ryan patterson wrote:
>> On Sun, Jan 18, 2009 at 1:22 AM, Yeechang Lee <ylee at pobox.com> wrote:
>>> Robert McNamara <robert.mcnamara at gmail.com> says:
>>>> [A]t least one Myth dev (who knows quite a bit moer about myth than
>>>> the average user) has a permanently *physically damaged* card as a
>>>> result of testing VDPAU.
>>> !!! Tell us more.
>> Yes please explain how that is possible.  I don't want to call you a
>> lier, but it is inconceivable for software to "physically damage" a
>> hardware device (corupting firmware or overclocked hardware situations
>> both don't apply).
> 
> Perhaps the video card got tossed across the room?
> 
> I have certainly felt like doing that on occasion.
> 
> Monitors used to get blown up by driving them beyond their capabilities. The 
> only way I can think of to damage a card would be by over-heating somehow.

The simplest way to cause permanent damage with software would be some
section of circuitry with some under-designed metalization.  Normally
all would be fine, but it's believable that there would be some
combination of software operations that would drive that section of
circuitry into its highest-power state.  When it's slow, it's considered
electromigration.  (one of those things that kills overclocked chips,
with time)  When it's fast, you might as well call it a fuse.  It can be
in power distribution, or possibly at the drive point of a heavily
loaded signal.

The original Intel 80286 had a similar fail, though it didn't carry
permanent damage.  In that case, under specific combinations of register
contents, execution opcode, temperature, and applied voltage, a certain
section of the chip could "brown out", causing a lockup.  In that case,
weak power busing could reduce the available voltage in that area below
the minimum necessary, but the currents involved were too small to cause
permanent damage.

As others have mentioned, there was the old case of blowing up monitors
with improper sync.

Dale Pontius


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